broadsword
Brigadier
It is now a 20 year question.
China's transport, tanker & heavy lift aircraft - esp. Y-20/YY-20
- Thread starter Totoro
- Start date
It is now a 20 year question.
that's Il-76 test bed, been that way for a while now. WS-20 might still have some bugs that needs to be fixed , it's better to have one thing that's new and might cause weird problem rather than having a whole bunch of things that's new and impossible to pin down an issue.
Verum
Junior Member
It's easier said than done to fit new engines to a plane. Military transport planes might be not as sensitive to engine changes as small fighter jets, but it does change the air frame layout and the aerodynamic efficiency. It does take a lot of effort to achieve it.
It's kind of a pain in the ass to develop a brand new plane on an old engine and a new engine on an old airframe, then spend another year or two to merge the two together. But oh well, that's the best they could do in their situation.
It's kind of a pain in the ass to develop a brand new plane on an old engine and a new engine on an old airframe, then spend another year or two to merge the two together. But oh well, that's the best they could do in their situation.
Re engining something like a large transport would probably be less difficult than re engining a fighter, not only due to structural reasons, but performance reasons.
It would also be prudent for the designers to have foreseen the need to re engine the prototypes from an older engine to a newer one and have pre prepared methods to expedite any engine exchange.
Of course, it obviously won't be plug and play, but it won't need the coupe of years of testing required when re engining a high performance fighter either.
It would also be prudent for the designers to have foreseen the need to re engine the prototypes from an older engine to a newer one and have pre prepared methods to expedite any engine exchange.
Of course, it obviously won't be plug and play, but it won't need the coupe of years of testing required when re engining a high performance fighter either.
Au contraire, what we see with commercial wide bodies is that it is in fact pretty close to plug and play
Au contraire, what we see with commercial wide bodies is that it is in fact pretty close to plug and play
I err on the side of cautiousness
Verum
Junior Member
Military transport planes and commercial airliners are very different, especially in the case of fitting engines.
Commercial airliner engines are very comparable to each other, most are designed to fit onto the similar airframes in the same weight class. They usually have very similar performances and aerodynamic layout, they are designed to be plug and play. Even if they have differences, it's very minimal, more like the different engines in the VW family, very easily mounted onto another VW car.
On the other hand, military planes are highly specialized, especially when it's a generation changing engine, low-by-pass to high-by-pass, also a very very different aero layout. That's like switching a high revving sportscar engine with a low rev high torque diesel truck engine. Of course, the big wing span and low top speed would guarantee the plane to not fall out of the sky with new engine and no aero modifications, but to get the optimal performance and efficiency, modifications are needed, and it would take a long time, say at least 1 to 3 years.
Commercial airliner engines are very comparable to each other, most are designed to fit onto the similar airframes in the same weight class. They usually have very similar performances and aerodynamic layout, they are designed to be plug and play. Even if they have differences, it's very minimal, more like the different engines in the VW family, very easily mounted onto another VW car.
On the other hand, military planes are highly specialized, especially when it's a generation changing engine, low-by-pass to high-by-pass, also a very very different aero layout. That's like switching a high revving sportscar engine with a low rev high torque diesel truck engine. Of course, the big wing span and low top speed would guarantee the plane to not fall out of the sky with new engine and no aero modifications, but to get the optimal performance and efficiency, modifications are needed, and it would take a long time, say at least 1 to 3 years.
SamuraiBlue
Captain
And yet Kawasaki C-2 is fitted with GE CF6-80C2 which is a very popular jet fan engine used on various commercial aircraft from Boeing 747s to Airbus A310s .
I agree with your hypothesis on fighter jets but for transport no I don't think so.
Verum
Junior Member
What did I say about using commercial engines on military aircrafts? Nothing. All I was saying was that military aircrafts are not so interchangeable with engines compared to commercial aircrafts. Kawasaki C2 was designed with CF6 since the beginning.
Military cargo planes can use whatever engines can be mounted, it could even fly with J7 engines if you strap eight of them on the wings (albeit not perform so well). But what I was saying was that to fit new engines and to get the best performance and efficiency out of it, you have to modify aero layout and flight control system to some extent. Of course, when you have a slow flying whale with giant wings, anything can make it fly, but it's a lot harder than to be said than done to make it top class.
That's why it would take at least couple of years to get it right.
I know several years sounds like a long time, but when you factor in the human aspect, such as holidays and paternal leaves; and project aspects like bottlenecks, supplier missing dates, test flight accidents, all these could easily make a project drag longer than it was originally planned.
If you want examples, just look at J-10B. Fundamentally it's the same plane as J-10A, even the engines are the same. The only upgrades are the air intakes and avionics. J-10A matured for a decade already and yet J-10B still hasn't officially entered service. If it was so easy, we would have 20th generation fighter jet by now, instead of the current 4th gen J-20 and F22.