[Six Nifty .50s]

I know that dive angles vary according to the chart but I also know that at lower heights there were greater limits on dive speeds, especially if the angle was 45 degrees or more. The pilot could tear the wings or tail off the aircraft and many Spitfires were structurally damaged when pulling out from dive-bombing runs.

There is a good reason why Martindale dived his Spitfire from 40,500 feet. If the Spitfire could be safely dived from a 45 degree angle at a speed substantially greater than .67 Mach (when below 19,500 feet) I don't think it's unreasonable to demand some proof.