The leather jacket Jimmy Garret wears is actually a Navy G-1 flight jacket worn by Navy aircrew. The Air Force did not begin issuing leather flying jackets to aircrew (theirs, being the A-2) until 1988, one year after the release of this film.
As Virgil is taxiing the O-2 toward the runway the AP radios airport security that the aircraft is headed down taxiway 3. At all airports taxiways are lettered, not numbered. Numbers are used only for runways.