Blooper

When Scotty and Big Mike take off for Asia over the hump, they're in a Douglas C-47. Upon arrival it shows a Curtiss C-46 coming in for final and then finally another shot of a different C-47 landing.

The Japanese radio announcer makes multiple references to the "Imperial Japanese Air Force". There was no such component of the Japanese military - the Japanese Army and Navy each had an air arm (and if the enemy fighters were Zeroes, they would have been flown by Naval aviators.)

After Scott arrives in Kunming, one of the Tigers refers to his aircraft as a DC-3. In reality he would have called it a C-47; DC-3 was the civilian designation for the airplane.

The P-43 Lancer that Scott is flying with Big Mike was a single seat aircraft with the bulkhead directly behind the pilot with no room for even a make shift spot for a passenger.

The P-40s taking off for the raid at the end of the film have empty racks where the external fuel tanks should be attached. Such a long-range mission would require auxiliary tanks.

After crossing the hump, Scott tells the sergeant to go back and inform the others that oxygen masks are no longer required. The sergeant walks back without disconnecting his mask from anything and the hose can be seen to be going onto his pocket.

The B-25s used are G models, which were not introduced until mid-1943. The raids in the film take place in summer 1942.

When Scott is taking off from Kelly Field in San Antonio, Texas, a mountain can be seen in the background. No such mountains exist around San Antonio.