Property & Equipment – Property and equipment are recorded at cost or fair value on the date of acquisition and depreciated, when the asset is ready for its intended use, on a straight-line basis to an estimated residual value over their estimated useful lives or lease term (if applicable), whichever is shorter, as follows:
Airframes (1)
10-25 years (depending on age)
Engines – Core (2)
7 or 12 years (based on remaining cycles)
Engines – Initial Greentime (time remaining until the first scheduled major maintenance event)
1st scheduled maintenance event
Leasehold Improvements, Aircraft, Other
3-25 years (or life of lease, if shorter)
Office and Ground Equipment
5-7 years
Computer Hardware and Software
3-5 years
Property and Equipment under Finance Leases (3)
Lesser of the lease term or economic life
Rotable Parts
Average remaining life of aircraft fleet, currently estimated to be 8 years
_____________________________
(1)
Airframes have an estimated residual value of $4,000.
(2)
Engines - Core have an estimated residual value of $1,500.
(3)For finance leases where the Company is reasonably certain to exercise the purchase option, the lease asset value is assigned to the engine and airframe components which are depreciated on a straight-line basis in accordance with the useful lives outlined in the table above.

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.