Factual error: The German fighters depicted in the film are Messerchmitt Bf 109 G-6s, and every single one of them is using the Rüstsatz VI gun pod, that is, 2 extra 20mm Mg 151 cannons. The Luftwaffe only equipped their Bf 109s with the gun pods when they were going to intercept bombers. In this movie, even on the fighter vs fighter missions, they have these gun pods, which is inaccurate, because the gun pods dramatically reduced the turning performance of the Bf 109s.
Factual error: Me 262's were armed with 30 mm cannon in the nose, a round penetrating a canopy would leave a hole much larger than was depicted, and being high-explosive, once it detonated inside the cockpit, the pilot was toast. One of the red tails had a number of holes in his canopy.
Suggested correction: Reports suggest twenty mm cannon fire through the canopy will not inherently detonate and can pierce through. The 30 mm of the particular enemy craft however may be unique enough to differ, but is ambiguous then for now until someone finds new data. As for size, keep in mind the nature of how penetration does not look right and I believe care to not exaggerate the size not be taken. Personally am not aware of comparison enough to inform on true size.
Factual error: Before receiving the North American P-51D Mustangs, the Red Tail squadron was using the Curtiss P-40E Warhawk. The movie shows the Warhawks being able to keep up with the German Bf 109 G-6s quite easily, fighting on even terms. In reality, the Bf 109 G-6 could easily outperform the Warhawk, being able to easily outrun and out-turn the Warhawk. Still, the Bf 109s are no match for the Warhawks.
Factual error: When the German fighters are on the ground at the airfield the fighters have a yellow belly band, which was only on Russian front aircraft. German planes in Italy had white belly bands and white wing tips.
Factual error: The German fighters in the movie are Bf 109 G-6s, which are armed with 2 13.2mm Mg 131 machine guns and one 20mm Mg 151 cannon, but they are shown equipped with the Rüstsatz VI gun pods in the wings, which are 2 extra Mg 151s. That is a very heavy armament, capable of shooting down even a Boeing B-17 Flying Fortress quickly. Still, the Mustangs and Warhawks used by the Red Tails are shown taking lots of hits and still flying with relative ease. The P-51D Mustang and the P-40E Warhawk were indeed quite rugged and damage resistant, but 3 20mm cannons and 2 13.2mm machine guns are more than enough to shoot them down with even a 1 second burst.
Factual error: When the German fighter ace (called "Pretty Boy" by the Tuskegee Airmen) attacks the B-17s, he says "Brecht ein und zieht die Kämpfer ab!" What he wanted to say is "Break through and distract the fighters" but his choice of words is more like "Break in (as break into) and pull (draw) the fighters off!"
Continuity mistake: The scene shot when Lt. "Lightning" Little first goes to meet Sophia was also shot at the same time as when Capt. "Easy" Julian arrives to tell Sophia of Lightning's death. The jeep is the same jeep, parked in the same exact spot; even the laundry on the line is exactly the same. (00:23:05 - 01:56:00)
Factual error: General Luntz states that an upcoming raid would be the "first against Berlin". Actually the first US raid against Berlin was early in 1944, before the 332nd was involved in bomber escort duties.
Continuity mistake: When Lightning drives off to meet with Sophia for the first time, he gets into a Jeep with the number 20860779, but when he arrives at Sophia's house, the Jeep has the number 20207765.
Factual error: When Lightning returns to base following the destruction of the train, the pilots watch his gun camera films. Gun cameras are trained forward of the aircraft, while some of the footage displayed was from behind the P-40.
Factual error: Early in the film, a P-40 is tracked in camera nearing its touchdown on the landing strip. You can see the landing flaps down. The error is in showing plain flaps down. P-40s featured split flaps, not plain flaps.
Continuity mistake: The red tail pilot parachutes into snow, but when shown from above there is no sign of snow.
Factual error: The markings on all German fighters in this movie are completely wrong or fictitious. Worst offender is the "Pretty boy" BF 109 with the yellow markings. Everything is non-standard, including the swastika on the tail. On top there is a SS-decal "Death's head" on the engine cowl. No Luftwaffe planes carried SS-markings. This is just some Hollywood-styling.
