J-20 5th Gen Fighter Thread VI

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Hendrik_2000

Hendrik_2000

Lieutenant General
TerraN_EmpirE said:
My point was you don’t just build it fuel it and have a pilot jump in the cockpit for a flight.

J20 took a full 3 Months to go from Taxi tests to first flight. And there was a period of time between roll out of the first prototype and first taxi.
So Years is not unheard of. Even for just an Engine testing. Military aircraft and major components are expected to perform in a extreme number of environmental conditions and situations and have to be certified to those.
And as Stated this is a Rumor and rumors need not be true.
Click to expand...

But they do have sophisticated all weather and all season with attitude simulation room now that can simulate all kind of weather and all kind of attitude. The can extensively test is there first
before going to test plane
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
At the hear of what I am trying to say is hold your horses. Slow down lead foot. This isn’t as simple as plugging a brand new Keyboard into your tablet computer.
Can you simulate environmental conditions for the engine alone? Yes
But you need to know how the engine and the aircraft react to each other, these are two complex components that work in a symbiotic relationship. So back to the test chambers again.

Yet once that is down before taxi, because this is a modern fighter with a modern engine you need the software. Depending on if it was a Russian or Chinese made Flanker you could have very different core computers and Software. Even if they are both Chinese
Software encoding in Aviation can take a long time with modern aviation hardware and is an absolutely critical aspect. You need the Fly by wire system and the FADEC to be able to understand each other. Since this is a prototype that means custom designed software. Coding of the two can take time. A lot of time. Even if it not as long as the lines of code for a Tesla.
Look at Boeing’s 737-Max right now. That’s a Software issue that has grounded those birds for how long now? 6 Months and counting with estimates pushing to December or next year.
Or the F35 vs F16 test from a few years ago where an early very restricted version of the software in the FBW limited the ability of the test bird to keep up.

So yeah it can take months or years.
And if that came if as Snide I apologize.
 
ZeEa5KPul

ZeEa5KPul

Colonel
Registered Member
TerraN_EmpirE said:
At the hear of what I am trying to say is hold your horses. Slow down lead foot. This isn’t as simple as plugging a brand new Keyboard into your tablet computer.
Can you simulate environmental conditions for the engine alone? Yes
But you need to know how the engine and the aircraft react to each other, these are two complex components that work in a symbiotic relationship. So back to the test chambers again.

Yet once that is down before taxi, because this is a modern fighter with a modern engine you need the software. Depending on if it was a Russian or Chinese made Flanker you could have very different core computers and Software. Even if they are both Chinese
Software encoding in Aviation can take a long time with modern aviation hardware and is an absolutely critical aspect. You need the Fly by wire system and the FADEC to be able to understand each other. Since this is a prototype that means custom designed software. Coding of the two can take time. A lot of time. Even if it not as long as the lines of code for a Tesla.
Look at Boeing’s 737-Max right now. That’s a Software issue that has grounded those birds for how long now? 6 Months and counting with estimates pushing to December or next year.
Or the F35 vs F16 test from a few years ago where an early very restricted version of the software in the FBW limited the ability of the test bird to keep up.

So yeah it can take months or years.
And if that came if as Snide I apologize.
Click to expand...
If it's this complicated why test the WS-15 on a Flanker to begin with? Why not test it on a J-20 directly?
 
TerraN_EmpirE

TerraN_EmpirE

Tyrant King
ZeEa5KPul said:
If it's this complicated why test the WS-15 on a Flanker to begin with? Why not test it on a J-20 directly?
Click to expand...
Because it’s less expensive and more proven.
There are what maybe as high as a dozen +/- J20 built perhaps 2 dozen with prototypes. Each one far more complicated than a Flanker in computer systems and still more being built.
Taking one J20 and dropping new engines on it will slow production and reduces the numbers going to the squadrons.
Where as China has what 300 +/- Flanker variants on hand. It’s a simpler computer system and more easily integrated. Less worry about the engines effecting the RCS of the bird.
 
Blitzo

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
It's normal for a new engine before its first test flight to go through a whole heap of pre flight tests and verifications and that would be the same regardless of whether the first test aircraft was a J-20 or a Flanker.

The fact that they chose a Flanker rather than a J-20 first is obviously related to just the desire for risk reduction.
I'm sure they could have taken one of the J-20 201X prototypes and dropped WS-15 in it if they wanted to and there shouldn't be any effect on current production of J-20s. But again, risk reduction.



Point is, if we accept the rumour that WS-15 has been installed on a test aircraft (likely a Flanker), we don't know various key information:
- when was WS-15 installed
- what tests may have been done yet/what tests may be left before a first flight
- has a test flight occurred yet already


Without knowing all of that, we can only confidently say that WS-15 has been rumoured to have been installed on a Flanker, but we can't say either way if a test flight may have been conducted yet.
 
P

pipaster

Junior Member
Registered Member
TerraN_EmpirE said:
Because it’s less expensive and more proven.
There are what maybe as high as a dozen +/- J20 built perhaps 2 dozen with prototypes. Each one far more complicated than a Flanker in computer systems and still more being built.
Taking one J20 and dropping new engines on it will slow production and reduces the numbers going to the squadrons.
Where as China has what 300 +/- Flanker variants on hand. It’s a simpler computer system and more easily integrated. Less worry about the engines effecting the RCS of the bird.
Click to expand...


My question is why (more directed at this general conversation, not just you)?

What benefit is there to test an engine that will never be installed in a particular aircraft?

The risk reduction would be better done in a IL-76 type aircraft, with multiple other engines in case something unexpected occurs.

Most tests are best suited to ground facilities that can simulate many different conditions (where the program likely is right now). Aside from validating low oxygen / low pressure environments (already tested on the ground), what risk reduction will occur by placing an engine in a J-11 type aircraft?

The real testing will begin once confidence is gathered to test a J-20 with two WS-15s, and the associated control, taxi'ing, and flight tests that will ensue.

Right now we are waiting for this test, or the low possibility of seeing that IL-76 engine testbed aircraft with a new nacelle and hopeful big WS-15 on the side. But because AECC doesn't have to market their engines, and the PLA's better opsec practices, make this unlikely. I think we just have to wait an be surprised when a new nozzle starts appearing on a J-20.
 
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