J-20... The New Generation Fighter III

latenlazy said:

Doesn't really address the point...

Click to expand...

I told you about article regarding materials used in T-50 and reasons they decided that materials they gonna use for tactical LO fighter put reasonable speed limits for Mach 2.35
You beginning to tell me of various composites in existence (thank you, Captain) that can withstand much higher speeds. Should we reach reinforced carbon-carbon for hypersonic fighter or stop somewhere at current AS4-BMIs floor? Or J-20 uses something more advanced that F-22 and T-50 'to boldly go to Mach 3' (I say, with these 'perfectly' suited for that DSI inlets)?

Come on this discussion is useless ! The AL-31FN was the best China and CAC could acquire at a time when the own WP-15 failed again. As such it’s even more ridiculous to discuss how many “possible” or actual crashes have occurred and even more without any information on whether they were engine-related or caused by other reasons. Even more since we don’t know how much this number would have been if powered by the WS-10A/B/C … or so.
IT’s like arguing whether the F-35 would be “better” with the F136 or the F-22 with the F120.

flateric said:

P.S. I do not bother was first reported crash is myth or not as engine not mentioned.

Click to expand...

As far as I know (from Bai Wei's report on the J-10 published in the AFM):



Cheers, Deino

flateric said:

How long ago 'one' became 'numerous' in your world and how this make you convinced that it makes your statement right? 'Numerous crashes caused by engine failure' you said. Proof? List?
Regarding 'success stories' - any proof of 'numerous', again?
Proceed...

Click to expand...

There are obviously more than one crash involving engine failure. Some claim that Al-31FN is more reliable, yet I have shown experience with J-10 shows this claim to be shaky. Has there been crash involving J-10 and Al-31FN? Yes. How? The engine has lubricant issues causing the gearbox to cease up leading to engine failures. Why would it be the engine and not improper maintenance? Because the identical problem occurs repeatedly, pointing to design as being the issue. Lubricant issues with Al-31FN are well known, and extra maintenance focuses on the gearbox which reduces accident rate rather than increases it. Al-31FN had its own reliability issues, which are not going to be disappeared by demanding me to provide service and maintenance records.

"Success stories" include , . occurred before July of 2005. Another crash occurred in that same year but not listed in Wikipedia.

I understand that you are from Russia, so you may have a lot of faith in Russian systems. However, you shouldn't let your emotion clouds your judgement. You are taking the position that Al-31 is more reliable and demand statistics to show otherwise, yet at the same time have no statistic backing up your position. You also don't have statistics to counter the statistics that I have already provided. If you frequent Chinese forums as often as some of us do, you would have known about Al-31FN's lubricant issues instead of demanding proofs from me.

flateric said:

P.S. I do not bother was first reported crash is myth or not as engine not mentioned.

Click to expand...

Whether you care about it or not, this is actually quite important as it shows there is no precedent of other causes that result in loss of a J-10.

flateric said:

I told you about article regarding materials used in T-50 and reasons they decided that materials they gonna use for tactical LO fighter put reasonable speed limits for Mach 2.35
You beginning to tell me of various composites in existence (thank you, Captain) that can withstand much higher speeds. Should we reach reinforced carbon-carbon for hypersonic fighter or stop somewhere at current AS4-BMIs floor? Or J-20 uses something more advanced that F-22 and T-50 'to boldly go to Mach 3' (I say, with these 'perfectly' suited for that DSI inlets)?

Click to expand...

I'm simply saying that I'd be suspicious if they claimed composites in general had that speed limit, since they're so varried and we're improving composites all the time (certain ceramic based composites for example have higher heat resistance). Not making any claims of mach 3 J-20s *rollseyes*

Engineer said:

There are obviously more than one crash involving engine failure. Some claim that Al-31FN is more reliable, yet I have shown experience with J-10 shows this claim to be shaky. Has there been crash involving J-10 and Al-31FN? Yes. How? The engine has lubricant issues causing the gearbox to cease up leading to engine failures. Why would it be the engine and not improper maintenance? Because the identical problem occurs repeatedly, pointing to design as being the issue.

Click to expand...

I've asked you questions about crash statistics because of engine failure caused by implemented design flaws and again receiving half a page of blah-blah. I've no emotions - show me statistics. Flight hours. Failure rate. Then we can compare it to other engines. 'Obviously more crashes' is not a figure, but your statement not supported by anything.

flateric said:

I've asked you questions about crash statistics because of engine failure caused by implemented design flaws and again receiving half a page of blah-blah. I've no emotions - show me statistics. Flight hours. Failure rate. Then we can compare it to other engines.

Click to expand...

Has J-10 crashed because of problems with Al-31FN? Yes. Has there been instance where J-10 loss power in mid-flight? Yes, multiple times, due to lubricant issues. Al-31FN isn't so reliable as some has claimed. Case closed.

If you have any statistics showing that Al-31FN is more reliable despite being the root cause of numerous crashes and crash landings, by all means show it. So far, you have done nothing of the sort, and have only been beating around the bush to avoid having to address the point.

flateric said:

'Obviously more crashes' is not a figure, but your statement not supported by anything.

Click to expand...

Nice strawman, but I did not say "obviously more crashes". I said "obviously more than one crash" in response to your flawed claim that there has only be one crash in your post.

Still no statistics for 'numerous crashes and crash landings' compared to total flight hours? No figures except "obviously more than one crash"?

My statistics is number of AL-31s bought and currently ordered by China.

Good bye.

flateric said:

Still no statistics for 'numerous crashes and crash landings' compared to total flight hours? No figures except "obviously more than one crash"?

My statistics is number of AL-31s bought and currently ordered by China.

Good bye.

Click to expand...

Still no numerical figure from you to support the original assumption that Al-31 is more reliable. Nor is there any figure from you showing that Al-31 is more reliable despite being the causes of numerous crashes and near-crashes.

As for the number of new Al-31FN brought by China, this has been addressed before: J-10A is designed to use Al-31FN, so obviously newly built J-10As will have to use Russian engines. China has to put up with it, or has no replacement for outdated J-7s. This however, does not prove Al-31FN being more reliable as some has claimed.

J-10A
number built ~190

maiden flight - spring 1998
IOC - end of 2003
crash due to AL-31FN malfunction - summer 2009

now go on and compare to F-16 A-class incidents due to F100/F110 problems

flateric said:

crash due to AL-31FN malfunction - summer 2009

Click to expand...

Crashes due to Al-31FN malfunction: , 2007(?), and . Close calls due to engine failures include one in , , and .