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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

☒Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the fiscal year ended December 31, 2016

☐Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Commission File Number: 001-15369

WILLIS LEASE FINANCE CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (415) 408-4700

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None.

Indicate by check mark if the registrant is a well-known seasoned issuer as defined in Rule 405 of the Securities Act.   Yes ☐  No ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.   Yes ☐  No  ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.   Yes ☒  No ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).   Yes ☒  No ☐

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendments to this Form 10-K.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes ☐  No ☒

The aggregate market value of voting stock held by non-affiliates of the registrant as of the last business day of the registrant’s most recently completed second fiscal quarter (June 30, 2016) was approximately $81.9 million (based on a closing sale price of $22.23 per share as reported on the NASDAQ National Market).

The number of shares of the registrant’s Common Stock outstanding as of March 6, 2017 was 6,399,767.

The Company’s Proxy Statement for the 2017 Annual Meeting of Stockholders is incorporated by reference into Part III of this Form 10-K.

WILLIS LEASE FINANCE CORPORATION
2016 FORM 10-K ANNUAL REPORT

TABLE OF CONTENTS

PART I

ITEM 1.BUSINESS

INTRODUCTION

Willis Lease Finance Corporation with its subsidiaries is a leading lessor and servicer of commercial aircraft and engines.  Our principal business objective is to build value for our shareholders by acquiring commercial aircraft and engines and managing those assets in order to provide a return on investment, primarily through lease rent and maintenance reserve revenues, as well as through management fees earned for managing aircraft engines owned by other parties. As of December 31, 2016, we had a total lease portfolio consisting of 208 engines and related equipment, 11 aircraft and 5 spare parts packages with 80 lessees in 43 countries with an aggregate net book value of $1,136.6 million. In addition to our owned portfolio, as of December 31, 2016, we managed a total lease portfolio of 542 engines and related equipment for other parties. We also seek, from time to time, to act as a leasing agent of engines for other parties.

In 2013, we launched Willis Aeronautical Services, Inc. (“Willis Aero”), a wholly-owned subsidiary, whose primary focus is the sale of aircraft engine parts and materials through the acquisition or consignment from third parties of aircraft and engines. 

In 2016, we purchased, through our wholly owned subsidiary Willis Asset Management Limited (“Willis Asset Management”), the business and assets of Total Engine Support Limited (“TES”).  TES has been the engine management and consulting business of the TES Aviation Group. Willis Asset Management has 502 engines under management as of December 31, 2016.

We are a Delaware corporation, incorporated in 1996. Our executive offices are located at 773 San Marin Drive, Suite 2215, Novato, California 94998. We transact business directly and through our subsidiaries unless otherwise indicated.

We maintain a website at www.willislease.com where our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and all amendments to those reports are available without charge, as soon as reasonably practicable following the time they are filed with or furnished to the SEC. You may read and copy any materials we file with the SEC at the SEC’s public reference room at 100 F Street, NE, Washington, DC 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0300. The SEC also maintains an electronic Internet site that contains our reports, proxies and information statements, and other information at http://www.sec.gov.

We separate our business into two reportable segments, Equipment Leasing and Spare Parts Sales. Our business activities by reportable segment are described below.

Equipment Leasing

Our strategy is to lease aircraft engines and aircraft and provide related services to a diversified group of commercial aircraft operators and maintenance, repair and overhaul organizations (“MROs”) worldwide.  Commercial aircraft operators need engines in addition to those installed on the aircraft that they operate. These spare engines are required for various reasons including requirements that engines be inspected and repaired at regular intervals based on equipment utilization. Furthermore, unscheduled events such as mechanical failure, Federal Aviation Administration (“FAA”) airworthiness directives or manufacturer-recommended actions for maintenance, repair and overhaul of engines result in the need for spare engines. Commercial aircraft operators and others in the industry generally estimate that the total number of spare engines needed is between 10% and 14% of the total number of installed engines. Today it is estimated that there are nearly 45,000 engines installed on commercial aircraft. Accordingly, we estimate that there are between 4,200 and 5,900 spare engines in the market, including both owned and leased spare engines.

Our engine portfolio consists of noise-compliant Stage III commercial jet engines manufactured by CFMI, General Electric, Pratt & Whitney, Rolls Royce and International Aero Engines. These engines generally may be used on

one or more aircraft types and are the most widely used engines in the world, powering Airbus, Boeing, McDonnell Douglas, Bombardier and Embraer aircraft.

The Company acquires engines for its leasing portfolio in a number of ways.  It enters into sale and lease back transactions with operators of aircraft and providers of engine maintenance cost per hour services. We also purchase both new and used engines that are subject to a lease when purchased and on a speculative basis (i.e. without a lease attached from manufacturers or other parties which own such engines).

Spare Parts Sales

Our wholly owned subsidiary Willis Aero primarily engages in the sale of aircraft engine parts and materials through the acquisition or consignment of engines from third parties. The launch of this business segment in November 2013 positioned our Company to provide end-of-life solutions for the growing supply of surplus aircraft and engines. With the establishment of Willis Aero, we are able to manage the full lifecycle of our lease assets, enhance the returns on our engine portfolio and create incremental value for our shareholders.

THE WEST II SECURITIZATION

Willis Engine Securitization Trust II, or “WEST II”, is a special-purpose, bankruptcy-remote, Delaware statutory trust that is wholly-owned by us and consolidated in our financial statements. We established WEST II in September 2012, when WEST II issued and sold $390 million aggregate principal amount of Class 2012-A Term Notes (the “Notes”) and received $384.9 million in net proceeds. We used these funds, net of transaction expenses and swap termination costs, together with our revolving credit facility, to pay off the prior Willis Engine Securitization Trust, or “WEST” notes totaling $435.9 million. At closing, the net book values of 22 engines were pledged as collateral from WEST to the Company’s revolving credit facility, which provided the remaining funds to pay off the WEST notes. The assets and liabilities of WEST II will remain on the Company’s balance sheet. A portfolio of 58 commercial jet aircraft engines and leases thereof secures the obligations of WEST II.

WEST II’s obligations under these notes are serviced by revenues from the lease and disposition of its engines, and are secured by all of its assets, including all of its interests in its engines, its subsidiaries, restricted cash accounts, engine maintenance reserve accounts, all proceeds from the sale or disposition of engines, and all insurance proceeds. We have not guaranteed any obligations of WEST II and no assets outside of the WEST II trust secure such obligations.

We are the servicer and administrative agent for WEST II. Our annual fees for these services are 11.5% as servicer and 2.0% as administrative agent of the aggregate net rents actually received by WEST II on its engines, and such fees are payable to us monthly. We are also paid a fee of 3.0% of the net proceeds from the sale of any engines. As WEST II is consolidated in our financial statements these fees eliminate in consolidation. Proceeds from engine sales will be used, at WEST II’s election, to reduce WEST II’s debt or to acquire other engines.

WEST II gives us the flexibility to manage the portfolio to adapt to changes in aircraft fleets and customer demand over time, benefiting both us and our investors. The asset-backed securitization is well suited to our engine leasing business as it provides long term capital in which debt maturity is better matched to our long term asset lives.

INDUSTRY BACKGROUND - THE DEMAND FOR LEASED AIRCRAFT ENGINES

Historically, commercial aircraft operators owned rather than leased their spare engines. As engines become more powerful and technically sophisticated, they also become more expensive to acquire and maintain. In part due to cash constraints on commercial aircraft operators and the costs associated with engine ownership, commercial aircraft operators have become more cost-conscious and now utilize operating leases for a portion of their spare engines and are therefore better able to manage their finances in this capital-intensive business. Engine leasing is a specialized business that has evolved into a discrete sector of the commercial aviation market. Participants in this sector need access to capital, as well as specialized technical knowledge, in order to compete successfully.

Growth in the spare engine leasing industry is dependent on two fundamental drivers:

We believe both drivers will increase over time.

Increased number of aircraft, and therefore engines, in the market

We believe that the number of commercial and cargo aircraft, and hence spare engines, will increase. Boeing estimates that there are roughly 23,000 aircraft as of 2015 and projects this will grow to approximately 45,000 aircraft by 2035. Aircraft equipment manufacturers have predicted such an increase in aircraft to address the rapid growth of both passenger and cargo traffic in the Asian markets, as well as demand for new aircraft in more mature markets.

Increased lease penetration rate

Spare engines provide support for installed engines in the event of routine or other engine maintenance or unscheduled removal. The number of spare engines needed to service any fleet is determined by many factors. These factors include:

We believe that commercial aircraft operators are increasingly considering their spare engines as significant capital assets, where operating leases may be more attractive than capital leases or ownership of spare engines. Some believe that currently as many as 35% to 40% of the spare engine market falls under the category of leased engines. Industry analysts have forecast that the percentage of leased engines is likely to increase over the next 15 years as engine leasing follows the growth of aircraft leasing. We believe this is due to the increasing cost of newer engines, the anticipated modernization of the worldwide aircraft fleet and the significant cost associated therewith, and the emergence of new niche-focused airlines which generally use leasing in order to obtain their capital assets.

ENGINE LEASING

As of December 31, 2016, all of our leases to air carriers, manufacturers and MROs are operating leases as opposed to finance leases. Under operating leases, we retain the potential benefit and assume the risk of the residual value of the aircraft equipment, in contrast to capital or financing leases where the lessee has more of the potential benefits and risks of ownership. Operating leases allow commercial aircraft operators greater fleet and financial flexibility due to the relatively small initial capital outlay necessary to obtain use of the aircraft equipment, and the availability of short and long term leases to better meet their needs. Operating lease rates are generally higher than finance lease rates, in part because of the risks associated with the residual value.

We describe all of our current leases as “triple-net” operating leases. A triple-net operating lease requires the lessee to make the full lease payment and pay any other expenses associated with the use of the engines, such as maintenance, casualty and liability insurance, sales or use taxes and personal property taxes. The leases contain detailed provisions specifying the lessees’ responsibility for engine damage, maintenance standards and the required condition of

the engine upon return at the end of the lease. During the term of the lease, we generally require the lessee to maintain the engine in accordance with an approved maintenance program designed to meet applicable regulatory requirements in the jurisdictions in which the lessee operates.

We try to mitigate risk where possible. For example, we make an analysis of the credit risk associated with the lessee before entering into any significant lease transaction. Our credit analysis generally consists of evaluating the prospective lessee’s financial standing by utilizing financial statements and trade and/or banking references. In certain circumstances, we may require our lessees to provide additional credit support such as a letter of credit or a guaranty from a bank or a third party or a security deposit. We also evaluate insurance and expropriation risk and evaluate and monitor the political and legal climate of the country in which a particular lessee is located in order to determine our ability to repossess our engines should the need arise. Despite these guidelines, we cannot give assurance that we will not experience collection problems or significant losses in the future. See “Risk Factors” below.

At the commencement of a lease, we may collect, in advance, a security deposit normally equal to at least one month’s lease payment. The security deposit is returned to the lessee after all lease return conditions have been met. Under the terms of some of our leases, during the term of the lease, the lessees pay amounts to us based on usage of the engine, which is referred to as maintenance reserves or use fees, which are designed to cover the expected future maintenance costs. For those leases in which the maintenance reserves are reimbursable to the lessee, maintenance reserves are collected and are reimbursed to the lessee when qualifying maintenance is performed. Under longer-term leases, to the extent that cumulative use fee billings are inadequate to fund expenditures required prior to return of the engine to us, the lessee is obligated to cover the shortfall. Recovery is therefore dependent upon the financial condition of the lessee.

During the lease period, our leases require that maintenance and inspection of the leased engines be performed at qualified maintenance facilities certified by the FAA or its foreign equivalent. In addition, when an engine becomes off-lease, it undergoes inspection to verify compliance with lease return conditions. Our management believes that our attention to our lessees and our emphasis on maintenance and inspection helps preserve residual values and generally helps us to recover our investment in our leased engines.

Upon termination of a lease, we will lease, sell or part out the related engines. The demand for aftermarket engines for either sale or lease may be affected by a number of variables, including:

The value of particular used engines varies greatly depending upon their condition, the maintenance services performed during the lease term and, as applicable, the number of hours or cycles remaining until the next major maintenance is required. If we are unable to lease or sell engines on favorable terms, our financial results and our ability to service debt may be adversely affected. See “Risk Factors” below.

The value of a particular model of engine is heavily dependent on the status of the types of aircraft on which it is installed. We believe values of engines tend to be stable so long as the host aircraft for the engines as well as the engines themselves are still being manufactured. Prices will also tend to remain stable and even rise after a host aircraft is no longer manufactured so long as there is sufficient demand for the host aircraft. However, the value of an engine

begins to decline rapidly once the host aircraft begins to be retired from service and/or parted out in significant numbers. Values of engines also may decline because of manufacturing defects that may surface subsequently.

As of December 31, 2016, we had a total lease portfolio of 208 aircraft engines and related equipment, 5 spare parts packages, 11 aircraft and various parts and other engine-related equipment with a net book value of $1,136.6 million in our lease portfolio.  As of December 31, 2015, we had a total lease portfolio of 201 aircraft engines and related equipment, 5 spare parts packages, 10 aircraft and various parts and other engine-related equipment with a net book value of $1,109.2 million in our lease portfolio.

As of December 31, 2016, minimum future rentals under non-cancelable operating leases of these engines, parts and aircraft assets were as follows:

As of December 31, 2016, we had 80 lessees of commercial aircraft engines, aircraft, and other aircraft-related equipment in 43 countries. We believe the loss of any one customer would not have a significant long-term adverse effect on our business.  We operate in a global market in which our engines are easily transferable among lessees located in many countries, which stabilizes demand and allows us to recover from the loss of a particular customer. As a result, we do not believe we are dependent on a single customer or a few customers, the loss of which would have a material adverse effect on our revenues.

On May 25, 2011, we entered into an agreement with Mitsui & Co., Ltd. to participate in a joint venture formed as a Dublin-based Irish limited company — Willis Mitsui & Company Engine Support Limited (“WMES”) for the purpose of acquiring and leasing jet engines. Each partner holds a fifty percent interest in the joint venture. Our investment in the joint venture is $32.5 million as of December 31, 2016.

On June 3, 2014 we entered into an agreement with China Aviation Supplies Import & Export Corporation (“CASC”) to participate in a joint venture named CASC Willis Engine Lease Company Limited (“CASC Willis”), a new joint venture based in Shanghai, China. Each partner holds a fifty percent interest in the joint venture.    In October 2014, we made a $15.0 million initial capital contribution, representing our fifty percent, up-front funding contribution to the new joint venture. The company acquires and leases jet engines to Chinese airlines and concentrates on meeting the fast growing demand for leased commercial aircraft engines and aviation assets in the People’s Republic of China. CASC Willis owned a lease portfolio of 3 engines with a net book value of $49.1 million as of December 31, 2016. Our investment in the joint venture is $12.9 million as of December 31, 2016. During 2016, CASC was reorganized, with portions of its partnership interest in CASC Willis being transferred to three Chinese airlines and another government-owned entity.  The 2016 CASC reorganization resulted in no voting structure change to the joint venture.

AIRCRAFT LEASING

As of December 31, 2016, we owned and leased four Boeing 737 aircraft, four ATR72-202 turboprop, two Embraer E-190LR, and one Bombardier Challenger aircraft with an aggregate net book value of $105.7 million.

Our aircraft leases are “triple-net” leases and the lessee is responsible for making the full lease payment and paying any other expenses associated with the use of the aircraft, such as maintenance, casualty and liability insurance, sales or use taxes and personal property taxes. In addition, the lessee is responsible for normal maintenance and repairs, engine and airframe overhauls, and compliance with return conditions of flight equipment on lease. Under the provisions of many leases, for certain engine and airframe overhauls, we reimburse the lessee for costs incurred up to but not  

exceeding maintenance reserves the lessee has paid to us. Maintenance reserves are designed to cover the expected maintenance costs. The lessee is also responsible for compliance with all applicable laws and regulations with respect to the aircraft. We require our lessees to comply with FAA requirements. We periodically inspect our leased aircraft. Generally, we require a deposit as security for the lessee’s performance of obligations under the lease and the condition of the aircraft upon return. In addition, the leases contain extensive provisions regarding our remedies and rights in the event of a default by the lessee and specific provisions regarding the condition of the aircraft upon return. The lessee is required to continue to make lease payments under all circumstances, including periods during which the aircraft is not in operation due to maintenance or grounding.

SPARE PARTS SALES

The sale of spare parts is managed by the Company’s wholly owned subsidiary, Willis Aero. Willis Aero primarily engages in the sale of aircraft engine parts and materials through the acquisition or consignment from third parties of aircraft and engines. The launch of this new business segment in November 2013 positioned our Company to provide end-of-life solutions for the growing supply of surplus aircraft and engines. With the establishment of Willis Aero, we are able to manage the full lifecycle of our lease assets, enhance the returns on our engine portfolio and create incremental value for our shareholders.  As of December 31, 2016, spare parts inventory had a carrying value of $25.4 million.

WILLIS ASSET MANAGEMENT LIMITED

In 2016, Willis Asset Management Limited (“Willis Asset Management”), a newly formed Welsh subsidiary, purchased the business and assets of TES, the consulting and asset management business of the TES Aviation Group.  Willis Asset Management is an asset management, technical services and consultancy business.  Willis Asset Management has 502 engines under management as of December 31, 2016.

OUR COMPETITIVE ADVANTAGES

We are uniquely positioned in the market and remain competitive, in part, due to the following advantages:

COMPETITION

The markets for our products and services are very competitive, and we face competition from a number of sources. These competitors include aircraft engine and aircraft parts manufacturers, aircraft and aircraft engine lessors, airline and aircraft service and repair companies and aircraft and aircraft engine spare parts distributors. Many of our competitors have substantially greater resources than us. Those resources may include greater name recognition, larger product lines, complementary lines of business, greater financial, marketing, information systems and other resources. In addition, equipment manufacturers, aircraft maintenance providers, FAA certified repair facilities and other aviation aftermarket suppliers may vertically integrate into the markets that we serve, thereby significantly increasing industry competition. We can give no assurance that competitive pressures will not materially and adversely affect our business, financial condition or results of operations.

We compete primarily with aircraft engine manufacturers as well as with other aircraft engine lessors. It is common for commercial aircraft operators and MROs to utilize several leasing companies to meet their aircraft engine needs and to minimize reliance on a single leasing company.

Our competitors compete with us in many ways, including pricing, technical expertise, lease flexibility, engine availability, supply reliability, customer service and the quality and condition of engines. Some of our competitors have greater financial resources than we do, or are affiliates of larger companies. We emphasize the quality of our portfolio of aircraft engines, supply reliability and high level of customer service to our aircraft equipment lessees. We focus on ensuring adequate aircraft engine availability in high-demand locations, dedicate large portions of our organization to building relationships with lessees, maintain close day-to-day coordination with lessees and have developed an engine pooling arrangement that allows pool members quick access to available spare aircraft engines.

INSURANCE

In addition to requiring full indemnification under the terms of our leases, we require our lessees to carry the types of insurance customary in the air transportation industry, including comprehensive third party liability insurance and physical damage and casualty insurance. We require that we be named as an additional insured on liability insurance with ourselves and our lenders normally identified as the loss payee for damage to the equipment on policies carried by lessees. We monitor compliance with the insurance provisions of the leases. We also carry contingent physical damage and third party liability insurance as well as product liability insurance.

GOVERNMENT REGULATION

Our customers are subject to a high degree of regulation in the jurisdictions in which they operate. For example, the FAA regulates the manufacture, repair and operation of all aircraft operated in the United States and equivalent regulatory agencies in other countries, such as the European Aviation Safety Agency (“EASA”) in Europe, regulate aircraft operated in those countries. Such regulations also indirectly affect our business operations. All aircraft operated in the United States must be maintained under a continuous condition-monitoring program and must periodically undergo thorough inspection and maintenance. The inspection, maintenance and repair procedures for commercial aircraft are prescribed by regulatory authorities and can be performed only by certified repair facilities utilizing certified technicians. The FAA can suspend or revoke the authority of air carriers or their licensed personnel for failure to comply with regulations and ground aircraft if their airworthiness is in question.

While our leasing and reselling business is not regulated, the aircraft, engines and related parts that we purchase, lease and sell must be accompanied by documentation that enables the customer to comply with applicable regulatory requirements. Furthermore, before parts may be installed in an aircraft, they must meet certain standards of condition established by the FAA and/or the equivalent regulatory agencies in other countries. Specific regulations vary from country to country, although regulatory requirements in other countries are generally satisfied by compliance with FAA requirements. With respect to a particular engine or engine component, we utilize FAA and/or EASA certified repair stations to repair and certify engines and components to ensure marketability.

Effective January 1, 2000, federal regulations stipulate that all aircraft engines hold, or be capable of holding, a noise certificate issued under Chapter 3 of Volume 1, Part II of Annex 16 of the Chicago Convention, or have been shown to comply with Stage III noise levels set out in Section 36.5 of Appendix C of Part 36 of the FAA Regulations of the United States if the engines are to be used in the continental United States. Additionally, much of Europe has adopted similar regulations. As of December 31, 2016, all of the engines in our lease portfolio are Stage III engines and are generally suitable for use on one or more commonly used aircraft.

We believe that the aviation industry will be subject to continued regulatory activity. Additionally, increased oversight will continue to originate from the quality assurance departments of airline operators. We have been able to meet all such requirements to date, and believe that we will be able to meet any additional requirements that may be imposed. We cannot give assurance, however, that new, more stringent government regulations will not be adopted in the future or that any such new regulations, if enacted, would not have a material adverse impact on us.

GEOGRAPHIC AREAS IN WHICH WE OPERATE

At December 31, 2016, approximately 86% of our on-lease engines, related aircraft parts, and equipment (all of which we sometimes refer to as “equipment”) by net book value are leased and operated internationally. All leases relating to this equipment are denominated and payable in U.S. dollars, which is customary in the industry. Future leases may provide for payments to be made in euros or other foreign currencies. In 2016, we leased our equipment to lessees domiciled in eight geographic regions. We are subject to a number of risks related to our foreign operations. See “Risk Factors” below.

The following table displays the regional profile of our lease customer base for the years ended December 31, 2016, 2015 and 2014.  The United States and China each accounted for more than 10% of our lease rent revenue in 2016.  No country accounted for more than 10% of our lease rent revenue in 2015.  The United States accounted for more than

10% of our lease rent revenue in 2014. The tables include geographic information about our leased equipment grouped by the lessee’s domicile (which does not necessarily indicate the asset’s actual location):

FINANCING/SOURCE OF FUNDS

We, directly or through WEST II, typically acquire engines with a combination of equity capital and funds borrowed from financial institutions. In order to facilitate financing and leasing of engines, each engine is generally owned through a statutory or common law trust that is wholly-owned by us or our subsidiaries. We usually borrow 85% of an engine purchase price. Substantially all of our assets secure our related indebtedness. We typically acquire engines from airlines in a sale-lease back transaction, from engine manufacturers or from other lessors. From time to time, we selectively acquire engines prior to a firm commitment to lease or sell the engine, depending on the price of the engine and market demand with the expectation that we can lease or sell such engines in the future.

EMPLOYEES

As of December 31, 2016, we had 147 full-time employees (excluding consultants), in sales and marketing, technical service and administration. None of our employees are covered by a collective bargaining agreement and we believe our employee relations are satisfactory.

ITEM 1A.RISK FACTORS

The following risk factors and other information included in this Annual Report should be carefully considered. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations. If any of the following risks occur, our business, financial condition, operating results and cash flows could be materially and adversely affected.

RISKS RELATING TO OUR BUSINESS

We are affected by the risks faced by commercial aircraft operators and maintenance, repair and overhaul companies (“MROs”) because they are our customers.

Commercial aircraft operators are engaged in economically sensitive, highly cyclical and competitive businesses. We are a supplier to commercial aircraft operators and MROs. As a result, we are indirectly affected by all the risks facing commercial aircraft operators and MROs, that are beyond our control. Our results of operations depend, in part, on the financial strength of our customers and our customers’ ability to compete effectively in the marketplace and manage their risks. These risks include, among others:

To the extent that our customers are negatively affected by these risk factors, we may experience:

Our engine values and lease rates, which are dependent on the status of the types of aircraft on which engines are installed, and other factors, could decline.

The value of a particular model of engine depends heavily on the types of aircraft on which it may be installed and the supply of available engines. We believe values of engines tend to be relatively stable so long as there is sufficient demand for the host aircraft. However, we believe the value of an engine begins to decline rapidly once the host aircraft begins to be retired from service and/or used for spare parts in significant numbers. Certain types of engines may be used in significant numbers by commercial aircraft operators that are currently experiencing financial difficulties. If such operators were to go into liquidation or similar proceedings, the resulting over-supply of engines from these operators could have an adverse effect on the demand for the affected engine types and the values of such engines.

Upon termination of a lease, we may be unable to enter into new leases or sell the engine or its parts on acceptable terms.

We own the engines that we lease to customers and bear the risk of not recovering our entire investment through leasing and selling the engines. Upon termination of a lease, we seek to enter a new lease or to sell or part-out the engine. We also selectively sell engines on an opportunistic basis. We cannot give assurance that we will be able to find, in a timely manner, a lessee or a buyer for our engines coming off-lease or for their associated parts. If we do find a lessee, we may not be able to obtain satisfactory lease rates and terms (including maintenance and redelivery conditions) or rates and terms comparable to our current leases, and we can give no assurance that the creditworthiness of any future lessee will be equal to or better than that of the existing lessees of our engines. Because the terms of engine leases may be less than 12 months, we may frequently need to remarket engines. We face the risk that we may not be able to keep our engines on lease consistently.

We are subject to the risks and costs of aircraft maintenance and obsolescence on the aircraft that we own.

We currently own and lease four Boeing 737 aircraft, four ATR72-202 turboprop, two E-190LR aircraft and one Bombardier Challenger aircraft. We may buy other aircraft or interests in aircraft in the future primarily to seek opportunities to realize value from the engines or related parts. Among other risks described in this Annual Report, the following risks apply when we lease or sell aircraft:

We carry the risk of maintenance for our leased assets. Our maintenance reserves may be inadequate or lessees may default on their obligations to perform maintenance, which could increase our expenses.

Under most of our engine and aircraft leases, the lessee makes monthly maintenance reserve payments to us based on the asset’s usage and management’s estimate of maintenance costs. A certain level of maintenance reserve payments on the WEST II engines are held in related engine reserve restricted cash accounts. Generally, the lessee under long term leases is responsible for all scheduled maintenance costs, even if they exceed the amounts of maintenance reserves paid. Forty-nine of our leases comprising approximately 25.3% of the net book value of our on-lease assets at December 31, 2016 do not provide for any monthly maintenance reserve payments to be made by lessees, and we can give no assurance that future leases of our engines will require maintenance reserves. In some cases, including engine and aircraft repossessions, we may decide to pay for refurbishments or repairs if the accumulated use fees are inadequate.

We can give no assurance that our operating cash flows and available liquidity reserves, including the amounts held in the engine reserve restricted cash accounts, will be sufficient to fund necessary engine maintenance. Actual maintenance reserve payments by lessees and other cash that we receive may be significantly less than projected as a result of numerous factors, including defaults by lessees. Furthermore, we can provide no assurance that lessees will meet their obligations to make maintenance reserve payments or perform required scheduled maintenance or, to the extent that maintenance reserve payments are insufficient, to cover the cost of refurbishments or repairs.

Failures by lessees to meet their maintenance and recordkeeping obligations under our leases could adversely affect the value of our leased engines and aircraft and our ability to lease the engines and aircraft in a timely manner following termination of the leases.

The value and income producing potential of an engine or aircraft depends heavily on it being maintained in accordance with an approved maintenance system and complying with all applicable governmental directives and manufacturer requirements. In addition, for an engine or aircraft to be available for service, all records, logs, licenses and documentation relating to maintenance and operations of the engine or aircraft must be maintained in accordance with governmental and manufacturer specifications.

Our leases make the lessees primarily responsible for maintaining the engines or aircraft, keeping related records and complying with governmental directives and manufacturer requirements. Over time, certain lessees have experienced, and may experience in the future, difficulties in meeting their maintenance and recordkeeping obligations as specified by the terms of our leases.

Our ability to determine the condition of the engines or aircraft and whether the lessees are properly maintaining our assets is generally limited to the lessees’ reporting of monthly usage and any maintenance performed, confirmed by periodic inspections performed by us and third-parties. A lessee’s failure to meet its maintenance or recordkeeping obligations under a lease could result in:

Any of these events may adversely affect the value of the engine, unless and until remedied, and reduce our revenues and increase our expenses. If an engine is damaged during a lease and we are unable to recover from the lessee or though insurance, we may incur a loss.

Our operating results vary and comparisons to results for preceding periods may not be meaningful.

Due to a number of factors, including the risks described in this ITEM 1A, our operating results may fluctuate. These fluctuations may also be caused by:

These risks may reduce our engine utilization rates, lease margins, maintenance reserve revenues and proceeds from engine sales, and result in higher legal, technical, maintenance, storage and insurance costs related to repossession and the cost of engines being off-lease. As a result of the foregoing and other factors, the availability of engines for lease or sale periodically experiences cycles of oversupply and undersupply of given engine models. The incidence of an oversupply of engines may produce substantial decreases in engine lease rates and the appraised and resale value of engines and may increase the time and costs incurred to lease or sell engines.

We anticipate that fluctuations from period to period will continue in the future. As a result, we believe that comparisons to results for preceding periods may not be meaningful and that results of prior periods should not be relied upon as an indication of our future performance.

Our customers face intense competition and some carriers are in troubled financial condition.

Certain lessees may be significantly delinquent in their rental payments and may default on their lease obligations. As of December 31, 2016, we had an aggregate of approximately $3.6 million in lease rent and $2.4 million in maintenance reserve payments more than 30 days past due. Our inability to collect receivables or to repossess engines, aircraft or other leased equipment in the event of a default by a lessee could have a material adverse effect on us.

Following the September 11, 2001 terrorist attacks and the global recession that began in 2008, the commercial aviation industry was negatively affected.  The airline industry recovered in the years thereafter and has returned to profitability with some carriers even posting record profits. However, we cannot give assurance that delinquencies and defaults on our leases will not increase during future cyclical downturns in the economy and commercial aviation industry.

Various airlines have filed for bankruptcy in the United States and in foreign jurisdictions, with some seeking to restructure their operations and others ceasing operations entirely. In the case of airlines that are restructuring, such airlines often reduce their flights or eliminate the use of certain types of aircraft and the related engine types. Applicable bankruptcy laws often allow these airlines to terminate leases early and to return our engines or aircraft without meeting the contractual return conditions. In that case, we may not be paid the full amount, or any part, of our claims for these lease terminations. Alternatively, we might negotiate agreements with those airlines under which the airline continues to lease the engine or aircraft, but under modified lease terms.  In the case of an airline which has ceased operations entirely, in addition to the risk of nonpayment, we face the enhanced risk of deterioration or total loss of an engine or aircraft while it is under uncertain custody and control.  In that case, we may be required to take legal action to secure the return of the engine or aircraft and its records or, alternatively, to negotiate a settlement under which we can immediately recover the engine or aircraft and its records in exchange for waiving subsequent legal claims.

We may not be able to repossess an engine or aircraft when the lessee defaults, and even if we are able to repossess the engine or aircraft, we may have to expend significant funds in the repossession, remarketing and leasing of the asset.

When a lessee defaults and such default is not cured in a timely manner we typically seek to terminate the lease and repossess the engine or aircraft. If a defaulting lessee contests the termination and repossession or is under court protection, enforcement of our rights under the lease may be difficult, expensive and time-consuming. We may not realize any practical benefits from our legal rights and we may need to obtain consents to export the engine or aircraft. As a result, the relevant asset may be off-lease or not producing revenue for a prolonged period. In addition, we will

incur direct costs associated with repossessing our engine or aircraft. These costs may include legal and similar costs, the direct costs of transporting, storing and insuring the engine or aircraft, and costs associated with necessary maintenance and recordkeeping to make the asset available for lease or sale. During this time, we will realize no revenue from the leased engine or aircraft, and we will continue to be obligated to pay our debt financing for the asset. If an engine is installed on an airframe, the airframe may be owned by an aircraft lessor or other third party. Our ability to recover engines installed on airframes may depend on the cooperation of the airframe owner.

We and our customers operate in a highly regulated industry and changes in laws or regulations may adversely affect our ability to lease or sell our engines or aircraft.

Licenses and consents

We and our customers operate in a highly regulated industry. A number of our leases require specific governmental or regulatory licenses, consents or approvals. These include consents for certain payments under the leases and for the export, import or re-export of our engines or aicraft. Consents needed in connection with future leasing or sale of our engines or aircraft may not be received timely or have economically feasible terms. Any of these events could adversely affect our ability to lease or sell engines or aircraft.

The U.S. Department of Commerce, or the “Commerce Department,” regulates exports. We are subject to the Commerce Department’s and the U.S. Department of State’s regulations with respect to the lease and sale of engines and aircraft to foreign entities and the export of related parts. These Departments may, in some cases, require us to obtain export licenses for engines exported to foreign countries. The U.S. Department of Homeland Security, through the U.S. Customs and Border Protection, enforces regulations related to the import of engines and aircraft into the United States for maintenance or lease and imports of parts for installation on our engines and aircraft.

We are prohibited from doing business with persons designated by the U.S. Department of the Treasury’s Office of Foreign Assets Control, or “OFAC,” on its “Specially Designated Nationals List,” and must monitor our operations and existing and potential lessees for compliance with OFAC’s rules.  Similarly, sanctions issued by the United Nations, the U.S. government, the European Union or other governments could prohibit or restrict us from doing business in certain countries or with certain persons, and we must monitor our operations and existing and potential lessees for compliance with such sanctions.

Anti-corruption Laws

As a U.S. corporation with significant international operations, we are required to comply with a number of U.S. and international laws and regulations, including those combating corruption.  For example, the U.S. Foreign Corrupt Practices Act (the "FCPA") and similar world-wide anti-bribery laws generally prohibit improper payments to foreign officials for the purpose of influencing any official act or decision or securing any improper advantage. The scope and enforcement of anti-corruption laws and regulations may vary. Although our policies expressly mandate compliance with the FCPA and similarly applicable laws, there can be no assurance that none of our employees or agents will take any action in violation of our policies. Violations of such laws or regulations could result in substantial civil or criminal fines or sanctions. Actual or alleged violations could also damage our reputation, be expensive to defend, and impair our ability to do business.

Civil aviation regulation

Users of engines and aircraft are subject to general civil aviation authorities, including the FAA and the EASA, who regulate the maintenance of engines and issue airworthiness directives. Airworthiness directives typically set forth special maintenance actions or modifications to certain engine and aircraft types or series of specific engines that must be implemented for the engine or aircraft to remain in service. Also, airworthiness directives may require the lessee to make more frequent inspections of an engine, aircraft or particular engine parts. Each lessee of an engine or aircraft generally is responsible for complying with all airworthiness directives. However, if the engine or aircraft is off lease, we may be forced to bear the cost of compliance with such airworthiness directives, and if the engine or aircraft is leased, subject to the terms of the lease, if any, we may be forced to share the cost of compliance.

Environmental regulation

Governmental regulations of noise and emissions levels may be applicable where the related airframe is registered, and where the aircraft is operated. For example, jurisdictions throughout the world have adopted noise regulations which require all aircraft to comply with Stage III noise requirements. In addition to the current Stage III compliance requirements, the United States and the International Civil Aviation Organization, or “ICAO,” have adopted a more stringent set of “Stage IV” standards for noise levels which apply to engines manufactured or certified from 2006 onward. At this time, the United States regulations do not require any phase-out of aircraft that qualify only for Stage III compliance, but the European Union has established a framework for the imposition of operating limitations on non-Stage IV aircraft. These regulations could limit the economic life of our engines and aircraft or reduce their value, could limit our ability to lease or sell the non-compliant engines or aircraft or, if modifications are permitted, require us to make significant additional investments in the engines or aircraft to make them compliant.

The United States and other jurisdictions are imposing more stringent limits on the emission of nitrogen oxide, carbon monoxide and carbon dioxide emissions from engines, consistent with ICAO standards. These limits generally apply only to engines manufactured after 1999. In 2005, the European Union launched an Emissions Trading System limiting greenhouse gas emissions by various industries and persons, including aircraft operators.  Concerns over global warming could result in more stringent limitations on the operation of older, non-compliant engines and aircraft.

Any change to current tax laws or accounting principles making operating lease financing less attractive could adversely affect our business, financial condition and results of operations.

Our lessees enjoy favorable accounting and tax treatment by using operating leases. Changes in tax laws or accounting principles that make operating leases less attractive to our lessees could have a material adverse effect on demand for our leases and on our business.

Our consolidated financial statements are prepared in accordance with GAAP.  If there are future changes in GAAP with regard to how we and our customers must account for leases, it could change the way we and our customers conduct our businesses and, therefore, could have the potential to have an adverse effect on our business.

In February 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update No. 2016-02, “Leases” (topic 842). The FASB issued this update to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The updated guidance is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of the update is permitted. The Company is evaluating the impact of the adoption of this update on our consolidated financial statements and related disclosures.

Our aircraft, engines or parts could cause bodily injury or property damage, exposing us to liability claims.

We are exposed to potential liability claims if the use of our aircraft, engines or parts is alleged to have caused bodily injury or property damage. Our leases require our lessees to indemnify us against these claims and to carry insurance customary in the air transportation industry, including liability, property damage and hull all risks insurance on our engines and on our aircraft at agreed upon levels. We can give no assurance that one or more catastrophic events will not exceed insurance coverage limits or that lessees’ insurance will cover all claims that may be asserted against us. Any insurance coverage deficiency or default by lessees under their indemnification or insurance obligations may reduce our recovery of losses upon an event of loss.

We may not be adequately covered by insurance.

While we maintain contingent insurance covering losses not covered by our lessees’ insurance, such coverage may not be available in circumstances where the lessees’ insurance coverage is insufficient. In addition, if a lessee is not obligated to maintain sufficient insurance, we may incur the costs of additional insurance coverage during the related lease. We are required under certain of our debt facilities to obtain political risk insurance for leases to lessees in specified jurisdictions. We can give no assurance that such insurance will be available at commercially reasonable rates, if at all.

Currently, the U.S. government is still offering war risk insurance to U.S.-certificated airlines; however, most foreign governments have ceased this practice, forcing non-U.S. airlines back into the commercial insurance market for this coverage. It is unknown how long the U.S. government will continue to offer war risk insurance and whether U.S.-certificated airlines could obtain war risk insurance in the commercial markets on acceptable terms and conditions.

We and our lenders generally are named as an additional insureds on liability insurance policies carried by our lessees and are usually the loss payees for damage to our engines and aircraft. We have not experienced any significant aviation-related claims or any product liability claims related to our engines, aircraft or spare parts that were not insured. However, an uninsured or partially insured claim, or a claim for which third-party indemnification is not available, could have a material adverse effect upon us. A loss of an aircraft where we lease the airframe, an engine or spare parts could result in significant monetary claims for which there may not be sufficient insurance coverage.

RISKS RELATING TO OUR CAPITAL STRUCTURE

Our inability to obtain sufficient capital would constrain our ability to grow our portfolio and to increase our revenues.

Our business is capital intensive and highly leveraged. Accordingly, our ability to successfully execute our business strategy and maintain our operations depends on the availability and cost of debt and equity capital. Additionally, our ability to borrow against our portfolio of engines and aircraft is dependent, in part, on the appraised value of our engines and aircraft. If the appraised value of our engines and aircraft declines, we may be required to reduce the principal outstanding under certain of our debt facilities. Availability under such debt facilities may also be reduced, at least temporarily, as a result of such reduced appraisals.

The relatively recent, well-publicized, worldwide disruptions in the credit and financial markets increase the risk of adverse effects on our customers and our capital providers (lenders and derivative counter-parties) and therefore on us. The disruptions may also adversely affect our ability to raise additional capital to fund our continued growth. Although we have adequate debt commitments from our lenders, assuming they are willing and able to meet their contractual obligation to lend to us, market disruptions may adversely affect our ability to raise additional equity capital to fund future growth, requiring us to rely on internally generated funds. This would lower our rate of capital investment.

We can give no assurance that the capital we need will be available to us on favorable terms, or at all. Our inability to obtain sufficient capital, or to renew or expand our credit facilities, could result in increased funding costs and would limit our ability to:

Our financing facilities impose restrictions on our operations.

We have, and expect to continue to have, various credit and financing arrangements with third parties. These financing arrangements are secured by all or substantially all of our assets. Our existing credit and financing arrangements require us to meet certain financial condition tests. Our revolving credit facility prohibits our declaring or paying dividends on shares of any class or series of our common or preferred stock if an event of default under such facility has or will occur and remains uncured. The agreements governing our debt, including the issuance of notes by WEST II, also include restrictive financial covenants. A breach of those and other covenants could, unless waived or amended by our creditors, result in a cross-default to other indebtedness and an acceleration of all or substantially all of our debt. We have obtained such waivers and amendments to our financing agreements in the past, but we cannot provide any assurance that we will receive such waivers or amendments in the future if we require them. If our outstanding debt is accelerated at any time, we likely would have little or no cash or other assets available after payment

of our debts, which could cause the value or market price of our outstanding equity securities to decline significantly and we would have few, if any, assets available for distributions to our equity holders in liquidation.

We are exposed to interest rate risk on our leases, which could have a negative impact on our margins.

We are affected by fluctuations in interest rates. Our lease rates are generally fixed, and a portion of our debt bears variable rate interest based on one-month LIBOR, so changes in interest rates directly affect our lease margins. From time to time, we seek to reduce our interest rate volatility and uncertainty through hedging with interest rate derivative contracts with respect to a portion of our debt. Our lease margins, as well as our earnings and cash flows may be adversely affected by increases in interest rates, to the extent we do not have hedges or other derivatives in place or if our hedges or other derivatives do not mitigate our interest rate exposure from an economic standpoint. We would be adversely affected by increasing interest rates. As reported by British Bankers’ Association, the one-month LIBOR was approximately 0.77% and 0.43% on December 31, 2016 and December 31, 2015, respectively.

An increase in interest rates or in our borrowing margin would increase the cost of servicing our debt and could reduce our profitability.

A significant portion of our outstanding debt bears interest at floating rates. As a result, to the extent we have not hedged against rising interest rates, an increase in the applicable benchmark interest rates would increase our cost of servicing our debt and could materially adversely affect our results of operations, financial condition, liquidity and cash flows.

In addition, we regularly refinance our indebtedness. If interest rates or our borrowing margins increase between the time an existing financing arrangement was consummated and the time such financing arrangement is refinanced, the cost of servicing our debt would increase and our results of operations, financial condition, liquidity and cash flows could be materially adversely affected.

We have risks in managing our portfolio of engines to meet customer needs.

The relatively long life cycles of aircraft and jet engines can be shortened by world events, government regulation or customer preferences. We seek to manage these risks by trying to anticipate demand for particular engine and aircraft types, maintaining a portfolio mix of engines that we believe is diversified and that will have long-term value and will be sought by lessees in the global market for jet engines, and by selling engines and aircraft that we expect will experience obsolescence or declining usefulness in the foreseeable future. The WEST II securitization facility includes restrictions and limitations on the sale of engines in that facility including, among others, that (i) the net proceeds from any individual engine sale must be at least 105% of the debt allocated under the facility to that engine, and (ii) the aggregate appraised value of the facility’s engines sold through September 2019 cannot exceed 20% of the total appraised value of the facility’s engines at the inception of the facility plus the value of capitalized modifications to the engines since then, and cannot exceed 30% thereafter.  We can give no assurance that we can successfully manage our engine portfolio to reduce these risks.

Our inability to maintain sufficient liquidity could limit our operational flexibility and also impact our ability to make payments on our obligations as they come due.

In addition to being capital intensive and highly leveraged, our business also requires that we maintain sufficient liquidity to enable us to contribute the non-financed portion of engine and aircraft purchases as well as to service our payment obligations to our creditors as they become due, despite the fact that the timing and amounts of payments under our leases do not match the timing under our debt service obligations. Our restricted cash is unavailable for general corporate purposes. Accordingly, our ability to successfully execute our business strategy and maintain our operations depends on our ability to continue to maintain sufficient liquidity, cash and available credit under our credit facilities. Our liquidity could be adversely impacted if we are subjected to one or more of the following: a significant decline in lease revenues, a material increase in interest expense that is not matched by a corresponding increase in lease rates, a significant increase in operating expenses, or a reduction in our available credit under our credit facilities. If we do not maintain sufficient liquidity, our ability to meet our payment obligations to creditors or to borrow additional funds could become impaired as could our ability to make dividend payments or other distributions to our equity holders. See

“Management’s Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources.”

NUMEROUS FACTORS MAY AFFECT THE TRADING PRICE OF OUR COMMON STOCK

The trading price of our common stock may fluctuate due to many factors, including:

In addition, the U.S. stock markets have experienced price and volume volatility that has affected many companies’ stock prices, often for reasons unrelated to the operating performance of those companies.

RISKS RELATING TO OUR FOREIGN OPERATIONS

A substantial portion of our lease revenue comes from foreign customers, subjecting us to divergent regulatory requirements.

For the year ended December 31, 2016, 89% of our lease revenue was generated by leases to foreign customers. Such international leases present risks to us because certain foreign laws, regulations and judicial procedures may not be as protective of lessor rights as those which apply in the United States. We are also subject to risks of foreign laws that affect the timing and access to courts and may limit our remedies when collecting lease payments and recovering assets. None of our leased engines have been expropriated; however, we can give no assurance that political instability abroad and changes in the policies of foreign nations will not present expropriation risks in the future that are not covered by insurance.

A substantial portion of our leases require payments in U.S. dollars but many of our customers operate in other currencies; if foreign currencies devalue against the U.S. dollar, our lessees may be unable to make their payments to us.

A substantial portion of our current leases require that payments be made in U.S. dollars. If the currency that our lessees typically use in operating their businesses devalues against the U.S. dollar, those lessees could encounter difficulties in making payments in U.S. dollars. Furthermore, many foreign countries have currency and exchange laws regulating international payments that may impede or prevent payments from being paid to us in U.S. dollars. Future leases may provide for payments to be made in euros or other foreign currencies. Any change in the currency exchange rate that reduces the amount of U.S. dollars obtained by us upon conversion of future lease payments denominated in euros or other foreign currencies, may, if not appropriately hedged by us, have a material adverse effect on us and

increase the volatility of our earnings. If payments on our leases are made in foreign currency, our risks and hedging costs will increase.

We operate globally and are affected by our customers’ local and regional economic and other risks.

We believe that our customers’ growth and financial condition are driven by economic growth in their service areas. The largest portion of our lease revenues come from Europe. European airline operations are among the most heavily regulated in the world. At the same time, low-cost carriers have exerted substantial competitive and financial pressure on major European airlines. Low-cost carriers are having similar effects in North America and elsewhere.

Our operations may also be affected by political or economic instability in the areas where we have customers.

We may not be able to enforce our rights as a creditor if a lessee files for bankruptcy outside of the United States.

When a debtor seeks protection under the United States Bankruptcy Code, creditors are automatically stayed from enforcing their rights. In the case of United States-certificated airlines, Section 1110 of the Bankruptcy Code provides certain relief to lessors of aircraft equipment. Section 1110 has been the subject of significant litigation and we can give no assurance that Section 1110 will protect our investment in aircraft or engines in the event of a lessee’s bankruptcy. In addition, Section 1110 does not apply to lessees located outside of the United States and applicable foreign laws may not provide comparable protection.

Liens on our engines or aircraft could exceed the value of such assets, which could negatively affect our ability to repossess, lease or sell a particular engine or aircraft.

Liens that secure the payment of repairers’ charges or other liens may, depending on the jurisdiction, attach to engines and aircaft. Engines also may be installed on airframes to which liens unrelated to the engines have attached. These liens may secure substantial sums that may, in certain jurisdictions or for limited types of liens, exceed the value of the particular engine or aircraft to which the liens have attached. In some jurisdictions, a lien may give the holder the right to detain or, in limited cases, sell or cause the forfeiture of the engine or aircraft. Such liens may have priority over our interest as well as our creditors’ interest in the engines or aircraft, either because they have such priority under applicable local law or because our creditors’ security interests are not filed in jurisdictions outside the United States. These liens and lien holders could impair our ability to repossess and lease or sell the engines or aircraft. We cannot give assurance that our lessees will comply with their obligations to discharge third-party liens on our assets. If they do not, we may, in the future, find it necessary to pay the claims secured by such liens to repossess such assets.

In certain countries, an engine affixed to an aircraft may become an accession to the aircraft and we may not be able to exercise our ownership rights over the engine.

In some jurisdictions, an engine affixed to an aircraft may become an accession to the aircraft, so that the ownership rights of the owner of the aircraft supersede the ownership rights of the owner of the engine. If an aircraft is security for the owner’s obligations to a third-party, the security interest in the aircraft may supersede our rights as owner of the engine. This legal principle could limit our ability to repossess an engine in the event of a lessee bankruptcy or lease default while the aircraft with the engine installed remains in such a jurisdiction. We may suffer a loss if we are not able to repossess engines leased to lessees in these jurisdictions.

RISKS RELATED TO OUR SMALL SIZE AND CORPORATE STRUCTURE

Intense competition in our industry, particularly with major companies with substantially greater financial, personnel, marketing and other resources, could cause our revenues and business to suffer.

The engine and aircraft leasing industry is highly competitive and global. Our primary competitors include GE Engine Leasing, Shannon Engine Support Ltd., Pratt &Whitney, Rolls-Royce Partners Finance and Engine Lease Finance Corporation.

Our primary competitors generally have significantly greater financial, personnel and other resources, as well as a physical presence in more locations, than we do. In addition, competing engine lessors may have lower costs of capital and may provide financial or technical services or other inducements to customers, including the ability to sell or lease aircraft, offer maintenance and repair services or provide other forms of financing that we do not provide. We cannot give assurance that we will be able to compete effectively or that competitive pressures will not adversely affect us.

There is no organized market for the spare engines or the aircraft we purchase. Typically, we purchase engines and aircraft from commercial aircraft operators, engine manufacturers, MROs and other suppliers. We rely on our representatives, advertisements and reputation to generate opportunities to purchase and sell engines and aircraft. The market for purchasing engine and aircraft portfolios is highly competitive, generally involving an auction bidding process. We can give no assurance that engines and aircraft will continue to be available to us on acceptable terms and in the types and quantities we seek consistent with the diversification requirements of our debt facilities and our portfolio diversification goals.

Substantially all of our assets are pledged to our creditors.

Substantially all of our assets are pledged to secure our obligations to creditors. Our revolving credit banks have a lien on all of our assets, including our equity in WEST II. Due to WEST II’s bankruptcy remote structure, that equity is subject to the prior payments of WEST II’s debt and other obligations. Therefore, our rights and the rights of our creditors to participate in any distribution of the assets of WEST II upon its liquidation, reorganization, dissolution or winding up will be subject to the prior claims of WEST II’s creditors. Similarly, the rights of our shareholders are subject to satisfaction of the claims of our lenders and other creditors.

We may be unable to manage the expansion of our operations.

We can give no assurance that we will be able to manage effectively the current and potential expansion of our operations, or that if we are successful expanding our operations that our systems, procedures or controls will be adequate to support our operations, in which event our business, financial condition, results and cash flows could be adversely affected.

Any acquisition or expansion involves various risks, which may include some or all of the following:

Any of the above factors could have a material adverse effect on us.

Compliance with the regulatory requirements imposed on us as a public company results in significant costs that may have an adverse effect on our results.

As a public company, we are subject to various regulatory requirements including, but not limited to, compliance with the Sarbanes-Oxley Act of 2002 and the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. Compliance with these regulations results in significant additional costs to us both directly, through increased audit and consulting fees, and indirectly, through the time required by our limited resources to address such regulations. We have complied with Section 404a of the Sarbanes-Oxley Act as of December 31, 2007, completing our annual assessment of internal controls over financial reporting. We have complied with Section 404b of the Sarbanes-Oxley Act as of December 31, 2009, and our independent registered public accounting firm audits our internal controls over financial reporting. Such compliance requires us to incur additional costs on audit and consulting fees and requires additional management time that may adversely affect our results of operations and cash flows.

We are effectively controlled by one principal stockholder, who has the power to contest the outcome of most matters submitted to the stockholders for approval and to affect our stock prices adversely if he were to sell substantial amounts of his common stock.

As of December 31, 2016, our principal stockholder, Chairman of the Board of Directors and Chief Executive Officer, Mr. Charles F. Willis, IV, beneficially owned or had the ability to direct the voting of 2,744,219 shares of our common stock, representing approximately 43% of the outstanding shares of our common stock. As a result, Mr. Willis effectively controls us and has the power to contest the outcome of substantially all matters submitted to our stockholders for approval, including the election of our board of directors. In addition, future sales by Mr. Willis of substantial amounts of our common stock, or the potential for such sales, could adversely affect the prevailing market price of our common stock.

Our business might suffer if we were to lose the services of certain key employees.

Our business operations depend upon our key employees, including our executive officers. Loss of any of these employees, particularly our Chief Executive Officer, could have a material adverse effect on our business as our key employees have knowledge of our industry and customers and would be difficult to replace.

We are the servicer and administrative agent for the WEST II facility and our cash flows would be materially and adversely affected if we were removed from these positions.

We are the servicer and administrative agent with respect to engines in the WEST II facility. We receive monthly fees of 11.5% as servicer and 2.0% as administrative agent of the aggregate net rents actually received by WEST II on its engines. We may be removed as servicer and administrative agent by the affirmative vote of a requisite number of holders of the WEST II facility notes upon the occurrence of certain specified events, including the following events, subject to WEST II following certain specified procedures and providing us certain cure rights as set forth in the servicing agreement:

As of December 31, 2016, we were in compliance with the financial covenants set forth above. There can be no assurance that we will be in compliance with these covenants in the future or will not otherwise be terminated as service or administrative agent for the WEST II facility. If we are removed, our expenses would increase since our consolidated subsidiary, WEST II, would have to hire an outside provider to replace the servicer and administrative agent functions, and we would be materially and adversely affected. Consequently, our business, financial condition, results of operations and cash flows would be adversely affected.

Provisions in Delaware law and our charter and bylaws might prevent or delay a change of control.

Certain provisions of law, our amended certificate of incorporation, bylaws and amended rights agreement could make the following more difficult: (1) an acquisition of us by means of a tender offer, a proxy contest or otherwise, and (2) the removal of incumbent officers and directors.

Our board of directors has authorized the issuance of shares of Series I Junior Participating Preferred Stock pursuant to our amended rights agreement, by and between us and American Stock Transfer and Trust Company, as rights agent. The rights agreement could make it more difficult to proceed with and tend to discourage a merger, tender offer or proxy contest. Our amended certificate of incorporation also provides that stockholder action can be taken only at an annual or special meeting of stockholders and may not be taken by written consent and, in certain circumstances relating to acquisitions or other changes in control, requires an 80% supermajority vote of all outstanding shares of our common stock. Our bylaws also limit the ability of stockholders to raise matters at a meeting of stockholders without giving advance notice.

ITEM 2.PROPERTIES

Our principal offices are located in Novato, California under a lease that covers 20,534 square feet of office space.   We sub-lease 7,124 square feet of office and warehouse space for our operations in San Diego, California. We lease 30,000 square feet of office and warehouse space in Boynton Beach, Florida.  We lease 30,000 square feet of office and warehouse space in Bridgend, Wales, UK. We also lease facilities for sales and operations in London, UK; Shanghai, China; Singapore; Blagnac, France; and Dublin, Ireland.

ITEM 3.LEGAL PROCEEDINGS

None.

ITEM 4.SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

No matters were submitted to a vote of stockholders during the fourth quarter of the fiscal year 2016.

PART II

ITEM 5.MARKET FOR THE REGISTRANT’S COMMON EQUITY AND RELATED SHAREHOLDER MATTERS

The following information relates to our Common Stock, which is listed on the NASDAQ National Market under the symbol WLFC. As of March 2, 2017 there were approximately 3,004 shareholders of our Common Stock.

The high and low closing sales price of the Common Stock for each quarter of 2016 and 2015, as reported by NASDAQ, are set forth below:

During the years ended December 31, 2016 and 2015, we did not pay cash dividends to our common shareholders. We have not made any dividend payments to our common shareholders since our inception as all available cash has been utilized for the business. We have no intention of paying dividends on our common stock in the foreseeable future. In addition, certain of our debt facilities contain negative covenants which prohibit us from paying any dividends or making distributions of any kind with respect to our common stock.

The following table outlines our Equity Compensation Plan Information.

The 2007 Stock Incentive Plan was approved by shareholders. The 2007 Stock Incentive Plan authorized 2,000,000 shares of common stock. On May 28, 2015, the Company’s shareholders authorized an increase in the number of shares of Common Stock available for grant by 800,000 shares bringing the total to 2,800,000 shares authorized.  2,400,357 shares of restricted stock were granted under the 2007 Stock Incentive Plan by December 31, 2016. Of this amount, 155,745 shares of restricted stock were cancelled and returned to the pool of shares which could be granted under the 2007 Stock Incentive Plan resulting in a net number of 555,388 shares which were available as of December 31, 2016 for future issuance under the 2007 Stock Incentive Plan.

On September 27, 2012, the Company announced that its Board of Directors has authorized a plan to repurchase up to $100.0 million of its common stock over the next 5 years.  The Board of Directors reaffirmed the repurchase plan on April 21, 2015.  The repurchased shares are to be subsequently retired. During 2016, the Company repurchased 1,212,230 shares totaling $29.0 million under our authorized plan. As of December 31, 2016, the total number of common shares outstanding was approximately 6.4 million.

Common stock repurchases, under our authorized plan, in the quarter ended December 31, 2016 were as follows:

ITEM 6.SELECTED FINANCIAL DATA

The following table summarizes our selected consolidated financial data and operating information. The selected consolidated financial and operating data should be read in conjunction with the Consolidated Financial Statements and notes thereto and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included elsewhere in this Form 10-K.

ITEM 7.MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

OVERVIEW

Forward-Looking Statements. This Annual Report on Form 10-K includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact, including statements regarding prospects or future results of operations or financial position, made in this Annual Report on Form 10-K are forward-looking. We use words such as anticipates, believes, expects, future, intends, and

similar expressions to identify forward-looking statements. Forward-looking statements reflect management’s current expectations and are inherently uncertain. Actual results could differ materially for a variety of reasons, including, among others: the effects on the airline industry and the global economy of events such as terrorist activity, changes in oil prices and other disruptions to the world markets; trends in the airline industry, including growth rates of markets and other economic factors; risks associated with owning and leasing jet engines and aircraft; our ability to successfully negotiate equipment purchases, sales and leases, to collect outstanding amounts due and to control costs and expenses; changes in interest rates and availability of capital, our ability to continue to meet the changing customer demands; regulatory changes affecting airline operations, aircraft maintenance, accounting standards and taxes; and the market value of engines and other assets in our portfolio. These risks and uncertainties, as well as other risks and uncertainties that could cause our actual results to differ significantly from management’s expectations, are described in greater detail in Item 1A of Part I, “Risk Factors,” which, along with the previous discussion, describes some, but not all, of the factors that could cause actual results to differ significantly from management’s expectations.

Explanatory Note:  Certain 2015 and 2014 amounts include adjustments to prior periods see "Note 1. Summary of Significant Accounting Policies (c) Correction of Immaterial Errors -  Consolidated Financial Statements" for further disclosure.

General. Our core business is acquiring and leasing commercial aircraft engines and related aircraft equipment pursuant to operating leases, and the selective sale of such engines, all of which we sometimes refer to as “equipment.” As of December 31, 2015, all of our leases were operating leases. As of December 31, 2016, we had 80 lessees in 43 countries. Our portfolio is continually changing due to acquisitions and sales. As of December 31, 2016, our lease portfolio consisted of 208 engines and related equipment, 11 aircraft and 5 spare engine parts packages with an aggregate net book value of $1,136.6 million. As of December 31, 2016, we also managed 542engines and related equipment on behalf of other parties. 

In 2016, we purchased, through our wholly owned subsidiary Willis Asset Management Limited (“Willis Asset Management”), the business and assets of Total Engine Support Limited (“TES”).  TES has been the engine management and consulting business of the TES Aviation Group.

In 2013, we launched Willis Aeronautical Services, Inc. (“Willis Aero”), a wholly-owned subsidiary, whose primary focus is the sale of aircraft engine parts and materials through the acquisition or consignment of aircraft and engines from third parties. 

On June 3, 2014 we entered into an agreement with China Aviation Supplies Import & Export Corporation (“CASC”) to participate in a joint venture named CASC Willis Engine Lease Company Limited (“CASC Willis”), a new joint venture based in Shanghai, China. Each partner holds a fifty percent interest in the joint venture.    In October 2014, we made a $15.0 million initial capital contribution, representing our fifty percent, up-front funding contribution to the new joint venture. The company acquires and leases jet engines to Chinese airlines and concentrates on meeting the fast growing demand for leased commercial aircraft engines and aviation assets in the People’s Republic of China. CASC Willis owned a lease portfolio of 3 engines with a net book value of $49.1 million as of December 31, 2016. Our investment in the joint venture is $12.9 million as of December 31, 2016. During 2016, CASC was reorganized, with portions of its partnership interest in CASC Willis being transferred to three Chinese airlines and another government-owned entity.  The 2016 CASC reorganization resulted in no voting structure change to the joint venture.

On May 25, 2011, we entered into an agreement with Mitsui & Co., Ltd. to participate in a joint venture formed as a Dublin-based Irish limited company — Willis Mitsui & Company Engine Support Limited (“WMES”) for the purpose of acquiring and leasing jet engines. Each partner holds a fifty percent interest in the joint venture. WMES owns a lease portfolio of 30 engines with a net book value of $268.0 million at December 31, 2016.

We actively manage our portfolio and structure our leases to maximize the residual values of our leased assets. Our leasing business focuses on popular Stage III commercial jet engines manufactured by CFMI, General Electric,

Pratt & Whitney, Rolls Royce and International Aero Engines. These engines are the most widely used engines in the world, powering Airbus, Boeing, McDonnell Douglas, Bombardier and Embraer aircraft.

CRITICAL ACCOUNTING POLICIES AND ESTIMATES

The preparation of our consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an ongoing basis, we evaluate our estimates, including those related to residual values, estimated asset lives, impairments and bad debts. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

We believe the following critical accounting policies, grouped by our activities, affect our more significant judgments and estimates used in the preparation of our consolidated financial statements:

Leasing Related Activities. Revenue from leasing of aircraft equipment is recognized as operating lease revenue on a straight-line basis over the terms of the applicable lease agreements. Where collection cannot be reasonably assured, for example, upon a lessee bankruptcy, we do not recognize revenue until cash is received. We also estimate and charge to income a provision for bad debts based on our experience in the business and with each specific customer and the level of past due accounts. The financial condition of our customers may deteriorate and result in actual losses exceeding the estimated allowances. In addition, any deterioration in the financial condition of our customers may adversely affect future lease revenues. As of December 31, 2016 all of our engine leases are accounted for as operating leases. Under an operating lease, we retain title to the leased equipment, thereby retaining the potential benefit and assuming the risk of the residual value of the leased equipment. 

We generally depreciate engines on a straight-line basis over 15 years to a 55% residual value. Aircraft are generally depreciated on a straight-line basis over 13-20 years to a 15%-17% residual value. Spare parts packages are generally depreciated on a straight-line basis over 14-15 years to a 25% residual value. Major overhauls paid for by us, which improve functionality or extend the original useful life, are capitalized and depreciated over the shorter of the estimated period to the next overhaul (“deferral method”) or the remaining useful life of the equipment. We do not accrue for planned major maintenance. For equipment which is unlikely to be repaired at the end of its current expected life, and is likely to be disassembled upon lease termination, we depreciate the equipment over its estimated life to a residual value based on an estimate of the wholesale value of the parts after disassembly. As of December 31, 2016, 56 engines and 6 aircraft having a net book value of $126.1 million were depreciated under this policy with estimated useful lives ranging from 1 to 124 months.

Asset Valuation. Long-lived assets and certain identifiable intangibles to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable, and long-lived assets and certain identifiable intangibles to be disposed of are reported at the lower of carrying amount or fair value less cost to sell.

On a quarterly basis, management monitors the lease portfolio for events which may indicate that a particular asset may need to be evaluated for potential impairment. These events may include a decision to part-out or sell an asset, knowledge of specific damage to an asset, or supply/ demand events which may impact the Company’s ability to lease an asset in the future. On an annual basis, even absent any such ‘triggering event’, we evaluate the carrying value of all assets in our lease portfolio to determine if any impairment exists, by performing an undiscounted cash flow test for each asset.

Impairment is identified by comparison of undiscounted forecasted cash flows, including estimated sales proceeds, over the life of the asset with the asset’s book value. If the forecasted undiscounted cash flows are less than the book value, we write the asset down to its fair value. When evaluating for impairment, we group assets at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. In our

portfolio, this is at the individual asset level (e.g., engine or aircraft), as each asset generates its own stream of cash flows, including lease rents, maintenance reserves and repair costs.

We must make assumptions which underlie the most significant and subjective estimates in determining whether any impairment exists.  Those estimates, and the underlying assumptions, are as follows:

If the undiscounted forecasted cash flows and fair value of our long-lived assets decrease in the future we may incur impairment charges.

Management continuously monitors the aviation industry and evaluates any trends, events or uncertainties involving airlines, individual aircraft and engine models, as well as the engine leasing and sale market which would materially affect the methodology or assumptions employed by WLFC. We do not consider there to be any trends, events or uncertainties that currently exist or that are reasonably likely to occur that would materially affect our methodology or assumptions. However, should any arise, we will adjust our methodology and our disclosure accordingly.

Spare parts inventory is stated at lower of cost or net realizable value. An impairment charge for excess or inactive inventory is recorded based upon an analysis that considers current inventory levels, historical usage patterns, future sales expectations and salvage value.

Accounting for Maintenance Expenditures and Maintenance Reserves. Use fees received are recognized in revenue as maintenance reserve revenue if they are not reimbursable to the lessee. Use fees that are reimbursable are recorded as a maintenance reserve liability until they are reimbursed to the lessee or the lease terminates, at which time they are recognized in revenue as maintenance reserve revenue. Our expenditures for maintenance are expensed as incurred. Expenditures that meet the criteria for capitalization are recorded as an addition to equipment recorded on the balance sheet.

Accounting for Maintenance Rights. We identify, measure and account for maintenance right assets and liabilities associated with acquisitions of equipment with in-place leases. A maintenance right asset represents the fair value of the contractual right under a lease to receive equipment in an improved maintenance condition as compared to the maintenance condition on the acquisition date. A maintenance right liability represents the Company's obligation to pay the lessee for the difference between the lease-end contractual maintenance condition of the equipment and the actual maintenance condition of the equipment on the acquisition date.  The equipment condition at the end of the lease term may result in either overhaul work being performed by the lessee to meet the required return condition or a financial settlement.

When a capital event is performed on the equipment by the lessee, which satisfies their maintenance right obligation, the maintenance rights are added to the equipment basis and depreciated to the next capital event.  When equipment is sold before the end of the pre-existing lease, the maintenance rights are applied against any accumulated maintenance reserves, if paid by the lessee, and the remaining balance is applied to the disposition gain or loss.  When a lease terminates, an end of lease true-up is performed and the maintenance right is applied against the accumulated maintenance reserves or, for non-reserve lessees the final settlement payment, and any remaining net maintenance right is recorded in the income statement.

YEAR ENDED DECEMBER 31, 2016 COMPARED TO THE YEAR ENDED DECEMBER 31, 2015

Revenue is summarized as follows:

Lease Rent Revenue. Our lease rent revenue for the year ended December 31, 2016 increased by 11.0% over the comparable period in 2015. This increase primarily reflects a higher average portfolio utilization in the current period, which translated into a higher percentage of lease rent revenue earning assets.  The aggregate net book value of equipment held for lease at December 31, 2016 and 2015, was $1,136.6 million and $1,109.2 million, respectively, an increase of 2.5%. Portfolio utilization is defined as the net book value of on-lease assets as a percentage of the net book value of total lease assets. As of December 31, 2016 and 2015, approximately 93% and 90%, respectively, of equipment by net book value was on-lease. The average utilization for the year ended December 31, 2016 was 90% compared to 87% in the prior year. During the year ended December 31, 2016, 20 engines and 1 aircraft were added to our lease portfolio at a total cost of $153.1 million (including capitalized costs). During the year ended December 31, 2015, 12 engines and 6 aircraft were added to our lease portfolio at a total cost of $172.7 million (including capitalized costs).

Maintenance Reserve Revenue. Our maintenance reserve revenue for the year ended December 31, 2016 increased 6.9% to $57.1 million from $53.4 million for the comparable period in 2015. The increase was due to both higher utilization, driving a $5.7 million increase in short term maintenance revenues partially offset by $2.0 million of lower maintenance reserve revenues related to a lower termination of long term leases in the year ended December 31, 2016 than in the year ago period. 

Spare Parts and Equipment Sales. Spare parts and equipment sales for the year ended December 31, 2016 was $17.8 million compared to $25.6 million in 2015.  Equipment sales of $3.3 million were for the sale of three airframes during the year ended December 31, 2016.  Equipment sales were $10.0 million for the sale of two airframe, one engine and related equipment for the year ended December 31, 2015.   Spare parts sales for the year ended December 31, 2016 were $14.5 million compared to $15.6 million in the comparable period in 2015. 

Gain on Sale of Leased Equipment. During the year ended December 31, 2016, we sold 7 engines and various engine-related equipment from the lease portfolio for a net gain of $3.5 million. During the year ended December 31, 2015, we sold 8 engines and various engine-related equipment from the lease portfolio for a net gain of $8.3 million.

Other Revenue. Our other revenue consists primarily of management fee income, lease administration fees and third party consignment commissions earned by Willis Aero. Other revenue increased $6.3 million from the prior year primarily due to recognizing revenue of $4.0 million of security payments for aircraft upon default of a lessee and $0.6 million foreign subsidy recognized in the period. The foreign subsidy was received from the People’s Republic of China resulting from our China subsidiary operating in the Shanghai free trade zone.

Depreciation and Amortization Expense. Depreciation and amortization expense decreased $3.1 million or 4.5% to $66.3 million for the year ended December 31, 2016, from the comparable period in 2015 primarily due to changes in portfolio mix associated with our ongoing portfolio management efforts.

Cost of Spare Parts and Equipment Sales. Cost of spare parts and equipment sales for the year ended December 31, 2016 was $13.3 million a decrease of 25.5% from the comparable period in 2015.  Cost of equipment sales was $2.4 million and $5.7 million in the year ended December 31, 2016 and 2015, respectively. Cost of spare parts sales for the

year ended December 31, 2016 were $10.7 million compared to $12.1 million in the comparable period in 2015.  Gross margin on spare parts sales for 2016 was 24.6% compared to 22.4% for 2015 primarily due to a change in the mix of parts sold in 2016. 

Write-down of Equipment. Write-down of equipment to their estimated fair values totaled $9.5 million for the year ended December 31, 2016, an increase of $0.3 million from the $9.2 million recorded in the comparable period in 2015. A writedown of $5.5 million was recorded due to the adjustment of the carrying value for six impaired engines and one impaired aircraft within the portfolio to reflect estimated market value.   A further write-down of equipment totaling $2.0 million was recorded in the year ended December 31, 2016 due to a management decision to consign one engine for part-out and sale, in which the asset’s net book value exceeded the estimated proceeds.  An additional writedown of $2.0 million was recorded in year ended December 31, 2016 to adjust the carrying value of engine parts held on consignment for which market conditions for the sale of parts has changed.

A write-down of equipment totaling $9.2 million was recorded in the year ended December 31, 2015. This amount includes a write-down of equipment totaling $5.5 million due to a management decision to consign four engines for part-out and sale, in which the assets’ net book value exceeded the estimated proceeds from part-out. Write-downs on held for use equipment to their estimated fair values totaled $0.6 million for the year ended December 31, 2015 due to an adjustment of carrying values for certain impaired parts packages within the portfolio to reflect estimated market values. A further write-down of $2.8 million was recorded in the year ended December 31, 2015 to adjust the carrying value of engine parts for which market conditions for the sale of parts has changed.  An additional write-down of $0.3 million was recorded in the year ended December 31, 2015 based on a comparison of the inventory values with the revised net proceeds expected from part sales.

General and Administrative Expenses. General and administrative expenses increased 11.8% to $47.8 million for the year ended December 31, 2016, from the comparable period in 2015 due primarily to increases in contingency bonus ($3.1 million) resulting from improved operating results (pre-tax earnings and utilization) as well as increases in salary expense ($1.4 million) from increased headcount, and higher legal expenses ($1.0 million).

Technical Expense. Technical expenses consist of the cost of engine repairs, engine thrust rental fees, outsourced technical support services, sublease engine rental expense, engine storage and freight costs. These expenses decreased 25.6% to $7.0 million for the year ended December 31, 2016, from the comparable period in 2015 due primarily to a decrease in engine maintenance costs due to reduced engine shop visits ($1.4 million) lower engine thrust rental fees ($0.7 million), and lower engine technical services expense ($0.3 million) due to decreased engine returns.

Net Finance Costs. Net finance costs include interest expense and gain on debt extinguishment. Net finance costs increased 9.0% to $41.3 million for 2016, from the comparable period in 2015, due primarily to higher average debt balances in the current period compared to the year ago period and the recording of a gain on debt extinguishment of $1.2 million in the prior year period. The average notes payable balances for the years ended December 31, 2016 and 2015 were $892.4 million and $858.2 million, respectively, an increase of 4.0%.  As of December 31, 2016, $619.7 million of our debt is tied to one-month U.S. dollar LIBOR which increased from an average of 0.21% for 2015 to an average of 0.45% for 2016 (average of month-end rates). At December 31, 2016 and 2015, one-month LIBOR was 0.77% and 0.43%, respectively.

To mitigate exposure to interest rate changes, we periodically enter into interest rate swap agreements. As of December 31, 2016, such swap agreement had a notional outstanding amount of $100.0 million, with a remaining term of 52 months. No interest rate swap agreements existed during the year ended December 31, 2015.

Income Taxes. Income tax expense for the year ended December 31, 2016, increased to $9.9 million from $6.3 million for the comparable period in 2015. The effective tax rate for the years ended December 31, 2016 and December 31, 2015 were 41.2% and 49.4%, respectively.  This decrease was due to lower forecasted permanent non-deductible expenses for executive compensation (IRS code 162(m) calculation) and changes in the proportions of revenue generated within and outside of California during the year ended December 31, 2016.

 Our tax rate is subject to change based on changes in the mix of assets leased to domestic and foreign lessees, the proportions of revenue generated within and outside of California, the amount of executive compensation exceeding $1.0 million as defined in IRS code 162(m) and numerous other factors, including changes in tax law.

YEAR ENDED DECEMBER 31, 2015 COMPARED TO THE YEAR ENDED DECEMBER 31, 2014

Revenue is summarized as follows:

Lease Rent Revenue. Our lease rent revenue for the year ended December 31, 2015 increased by 6.5% over the comparable period in 2014. This increase primarily reflects an increase in the average size of the lease portfolio and higher average portfolio utilization in the current period, which translated into a higher amount of equipment on lease.  The aggregate of net book value of equipment held for lease at December 31, 2015 and 2014, was $1,109.2 million and $1,066.4 million, respectively, an increase of 4.0%. Portfolio utilization is defined as the net book value of on-lease assets as a percentage of the net book value of total lease assets. As of December 31, 2015 and 2014, approximately 90% and 79%, respectively, of equipment by net book value was on-lease. The average utilization for the year ended December 31, 2014 was 87% compared to 83% in the prior year. During the year ended December 31, 2015, 12 engines and 6 aircraft were added to our lease portfolio at a total cost of $172.7 million (including capitalized costs). During the year ended December 31, 2014, 21 engines and one aircraft were added to our lease portfolio at a total cost of $137.4 million (including capitalized costs).

Maintenance Reserve Revenue. Our maintenance reserve revenue for the year ended December 31, 2015 increased 0.1% to $53.4 million from $53.3 million for the comparable period in 2014. The increase was due to higher maintenance reserves billed reflecting increased usage of engines under lease resulting from higher portfolio utilization in 2015 compared to 2014.

Spare Parts and Equipment Sales. Spare parts and equipment sales for the year ended December 31, 2015 was $25.6 million compared to $8.9 million in 2014.  The increase was due to the sale of two airframes and other related equipment in the current period related to  recent aircraft purchases as well as growth in spare parts sales due to an increase in inventory acquisitions in late 2014 at Willis Aero.

Gain on Sale of Leased Equipment. During the year ended December 31, 2015, we sold 8 engines and sold various engine-related equipment from the lease portfolio for a net gain of $8.3 million. During the year ended December 31, 2014, we sold 7 engines, exchanged 2 engines and sold various engine-related equipment from the lease portfolio for a net gain of $5.9 million.

Other Revenue. Our other revenue consists primarily of management fee income, lease administration fees and third party consignment commissions earned by Willis Aero. Other revenue decreased $1.8 million from the prior year primarily due to a decrease in fees earned related to engines managed on behalf of third parties and lower commissions on third party spare parts sales.

Depreciation and Amortization Expense. Depreciation and amortization expense increased $4.1 million or 6.3% to $69.4 million for the year ended December 31, 2015, from the comparable period in 2014 due to growth in the lease portfolio and changes in estimates of useful lives and residual values on certain older engine types.

Cost of Spare Parts and Equipment Sales. Cost of spare parts and equipment sales for the year ended December 31, 2015 was $17.8 million an increase of 138.8% from the comparable period in 2014.  Gross margin on spare parts sales for 2015 was 22.4% compared to 16.2% for 2014 primarily due to a change in the mix of parts sold in 2015.  Cost of equipment sales increased to $5.7 million in 2015 from Nil in 2014 due to the sale two airframes and other related equipment in 2015 related to recent aircraft purchases.

Write-down of Equipment. Write-down of equipment to their estimated fair values totaled $9.2 million for the year ended December 31, 2015, an increase of $3.6 million from the $5.6 million recorded in the comparable period in 2014. A write-down of equipment totaling $5.5 million was recorded in the year ended December 31, 2015 due to a management decision to consign four engines for part-out and sale, in which the assets’ net book value exceeded the estimated proceeds from part-out. Write-downs on held for use equipment to their estimated fair values totaled $0.6 million for the year ended December 31, 2015 due to an adjustment of carrying values for certain impaired parts packages within the portfolio to reflect estimated market values. A further write-down of $2.8 million was recorded in the year ended December 31, 2015 to adjust the carrying value of engine parts for which market conditions for the sale of parts has changed.  An additional write-down of $0.3 million was recorded in the year ended December 31, 2015 based on a comparison of the inventory values with the revised net proceeds expected from part sales.

A write-down of equipment totaling $5.6 million was recorded in the year ended December 31, 2014. This amount includes a write-down of equipment totaling $2.6 million due to a management decision to consign six engines for part-out and sale, in which the assets’ net book value exceeded the estimated proceeds from part-out. Write-downs on held for use equipment to their estimated fair values totaled $2.4 million for the year ended December 31, 2014, due to the adjustment of carrying values for certain impaired engines within the portfolio to reflect estimated market values. A further write-down of $0.6 million was recorded in the year ended December 31, 2014 to adjust the carrying value of engine parts for which market conditions for the sale of parts has changed.

General and Administrative Expenses. General and administrative expenses increased 19.2% to $42.7 million for the year ended December 31, 2015, from the comparable period in 2014 due primarily to increases in contingency bonus ($2.5 million) resulting from improved operating results (pre-tax earnings and utilization) as well as increases in salary expense ($1.6 million), corporate aircraft expense ($1.4 million), bad debt expense ($0.7 million), stock based compensation ($0.6 million) and other selling expenses ($0.5 million), which was partially offset by lower legal expenses ($0.7 million).

Technical Expense. Technical expenses consist of the cost of engine repairs, engine thrust rental fees, outsourced technical support services, sublease engine rental expense, engine storage and freight costs. These expenses decreased 23.8% to $9.4 million for the year ended December 31, 2015, from the comparable period in 2014 due primarily to a decrease in engine maintenance costs due to lower engine repair activity ($3.6 million) and decreased engine storage fees ($0.2 million), which was partially offset by higher thrust rental fees due to an increase in the number of engines operated at higher thrust levels under the CFM thrust rental program ($0.5 million) and increased third party technical service fees ($0.3 million).

Net Finance Costs. Net finance costs include interest expense and gain on debt extinguishment. Net finance costs increased 2.2% to $37.9 million for 2015, from the comparable period in 2014, due primarily to higher average debt balances in the current period compared to the year ago period partially offset by the recording of a gain on debt extinguishment of $1.2 million in the current period. The average notes payable balances for the years ended December 31, 2015 and 2014 were $878.7 million and $769.2 million, respectively, an increase of 14.2%.  As of December 31, 2015, $562.1 million of our debt is tied to one-month U.S. dollar LIBOR which increased from an average of 0.16% for 2014 to an average of 0.21% for 2015 (average of month-end rates). At December 31, 2015 and 2014, one-month LIBOR was 0.43% and 0.17%, respectively. To mitigate exposure to interest rate changes, we periodically enter into interest rate swap agreements. Our previous interest rate swap agreements matured in November 2013.  For 2014, interest expense was reduced by $0.5 million resulting from interest rate swaps.

Income Taxes. Income tax expense for the year ended December 31, 2015, increased to $6.3 million from $4.6 million for the comparable period in 2014. The effective tax rate for the years ended December 31, 2015 and December

31, 2014 were 49.4% and 38.8%, respectively.  This increase was primarily due to the impact of state and foreign taxes and the IRS code 162(m) calculation for executive compensation during the year ended December 31, 2015.   Our tax rate is subject to change based on changes in the mix of assets leased to domestic and foreign lessees, the proportions of revenue generated within and outside of California, the amount of executive compensation exceeding $1.0 million as defined in IRS code 162(m) and numerous other factors, including changes in tax law.

RECENT ACCOUNTING PRONOUNCEMENTS

In January 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which eliminates the requirement to determine the fair value of individual assets and liabilities of a reporting unit to measure goodwill impairment. Under the amendments in the new ASU, goodwill impairment testing will be performed by comparing the fair value of the reporting unit with its carrying amount and recognizing an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. The new standard is effective for annual and interim goodwill impairment tests in fiscal years beginning after December 15, 2019, and should be applied on a prospective basis. Early adoption is permitted for annual or interim goodwill impairment testing performed after January 1, 2017. The Company is currently evaluating the impact of adopting this guidance.

In November 2016, the FASB issued ASU 2016-18, Restricted Cash, which requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. ASU 2016-08 is effective for fiscal years beginning after December 15, 2018 (including interim periods within those periods) using a retrospective transition method to each period presented. The Company is currently evaluating the impact of adopting this guidance.

In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The standard is intended to simplify several areas of accounting for share-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. Althrough early adoption is permitted, we will adopt these provisions prospectively in the first quarter of fiscal 2017.  These changes will impact our tax provision, cash flows from operating activities and cash flows from financing activities.  We will continue to estimate forfeitures each period, so there will be no change associated with forfeitures.  Excess tax benefits and deficiencies are heavily impacted by factors outside of our control such as the number of stock options exercised and the market price of our stock.

In February 2016, the FASB issued ASU 2016-02, Leases (topic 842).  The FASB issued this update to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The updated guidance is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of the update is permitted. The Company is evaluating the impact of the adoption of this update on our consolidated financial statements and related disclosures.

In July 2015, the FASB issued ASU 2015-11 ,Simplifying the Measurement of Inventory, which simplifies the measurement of inventory by requiring certain inventory to be measured at the lower of cost or net realizable value. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017 and for interim periods therein. We are evaluating the impact that this new guidance will have on our consolidated financial position.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which supersedes previous revenue recognition guidance. The new standard requires that a company recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the company expects to receive in exchange for those goods or services. Companies will need to use more judgment and estimates than under the guidance currently in effect, including estimating the amount of variable revenue to recognize over each identified performance obligation. Additional disclosures will be required to help users of financial statements understand the nature, amount and timing of revenue and cash flows arising from contracts. In July 2016, the FASB deferred the effective date for annual reporting periods beginning after December 15, 2017 (including interim reporting periods within those periods).

Early adoption is permitted to the original effective date of periods beginning after December 15, 2017 (including interim reporting periods within those periods). The amendments may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of initial application. While we have not completed our assessment of the new revenue recognition standard, we currently expect that this new standard will not have a material impact on our consolidated financial statements.

LIQUIDITY AND CAPITAL RESOURCES

We finance our growth through borrowings secured by our equipment lease portfolio. Cash of approximately $149.0 million, $192.7 million and $154.4 million, in the years ended December 31, 2016, 2015, and 2014, respectively, was derived from this borrowing activity.  Also in 2016 we generated $19.8 million of cash from the sale of preferred stock.  In these same time periods $114.0 million, $153.8 million and $101.1 million, respectively, was used to pay down related debt. Cash flow from operating activities generated $100.9 million, $107.4 million and $62.8 million in the years ended December 31, 2016, 2015, and 2014, respectively.

At December 31, 2016, $4.6 million in cash and cash equivalents and restricted cash were held in foreign subsidiaries. We do not intend to repatriate the funds held in foreign subsidiaries to the United States. In the event that we decide to repatriate these funds to the United States, we would be required to accrue and pay taxes upon the repatriation.

Our primary use of funds is for the purchase of equipment for lease. Purchases of equipment (including capitalized costs) totaled $173.7 million, $174.8 million and $119.0 million for the years ended December 31, 2016, 2015, and 2014, respectively.

During 2016, we made $0.6 million of capital contributions to our investment in WMES and received $1.3 million in distributions.  During 2015, we made additional capital contributions of $2.6 million to our investment in WMES. 

On June 3, 2014 we entered into an agreement with China Aviation Supplies Import & Export Corporation (“CASC”) to participate in a joint venture named CASC Willis Engine Lease Company Limited (“CASC Willis”), a new joint venture based in Shanghai, China. Each partner holds a fifty percent interest in the joint venture.    In October 2014, we made a $15.0 million initial capital contribution, representing our fifty percent, up-front funding contribution to the new joint venture. The company acquires and leases jet engines to Chinese airlines and concentrates on meeting the fast growing demand for leased commercial aircraft engines and aviation assets in the People’s Republic of China. CASC Willis owned a lease portfolio of 3 engines with a net book value of $49.1 million as of December 31, 2016. Our investment in the joint venture is $12.9 million as of December 31, 2016. During 2016, CASC was reorganized, with portions of its partnership interest in CASC Willis being transferred to three Chinese airlines and another government-owned entity.  The 2016 CASC reorganization resulted in no voting structure change to the joint venture.

Cash flows from operations are driven significantly by payments made under our lease agreements, which comprise lease revenue, security deposits and maintenance reserves, and are offset by interest expense and general and administrative costs. Cash received as maintenance reserve payments for some of our engines on lease are partially restricted by our debt arrangements. The lease revenue stream, in the short-term, is at fixed rates while a portion of our debt is at variable rates. If interest rates increase, it is unlikely we could increase lease rates in the short term and this would cause a reduction in our earnings and operating cash flows. Revenue and maintenance reserves are also affected by the amount of equipment off lease. Approximately 93% and 90%, by book value, of our assets were on-lease as of December 31, 2016 and December 31, 2015, respectively. The average utilization rate for the year ended December 31, 2016 was 90% compared to 87% a year ago. If there is an increase in off-lease rates or deterioration in lease rates that are not offset by reductions in interest rates, there will be a negative impact on earnings and cash flows from operations.

At December 31, 2016, notes payable consists of loans totaling $900.3 million payable over periods of approximately 1.0 years to 7.5 years with interest rates varying between approximately 2.6% and 5.5%. Substantially all of our assets are pledged to secure our obligations to creditors. For further information on our debt instruments, see the "Notes Payable" Note 4 in Part II, Item 8 of  this Form 10-K.

Virtually all of the above debt requires our ongoing compliance with the covenants of each financing, including debt/equity ratios, minimum tangible net worth and minimum interest coverage ratios, and other eligibility criteria including customer and geographic concentration restrictions. In addition, under these facilities, we can typically borrow up to 85% of an engine’s net book value and 65% of spare part’s net book value. Therefore we must have other available funds for the balance of the purchase price of any new equipment to be purchased or we will not be permitted to draw on these facilities. The facilities are also cross-defaulted against other facilities. If we do not comply with the covenants or eligibility requirements, we may not be permitted to borrow additional funds and accelerated payments may become necessary. Additionally, much of the above debt is secured by engines to the extent that engines are sold, repayment of that portion of the debt could be required.

At December 31, 2016, we are in compliance with the covenants specified in the revolving credit facility, including the Interest Coverage Ratio requirement of at least 2.25 to 1.00, and the Total Leverage Ratio requirement to remain below 4.25 to 1.00. As defined in the revolving credit facility Credit Agreement, the Interest Coverage Ratio is the ratio of Earnings before Interest, Taxes, Depreciation and Amortization and other one-time charges (EBITDA) to Consolidated Interest Expense and the Total Leverage Ratio is the ratio of Total Indebtedness to Tangible Net Worth. At December 31, 2016, we are in compliance with the covenants specified in the WEST II indenture and servicing agreement.

Approximately $23.6 million of our debt is repayable during 2017.  Such repayments primarily consist of scheduled installments due under term loans. Repayments are funded by the use of unrestricted cash reserves and from cash flows from ongoing operations. The table below summarizes our contractual commitments at December 31, 2016:

We have estimated the interest payments due under long-term debt by applying the interest rates applicable at December 31, 2016 to the remaining debt, adjusted for the estimated debt repayments identified in the table above. Actual interest payments made will vary due to changes in the rates for one-month LIBOR.

The following table lists our properties and their remaining lease commitments: