With year-end approaching, companies may want to review their use of business aircraft during this tax year in the context of significant applicable tax provisions. These provisions include rules relating to (1) imputing income to employees for personal use of aircraft, (2) deduction disallowances for entertainment use of aircraft by specified individuals, employee commuting expenses and failure to adequately substantiate expenses, (3) meeting the Section 280F qualified business use test for depreciation purposes and (4) claiming bonus depreciation. Failure to apply the rules properly may adversely impact both employers and their employees.