I know that that some people who didn't read this properly are going to VTCThough it may sound similar, this asis not a duplicate of this. But theThe core difference is that the question there of that is limiting the development of all aircraft, but this is about limiting development of specifically jet aircraft. Because my goal is for there to be a few more generations of high performance propeller aircraft, not just for planes to be less effective overall.
The aim is to make it so that jet aircraft only become dominant around 1959-1961, so that high performance prop planes are still dominant in the air later for a few more generations. I don't mind if there's an in between generation of mixed power or turboprop aircraft or jet aircraft are still around, only that some kind of propeller aircraft remain the primary way of fighting in the air into the late 1950s.
Note that piston aircraft cannot be heavily delayed as a side effect of this, because that would defeat the entire point of trying to make high performance prop planes last longer. Piston engine helicopters like the CH-37 or H-34 shouldn't be heavily delayed either, although i don't mind if gas turbine helicopters are delayed.