Expense for airline miles?

[bwells7]

Foreign mission trip and traveled by airline not vehicle.

[SusanY1]

If the trip qualifies as a charitable endeavor for a qualified organization, you may be able to deduct the cost you paid for airfare.  

You would enter the amount paid as a charitable contribution, rather than entering miles traveled for charitable purposes. 

Miles for charitable purposes would include things like the miles driven to provide volunteer services or to deliver charitable donations.