Goofs

Jimmy is shown shooting down what is obviously intended to be a Junkers Ju 87 - but the aircraft then seen, in a well-known piece of stock footage, to crash into the sea is a Westland Lysander (British).

When Rog crashes, the aircraft which hits the ground is clearly different from the pseudo-Spitfire he was flying immediately before impact (eg trousered undercarriage, radial engine).

After Jimmy's bombing, several Junker Ju 87s are sent up to catch him. This wasn't their role, nor could they possible catch a Spitfire.

In the London air-raid, the first 'German' bomber shown (in plan silhouette) looks like a Vickers Wellington (British).

During combat scenes shot using models, the aircraft make turns so tight that - if real - their wings would rip off and their pilots would black-out.

The aircraft in Jimmy's initial diving test-flight appears to be invented - based on a Ryan ST-A trainer but with single cockpit and different undercarriage (retractable evidently, as it's not seen until landing, even though then it looks fixed), and the model used for flight scenes is duplicated at full size for taxiing scenes. Because of its its vague similarity to a Spitfire (similar in fin shape but obviously wrong in fixed undercarriage, externally-braced wing, shape of engine cowling, canopy and rear fuselage, cockpit too far back, lack of armoured cockpit glass, parallel leading- and trailing-edges of wing) similar full-size models in RAF colours seem to have been used for static and taxiiing scenes of Spitfires, and miniatures of this invented type are used for flight scenes (as well as stock footage of real Spitfires).

In Jimmy's final bombing operation (in which his single early-mark Spitfire effects more bomb-damage than many bombers would have been happy to manage), the target is said to be only 40 miles from his UK base. Difficult to think where such a major target could be.