(in millions)
20252024
Property and Equipment
Aircraft and other flight equipment$13,647 $12,273 
Other property and equipment2,424 2,173 
Deposits for future flight equipment731 883 
Less: Accumulated depreciation and amortization(4,945)(4,548)
Total Property and Equipment, net$11,857 $10,781 
Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives less an estimated salvage value, which are as follows:
Estimated Useful LifeEstimated Salvage Value
Aircraft and other flight equipment: 
Boeing 717-200 aircraft
3 to 4 years(a)
10%
Boeing 737 aircraft
20 to 25 years
10%
Boeing 787-9 aircraft
25 years
10%
Airbus A321neo aircraft
18 to 20 years(a)
10%
Airbus A330 aircraft
11 to 15 years(a)
10%
Embraer E175 aircraft
20 years
10%
Buildings
30 to 40 years
10%
Minor building and land improvements
10 years
—%
Capitalized leases and leasehold improvementsGenerally shorter of lease term or
estimated useful life
—%
Computer hardware and software
3 to 5 years
—%
Other furniture and equipment
3 to 10 years
—%
(a) Based on remaining useful life as of September 18, 2024, the date of the Hawaiian acquisition and when the fair value of acquired aircraft was remeasured.

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.