There have been a number of controversies with administration officials flying on private or charter flights while conducting government business. Don’t try this with your federal grants. If you want to fly on chartered aircraft, you can BUT your grant cannot pay for the entire cost. You can charge your grant up to the price of an unrestricted coach fare per person; your organization is then responsible for the difference between the unrestricted coach fare and the cost of the charter price (assuming the charter is more expensive). If you do what the political appointees are doing, your organization will be on the hook to write a big reimbursement check to Uncle Sam.