The jet engined He-176 first flew in 1939; even the British Gloster-Whittle E.28/39 was successfully flown on May 15, 1941.
It'd be even more interesting if Hitler's panzer troops had been used on the British forces struggling to evacuate at Dieppe, buying the Germans somewhere between six more months to two more years for development of their air war Vergeltungswaffen.
That, and a more successful U-boat campaign not depending on the penetrated Enigma coding device, could have made things particularly dicy for the Brits...and forestalled the use of Britain for any Allied pre-Eorope invasion plans.
The first test of a jet-driven airplane took place at Rechlin on July 3, 1939, when test pilot Erich Warsitz flew the Heinkel He-176 jet plane for Hitler, Goring, Udet, and the entire Luftwaffe High Command. The test went swimminglyso well, in fact, that the Nazi hierarchy thought the device was a hoax or a joke.As it was:When Warsitz landed perfectly and climbed out of the aircraft beaming, Hitler and the generals looked at him stone-faced, turned on their heels and left. The Luftwaffe, Heinkel understood, was not inclined to sponsor further research. (Heinkel and Messerschmitt, both astute judges of technology, pursued the research on their own.)
What might have been:
The missed opportunities of history fascinate me. "For want of a nail the shoe was lost" etc.
I think you must mean they should have use the tanks to stop the evacuation of Dunkirk, not Dieppe. Dieppe was an outright slaughter of mostly Canadians, when the allies made a test case out of an attempted landing to see what would work for the eventual assault on Fortress Europe.