Much appreciated
can you also give us a perspective on military turbofan testing campaign? by that I mean, assume the company has designed and built the first prototype and we fired the engine the first time. Between the first firing and delivery into service, what percentage of engineering hours are spent on which phase of the testing? Is reaching the rated thrust take the bulk of the work? I asked some LLMs how much time do turbofan manufacturers take to reach the engine's thrust target and the answers were all over the place. Obviously, I ask these questions in context of TF6000 and TF35k and I know the technological readiness of TEI and the GE, RR etc. vastly different but i just wanna gain some perspective on the problem and not get lost in the never-ending speculations.
It is pretty hard to put numbers to this. The commercial domain is more transparent one given the economies of scale (MRO workshops etc and raw number of flight hours daily compared to all airforces put together in a year etc).
Think about China for example in its ferrari vs corolla ecosystem here (military vs commercial)....given the progress in WS military turbofans since this century start (from the 80s,90s the base a mix of soviet and western).
Commercial will be more transparent to track and measure: COMAC with LEAP vs domestic equivalent over next 20 years etc... it boils down to total capital (old, current, new...machinery, innovation, experience) leverage and inertias between China and Western one.
Military one is far more non-transparent. There could be lot of "good enough" and produce twice engines (have a spare etc) in raw way to handle MTBO issues (costs are not an issue) But there is a hit in the intermediate overhauls (needed...or reliability impact from it being foregone) along the way too. This is what any airforce + relative def. establishment wouldn't advertise when it makes compromise to get the base indigenous "start" squared away however it deems to.
Other allied airforces (to PRC) also keep close to chest etc...and then its up to whomever regd how much we by and large accept everything face value past that. No airforce is going to large scale operate both and release both data streams transparently in some way etc.
i.e similar reason Russian (Soviet) military turbofans only had so much impact on commercial international domain. Capital conversion from one to the other was limited in end....from that we can adjudge the military one was not/is qualitatively the same as western peer either.
What I can tell you though is engine reliability + efficiency (it is hard to separate these neatly) in the commercial domain is like a 80% design time + cost thing. Maybe higher than that. GE going for detailed design in lubricating oil lines compared to Pratt (which felt more promise in geared turbofan to deploy capital there) for the 1% improvements that add up in savings etc. These things dont really enter the military domain. This is from the basic "thrust" design long being settled in 20th century....i.e we have iterative means only now to get closer to carnot peak.
If a miltary (Soviet, Russian, Chinese) wants to simply get 1000 "good enough" out there for warplanes and take some hit on that, you can maybe reduce to 50 - 50.
I doubt these days its going to go much lower than that, there is simply much more other capital locked into each military jet (radars, missiles, sensors, integration) these days to be chokepointed by the powerplant reliability. i.e the Mig-21 model is not there anymore anywhere.
So in end it depends on Turkish airforce top decision makers (when it comes to engineering) and how TEI works with capital they got at hand.
