The continuing adventures of Alley Oop have him brawling with his ex-friend on the back of a flying pteranodon (the narrator refers to it as a pterodactyl, but it is way too large to be a pterodactyl). Any combat that takes place on a moving animal's back, moving vehicle, or some other terrain where balance comes into play should require a save vs. science from each participant per turn to keep from falling.
According to Alley Oop, pteranodons must have a low Armor Class from frontal attacks because their beaks are so hard (or Alley is just griping because his attack rolls have all been so bad).
As for that antique plane...even I wouldn't be mean enough to give my players transportation that antiquated...
(Scans courtesy of Comic Book Plus)