Howard Lydecker and Theodore Lydecker, Republic Pictures' special effects wizards, shot all outdoor effects shots around Santa Fe, New Mexico, in order to take advantage of the impressive cloud formations.
Theodore Lydecker claimed that no actual aircraft were used in this movie, with the effects being created by Republic Pictures' 15-man special effects department, headed by he and his brother Howard Lydecker.
In 1949, Republic Pictures reissued this film on a double bill with The Fighting Seabees.
No scene of the interior of the airplane could be shown for security reasons. The instrument boards shown were fake.
Some clips of the dogfights and Japanese ack-ack guns were from confiscated Japanese newsreels.
The airplanes seen on the ground in the film are decommissioned P-40Bs, of the type actually used by the American Volunteer Group in China; they have four prominent gunports on the engine cowling (but no guns.) In the aerial sequences the planes are 1941 P-40E's, with six wing-mounted guns and a smooth cowling.
The Flying Tigers' planes were full-size mock-ups made mostly of plywood and balsa wood, not - as has often been thought - real aircraft. The "engine" noises were sound effects added after production.
The opening scene shows a Japanese air raid and in the aftermath a crying child is sitting alone amid debris. This scene virtually duplicates a famous photo taken in 1937 and published in Life magazine following a Japanese air raid on Shanghai. (Located in the National Archives, ARC Identifier: 535557)
This film's opening prologue is a quote from Kai-Shek Chiang. It states: "Since the Flying Tigers first spread their wings in the skies above China, the enemy learned to fear the intrepid spirit they have displayed in face of his superior numbers. They have become the symbol of the invincible strength of the forces now upholding the cause of justice and humanity. The Chinese people will preserve forever the memory of their glorious achievements." 'Generalissimo Chiang Kai-Shek'
This movie broke all boxoffice records for Republic Pictures by a large margin and was one of the top grossing movies of the year.
When John Carroll was introduced to a Tiger from Texas, he inquires, "Do you know the McNaught Sisters in Fort Worth?" This was an inside joke by screenwriter Barry Trivers. The McNaught Sisters - Mary, Ruth and Corinne - were actually from Fort Worth and were cousins of Florine McKinney, Trivers' former wife.