Only example I can think of recently was when a certain Tonka pilot took his 'Jedi' brother for a ride down Scotlands 'Star Wars Valley' and that was done as a
PR/Charity trip.I believe the pilot has now left the services though.
Only other one I can think of were a Father/Son Buccaneer trip many eons ago.Father was a serving pilot,son was a serving Nav so I don't think that counts.