[George Hopp]

Since the pistol would normally be under the pilot's jacket, it would bulk out the jacket somewhat but otherwise shouldn't impede his exit from the aircraft. Remember the same person also had a parachute harness, and either seat or back parachute, and depending on where he was flying, a life jacket also. So, I imagine the pistol would simply be tucked in somewhere where it wouldn't interfere with anything else on the pilot (or other crew) and that would be it.

I don't know about other services, but in the RCAF, aircrew seem to have been given a choice of whether or not to carry guns. Most often they didn't because they might shoot themselves, and it might give the Germans extra incentive to shoot them. As an infantry friend said about pistols: "The best way to hit someone with a pistol is to throw it at him."