Congress has chosen to allow taxpayers to write off the cost of their aircraft on an accelerated basis.  Business aircraft used for private purposes (non-commercial) can be depreciated using 5-year MACRS rates providing they meet certain requirements.  The rapid tax depreciation provides significant after-tax cash flow.  From time to time, as is the case now, Congress allows taxpayers additional accelerated depreciation in the form of special 50% bonus depreciation for new business aircraft.