SUMMARY OF FINANCIAL STATEMENT PREPARATION AND SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

Air Transport Services Group, Inc. is a holding company whose subsidiaries primarily operate within the airfreight and logistics industry. The Company leases aircraft and provides airline operations, ground services, aircraft modification and maintenance services and other support services mainly to the cargo transportation and package delivery industries. The Company's subsidiaries offer a range of complementary services to delivery companies, freight forwarders, airlines and government customers.

The Company's leasing subsidiary, Cargo Aircraft Management, Inc. (“CAM”), leases aircraft to each of the Company's airlines as well as to non-affiliated airlines and other lessees. The airlines, ABX Air, Inc. (“ABX”) and Air Transport International, Inc. (“ATI”), each have the authority, through their separate U.S. Department of Transportation ("DOT") and Federal Aviation Administration ("FAA") certificates, to transport cargo worldwide. The Company provides air transportation services to a concentrated base of customers. The Company provides a combination of aircraft, crews, maintenance and insurance services for a customer's transportation network through customer "CMI" and "ACMI" agreements and through charter contracts in which aircraft fuel is also included. ATI provides passenger transportation to the U.S. Military using "combi" aircraft, which are certified to carry passengers as well as cargo on the main deck. In addition to its aircraft leasing and flight services the Company sells aircraft parts, provides aircraft maintenance and modification services, equipment maintenance services and manages mail and package sorting services for customers.

Basis of Presentation

The accompanying consolidated financial statements include the accounts of Air Transport Services Group, Inc. and its wholly-owned subsidiaries. Investments in an affiliate in which the Company has significant influence but does not exercise control are accounted for using the equity method of accounting. Using the equity method, the Company’s share of a nonconsolidated affiliate's income or loss is recognized in the consolidated statement of earnings and cumulative post-acquisition changes in the investment are adjusted against the carrying amount of the investment. Inter-company balances and transactions are eliminated. The financial statements of the Company are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP").

Revenues and operating expenses include the activities of PEMCO World Air Services, Inc., ("Pemco") a wholly owned subsidiary, for periods since its acquisition by the Company on December 30, 2016. Pemco offers aircraft maintenance and modification services. Certain historical expenses related to the Company's other aircraft maintenance and modification businesses have been reclassified from Other operating expenses to Maintenance, materials and repairs to conform with the current year presentation of the consolidated statements of operations.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the consolidated financial statements. Estimates and assumptions are used to record allowances for uncollectible amounts, self-insurance reserves, spare parts inventory, depreciation and impairments of property, equipment, goodwill and intangibles, stock warrants and other financial instruments, post-retirement obligations, income taxes, contingencies and litigation. Changes in estimates and assumptions may have a material impact on the consolidated financial statements.

Cash and Cash Equivalents

The Company classifies short-term, highly liquid investments with maturities of three months or less at the time of purchase as cash and cash equivalents. These investments, consisting of money market funds, are recorded at cost, which approximates fair value. Substantially all deposits of the Company’s cash are held in accounts that exceed federally insured limits. The Company deposits cash in common financial institutions which management believes are financially sound.

Accounts Receivable and Allowance for Uncollectible Accounts

The Company's accounts receivable is primarily due from its significant customers (see Note B), other airlines, the U.S. Postal Services ("USPS"), delivery companies and freight forwarders. The Company performs a quarterly evaluation of the accounts receivable and the allowance for uncollectible accounts by reviewing specific customers' recent payment history, growth prospects, financial condition and other factors that may impact a customer's ability to pay. The Company establishes an allowance for uncollectible accounts for probable losses due to a customer's potential inability or unwillingness to make contractual payments. Account balances are written off against the allowance when the Company ceases collection efforts.

Inventory

The Company’s inventory is comprised primarily of expendable aircraft parts and supplies used for aircraft maintenance. Inventory is generally charged to expense when issued for use on a Company aircraft. The Company values its inventory of aircraft parts and supplies at weighted-average cost and maintains a related obsolescence reserve. The Company records an obsolescence reserve on a base stock of inventory for each fleet type. The amortization of base stock for the obsolescence reserve corresponds to the expected life of each fleet type. Additionally, the Company monitors the usage rates of inventory parts and segregates parts that are technologically outdated or no longer used in its fleet types. Slow moving and segregated items are actively marketed and written down to their estimated net realizable values based on market conditions.

Management analyzes the inventory reserve for reasonableness at the end of each quarter. That analysis includes consideration of the expected fleet life, amounts expected to be on hand at the end of a fleet life, and recent events and conditions that may impact the usability or value of inventory. Events or conditions that may impact the expected life, usability or net realizable value of inventory include additional aircraft maintenance directives from the FAA, changes in DOT regulations, new environmental laws and technological advances.

Goodwill and Intangible Assets

The Company assesses, during the fourth quarter of each year, the carrying value of goodwill. The first step of the assessment is the estimation of fair value of each reporting unit, which is compared to the carrying value. If step one indicates that impairment potentially exists, a second step is performed to measure the amount of impairment, if any. Goodwill impairment exists when the implied fair value of goodwill is less than its carrying value. The Company also conducts impairment assessments of goodwill, indefinite-lived intangible assets and finite-lived intangible assets whenever events or changes in circumstance indicate an impairment may have occurred. Finite-lived intangible assets are amortized over their estimated useful economic lives.

Property and Equipment

Property and equipment held for use is stated at cost, net of any impairment recorded. The cost and accumulated depreciation of disposed property and equipment are removed from the accounts with any related gain or loss reflected in earnings from operations.

Depreciation of property and equipment is provided on a straight-line basis over the lesser of the asset’s useful life or lease term. Depreciable lives are summarized as follows:



Boeing 767, 757 and 737 aircraft and flight equipment	10 to 18 years
Ground equipment	3 to 10 years
Leasehold improvements, facilities and office equipment	3 to 25 years

The Company periodically evaluates the useful lives, salvage values and fair values of property and equipment. Acceleration of depreciation expense or the recording of significant impairment losses could result from changes in the estimated useful lives of assets due to a number of reasons, such as excess aircraft capacity or changes in regulations governing the use of aircraft.

Aircraft and other long-lived assets are tested for impairment when circumstances indicate the carrying value of the assets may not be recoverable. To conduct impairment testing, the Company groups assets and liabilities at the lowest level for which identifiable cash flows are largely independent of cash flows of other assets and liabilities. For assets that are to be held and used, impairment is recognized when the estimated undiscounted cash flows associated with the asset group is less than the carrying value. If impairment exists, an adjustment is recorded to write the assets down to fair value, and a loss is recorded as the difference between the carrying value and fair value. Fair values are determined considering quoted market values, discounted cash flows or internal and external appraisals, as applicable. For assets held for sale, impairment is recognized when the fair value less the cost to sell the asset is less than the carrying value.

The Company’s accounting policy for major airframe and engine maintenance varies by subsidiary and aircraft type. The costs of airframe maintenance for Boeing 767-200 aircraft operated by ABX are expensed as they are incurred. The costs of major airframe maintenance for the Company's other aircraft are capitalized and amortized over the useful life of the overhaul. Many of the Company's General Electric CF6 engines that power the Boeing 767-200 aircraft are maintained under “power by the hour” and "power by the cycle" agreements with an engine maintenance provider. Further, in May 2017, the Company entered into similar maintenance agreements for certain General Electric CF6 engines that power many of the Company's Boeing 767-300 aircraft. Under these agreements, the engines are maintained by the service provider for a fixed fee per cycle and/or flight hour. As a result, the cost of maintenance for these engines is generally expensed as flights occur. Maintenance for the airlines’ other aircraft engines, including Boeing 767-300 and Boeing 757 aircraft, are typically contracted to service providers on a time and material basis and the costs of those engine overhauls are capitalized and amortized over the useful life of the overhaul.

In the event the Company leases aircraft from external lessors, the Company may be required to make periodic payments to the lessor under certain aircraft leases for future maintenance events such as engine overhauls and major airframe maintenance. Such payments are recorded as deposits until drawn for qualifying maintenance costs. The maintenance costs are expensed or capitalized in accordance with the airline's accounting policy for major airframe and engine maintenance. The Company evaluates at the balance sheet date, whether it is probable that an amount on deposit will be returned by the lessor to reimburse the costs of the maintenance activities. When an amount on deposit is less than probable of being returned, it is recognized as additional maintenance expense.

Capitalized Interest

Interest costs incurred while aircraft are being modified are capitalized as an additional cost of the aircraft until the date the asset is placed in service. Capitalized interest was $1.8 million, $1.3 million and $0.2 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Discontinued Operations

A business component whose operations are discontinued is reported as discontinued operations if the cash flows of the component have been eliminated from the ongoing operations of the Company and represents a strategic shift that had a major impact on the Company. The results of discontinued operations are aggregated and presented separately in the consolidated statements of operations.

Self-Insurance

The Company is self-insured for certain workers’ compensation, employee healthcare, automobile, aircraft, and general liability claims. The Company maintains excess claim coverage with common insurance carriers to mitigate its exposure to large claim losses. The Company records a liability for reported claims and an estimate for incurred claims that have not yet been reported. Accruals for these claims are estimated utilizing historical paid claims data and recent claims trends. Other liabilities included $18.4 million and $18.7 million at December 31, 2017 and December 31, 2016, respectively, for self-insured reserves. Changes in claim severity and frequency could result in actual claims being materially different than the costs accrued.

Pension and Post-Retirement Benefits

The funded status of any of the Company's defined benefits pension or post-retirement health care plan is the difference between the fair value of plan assets and the accumulated benefit obligations to plan participants. The over funded or underfunded status of a plan is reflected in the consolidated balance sheet as an asset for over funded plans, or as a liability for underfunded plans.

The funded status is ordinarily re-measured annually at year end using the fair value of plans assets, market based discount rates and actuarial assumptions. Changes in the funded status of the plans as a result of re-measuring plan assets and benefit obligations, are recorded to accumulated comprehensive loss and amortized into operating expense using a corridor approach. The Company's corridor approach amortizes variances in plan assets and benefit obligations that are a result of the previous measurement assumptions into earnings when the net deferred variances exceed 10% of the greater of the market value of plan assets or the benefit obligation at the beginning of the year. The amount in excess of the corridor is amortized over the average remaining service period to retirement date of active plan participants. Costs adjustments for plan amendments are also deferred and amortized over the expected working life or the life expectancy of plan participants. Irrevocable settlement transactions that relieve the Company from responsibilities of providing retiree benefits and significantly eliminate the Company's relate risk may result in recognition of gains or losses from accumulated other comprehensive loss.

Security and Maintenance Deposits

The Company's customer leases typically obligate the lessee to maintain the Company's aircraft in compliance with regulatory standards for flight and aircraft maintenance. The Company may require an aircraft lessee to pay a security deposit or provide a letter of credit until the expiration of the lease. Additionally, the Company's leases may require a lessee to make monthly payments toward future expenditures for scheduled heavy maintenance events. The Company records security and maintenance deposits in other liabilities. If a lease requires monthly maintenance payments, the Company is typically required to reimburse the lessee for costs they incur for scheduled heavy maintenance events after completion of the work and receipt of qualifying documentation. Reimbursements to the lessee are recorded against the previously paid maintenance deposits.

Income Taxes

Income taxes have been computed using the asset and liability method, under which deferred income taxes are provided for the temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities. Deferred taxes are measured using provisions of currently enacted tax laws. A valuation allowance against net deferred tax assets is recorded when it is more likely than not that such assets will not be fully realized. Tax credits are accounted for as a reduction of income taxes in the year in which the credit originates. All deferred income taxes are classified as noncurrent in the statement of financial position.

The Company recognizes the benefit of a tax position taken on a tax return, if that position is more likely than not of being sustained on audit, based on the technical merits of the position. An uncertain income tax position is not recognized if it has less than a 50% likelihood of being sustained. The Company recognizes interest and penalties accrued related to uncertain tax positions in operating expense.

Purchase of Common Stock

The Company's Board of Directors has authorized management to repurchase outstanding common stock of the Company from time to time on the open market or in privately negotiated transactions. The authorization does not require the Company to repurchase a specific number of shares and the Company may terminate the repurchase program at any time. Upon the retirement of common stock repurchased, the excess purchase price over the par value for retired shares of common stock is recorded to additional paid-in-capital.

Stock Warrants

The Company’s accounting for warrants issued to a lessee is determined in accordance with the financial reporting guidance for equity-based payments to non-employees and for financial instruments. The warrants issued to lessee are recorded as a lease incentive asset using their fair value at the time that the lessee has met its performance obligation. The lease incentive is amortized against revenues over the duration of related aircraft leases. The unexercised warrants are classified in liabilities and re-measured to fair value at the end of each reporting period, resulting in a non-operating gain or loss.

Comprehensive Income

Comprehensive income includes net earnings and other comprehensive income or loss. Other comprehensive income or loss results from certain changes in the Company’s liabilities for pension and other post-retirement benefits, gains and losses associated with interest rate hedging instruments and fluctuations in currency exchange rates related to the foreign affiliate.

Fair Value Information

Assets or liabilities that are required to be measured at fair value are reported using the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. FASB ASC Topic 820-10 Fair Value Measurements and Disclosures establishes three levels of input that may be used to measure fair value:


•	Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.


•	Level 2: Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.


•	Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include items where the determination of fair value requires significant management judgment or estimation.

Revenue Recognition

Aircraft lease revenues are recognized as operating lease revenues on a straight-line basis over the term of the applicable lease agreements. Revenues generated from airline service agreements are typically recognized based on hours flown or the amount of aircraft and crew resources provided during a reporting period. Certain agreements include provisions for incentive payments based upon on-time reliability. These incentives are typically measured on a monthly basis and recorded to revenue in the corresponding month earned. Revenues for operating expenses that are reimbursed through airline service agreements, including consumption of aircraft fuel, are generally recognized as the costs are incurred. Revenues from charter service agreements are recognized on scheduled and non-scheduled flights when the specific flight has been completed. Revenues from the sale of aircraft parts and engines are recognized when the parts are delivered. Revenues earned and expenses incurred in providing aircraft-related maintenance, repair or modification services are usually recognized in the period in which the services are completed and delivered to the customer. Revenues derived from sorting parcels are recognized in the reporting period in which the services are performed. Revenue is not recognized until collectibility is reasonably assured.

Accounting Standards Updates

In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” ("Topic 606”) to supersede existing revenue recognition guidance. During 2016, the FASB issued additional ASU's to further amend the new revenue recognition guidance. Topic 606 is a comprehensive new revenue recognition model that requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. Topic 606 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and about assets recognized for costs incurred to obtain or fulfill a contract.

The new revenue recognition standards are effective for annual reporting periods beginning after December 15, 2017 with earlier adoption permitted for reporting periods beginning after December 15, 2016. Topic 606 may be adopted using either a full retrospective approach, under which all years included in the financial statements will be presented under the revised guidance, or a modified retrospective approach, under which financial statements will be prepared under the revised guidance for the year of adoption, but not for prior years. Under the latter method, entities recognize a cumulative catch-up adjustment to the opening balance of retained earnings at the effective date for open contract performance at that time. The Company is adopting the standard effective January 1, 2018, using the modified retrospective method.

The Company's adoption efforts have included the identification of revenue within the scope of the standard, the evaluation of customer contracts in conjunction with new guidance and an assessment of the qualitative and quantitative impacts of the new standard on its financial statements. The evaluation included the application of each of the five steps identified in the Topic 606 revenue recognition model.

The Company determined that under Topic 606, it is an agent for aircraft fuel and certain other costs reimbursed by customers under its ACMI and CMI contracts and for certain cargo handling services that it arranges for a customer. Under the new revenue standard, such reimbursed amounts will be reported net of the corresponding expenses beginning in 2018. This application of Topic 606 will not have an impact on the Company's reported earnings in any period. Additionally under Topic 606, the Company will be required to record revenue over time, instead of at the time of completion, for certain customer contracts for airframe and modification services that do not have an alternative use and for which the Company has an enforceable right to payment during the service cycle. The Company is adopting the provisions of this new standard using the modified retrospective method which requires the Company to record a one time adjustment to retained deficit for the cumulative effect that the standard has on open contracts at the time of adoption. The Company estimates that upon adoption of the new standard, it will accelerate approximately $3.6 million of revenue resulting in immaterial adjustment to its January 1, 2018 retained deficit for open airframe and modification services contracts. The Company's lease revenues within the scope of ASC 840, Leases, are specifically excluded from Topic 606.

In February 2016, the FASB issued ASU "Leases (Topic 842)" ("ASU 2016-02"), which will require the recognition of right to-use-assets and lease liabilities for leases previously classified as operating leases by lessees. The standard will take effect for annual reporting periods beginning after December 15, 2018, including interim reporting periods. Early application will be permitted for all entities. In addition, the FASB has decided to require a lessee to apply a modified retrospective transition approach for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements (the date of initial application). The modified retrospective approach would not require any transition accounting for leases that expired before the date of initial application. The Company is currently evaluating the impact of the standard on its financial statements and disclosures.

In January 2017, the FASB issued ASU "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment" ("ASU 2017-04"). ASU 2017-04 will simplify the subsequent measurement of goodwill by eliminating the second step from the goodwill impairment test. ASU 2017-04 would require applying a one-step quantitative test and recording the amount of goodwill impairment as the excess of the reporting unit's carrying value over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. ASU 2017-04 does not amend the optional qualitative assessment of goodwill impairment. The amendments in ASU 2017-04 are effective for annual or any interim goodwill impairment tests for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not expect the new standard to have a material impact on its financial statements and disclosures.

In March 2017, the FASB issued ASU "Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost "(ASU 2017-07"). ASU 2017-07 requires an employer to report the service cost component of retiree benefits in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented separately from the service cost component and outside a subtotal of income from operations. ASU 2017-07 is effective for years, and interim periods within those years, beginning after December 15, 2017, and requires retrospective application to all periods presented. This ASU will impact the Company's Operating Income subtotal as reported in the Company's Consolidated Statement of Operations by excluding interest expense, investment returns, settlements and other non-service cost components of retiree benefit expenses. Information about interest expense, investment returns and other components of retiree benefit expenses can be found in Note I.

In February 2018, the FASB issued ASU “Reclassification of Certain Tax Effects From Accumulated Other Comprehensive Income" ("ASU 2018-02"). ASU 2018-02 amends ASC 220, Income Statement — Reporting Comprehensive Income, to allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from U.S. federal tax legislation known as the Tax Cuts and Jobs Act. In addition, under the ASU 2018-02, a Company will be required to provide certain disclosures regarding stranded tax effects. ASU 2018-02 is effective for years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact of the standard on its financial statements and disclosures