Recent Revenues and Depreciation for Delta Airlines Inc. (DAL)

Airlines are excellent examples because they have massive investments in long-lived, tangible assets, primarily aircraft, that are subject to depreciation.

DAL's depreciation and amortization expenses have remained relatively stable between $1.7B to $2.5B (the vast majority of which is depreciation), reflecting the airline's continued investment in its fleet despite revenue fluctuations. These expenses reduce Delta's reported operating income and, ultimately, its net income (profit).