The estimated useful lives of property and equipment are as follows:
 Estimated Useful Life (in years)
Aircraft, spare engines and related rotable parts
25 to 30
Aircraft seats
10 to 15
Buildings
25 to 45
Other property and equipment
3 to 20
Computer software
5 to 15
Building improvements
1 to 40
Operating property and equipment, net at December 31 was as follows (in millions):
20252024
Flight equipment$56,876 $52,696 
Other property and equipment13,204 11,908 
Purchase deposits for flight equipment3,506 3,427 
Total operating property and equipment73,586 68,031 
Less—Accumulated depreciation and amortization(27,466)(25,123)
Total operating property and equipment, net$46,121 $42,908 

Historical Timeline

Fiscal YearFiled
2025Feb 12, 2026Showing above
2017Feb 22, 2018

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.