Keep in mind that the only thing for which this rate may be used is determining the maximum rate you can claim for reimbursement for travel by private aircraft on Federal government business. You are not permitted to use it for Federal income tax purposes, even for determining whether you were over-reimbursed (in which case you'd owe taxes for that extra income) or under-reimbursed (in which case you can deduct the difference as unreimbursed business expense) for such travel. For IRS purposes, you must be able to document the actual cost of the aircraft, either by rental invoices or records of expenses/hours for your own aircraft.
And yes, this has been confirmed with the IRS, AOPA's legal eagles, and two independent tax professionals.
