Hi Siegfried
I suspect that the extra hassle of more turbine stages, reducer gearboxes, complicated control systems make the turbo-prop a non starter for combat aircraft. Niches remain such as STOL but for military struggling to obtain the upper hand they may as well use their highly developed piston engines on transports and maritime patrol aircraft while the combat aircraft use turbojets.
I take it by this you mean during WW2? If you do, no working turboprop had been fitted to an aircraft; the first aircraft to be powered by a turboprop was a Gloster Meteor EE227 especially modified with a reduction gearbox fitted to its engine; this was the RR Trent RB.50 torboprop fitted with a Rotol constant speed propeller. it first flew as a turboprop in September 1945.
If you don't, you need to look at a military aircraft directory. Turbo-props have powered all manner of combat aircraft; the Westland Wyvern torpedo bomber, the Fairey Gannet maritime patrol aircraft to name a couple. These days no one but poorer military nations operate piston engined transport and maritime patrol aircraft. (The RAAF have since retired the Caribou, but then you would know that being in Australia) The only MP aircraft in service today that is not a turboprop is the Nimrod, which is powered by four RR Conway low bypass turbofans. By the way, with the exception of designs over forty years old, no combat aircraft are powered by turbojets today; all turbofans.
Even in the range area the turbo-prop offers little advantage in long flights.
Not strictly true! I suspect the designers and operators of the P-3 Orion might disagree. If you are comparing this to current gas turbine technology as applied to the likes of RR Trent 1000 and GENx engines, then, yes. Turboprop powered aircraft demonstrate remarkable efficiency and range for their size and load carrying capability. Do you know much about the ATR-72 regional airliner? This has remarkably low fuel consumption and a long range carrying nearly 20 more passengers than the Dash Eight Q300 on roughly the same powerplant.
Turboprops are no more complex in design that modern pure jet engines. How much do you know about the PWC PT-6 turboprop? It and many other turbo props still use centrifugal compressors due to their simplicity and robustness. Modern high bypass turbofans demonstrate a degree of complexity that exceeds the average humble turboprop. Sure, there is a reduction gearbox, but piston engined aircraft were also fitted with such things, since before WW1. This was not new technology with the introduction of gas turbine driven propellers. This suggestion that turboprops have more turbine stages than a pure jet is rubbish. in the PW100 series turboprop there are three turbine stages. In the RR Trent 900 fitted to the A380 there are seven turbine stages. I could go on about the inaccuracy of your post, but I won't.
Might I suggest we return to the topic of the thread, please?