Chinese Engine Development
- Thread starter jackbh
- Start date
Again (am I repeating myself?)
J-20 project is at least 10 years old. Even if you must argue it is 5 years old, WS-10A was not in production in 2005. Even if you say it was 3 years old, WS-10A was not used in any fighters in PLAAF 3 in 2007. Not for quality issue, but for slow "spool-up" time. (It takes twice as long to spin up as AL-31F).
Regarding J-15, there is NO POINT in spending the time and money on one with WS-10A because anyone with any little bit of clue would know WS-10A cannot be used for J-15 production for years. You want them to do it just for fun?
The only way that your argument makes any sense is if you believe it takes five months to design J-20.
Who knows, maybe you are right. Maybe the Chinese designers are so incredible. Maybe you are an aircraft designer that you know how to design a 4G fighter in months.
No, those two don't follow, and I'm not sure why you're not getting this. Not knowing if something's reliable doesn't mean that it's unreliable. It's very possible that the WS-10 hasn't been installed in enough numbers for a long enough period of time for the PLA to know its availability before constructing the J-20 prototype.
There are quite a number of questionable assertions here, but I don't have the time right now to explain things. Suffice it to say, too many POVs with too little (or even biased) sources running around to make these sorts of firm conclusions.
Well, let's use an analogy. If you're running a company and you hired a new guy fresh out of college, would you trust his reliability? No. Because there's nothing to confirm that he is. However, just because nothing confirms that he's reliable doesn't mean that he's unreliable either, or else every single fresh graduate would be labeled unreliable by this standard. The solution to this problem would be to treat everyone as unreliable, especially when the project is important, until he proves his reliability.
You have no background in engineering and manufacturing, do you?
1. Certification happens when the engine satisfies the design requirement. That does not mean the engine was ready for production.
2. Certification doesn't even mean the engine is ready for integration. That requires additional design and testing. In this case, problems were found that about spool-up time.
3. Only once all the bugs were figured out, the engine goes into manufacturing.
4. An engine which performs well during the design stage does not mean it can be easily manufactured. WS-9 (which Chinese bought the right) took YEARS before it can be manufactured reliably. It was so bad that China had to buy refurbished Spray for JH-7. So it is bound that problems will be found during the initial years of manufacturing. That's why the initial production rate is low.
Finally, have you ever lived (and driven a car) close to the beach? Or lived (and driven a car) in a city which snow a lot during the winter and use salt to clean the roads? The erosion is incredible. It takes years from the usable life of the car.
And operating land-based aircraft is not the same from operating on a carrier. Nobody builds airport next to the water. However, on the carrier, you will get mist of salt water.
AL-31F doing fine on the carrier does not mean WS-10A will do fine. Remember the Russian standard on maintenance is only few hundred hours. The requirement for WS-10A was much higher.
Finally, since you are such a big fan for CAC (I am a fan for CAC too but I am much more realistic). Have you see the cockpit photo of J-10? It is ancient comparing to JF-17. JF-17 was flying six years ago. Why couldn't CAC come up with J-10B in 2006 with the updated cockpit? Well, that's the life in aircraft development. I am sure J-10B program started ground 2006, and it took them five year to get to first flight.
So, assuming WS-10A fixed the spool-up problem in 2008/2009 timeframe, we will not see it used in any new projects (other than J-11B, which has been testing WS-10A since ~05/06) until 2015.
What are you credentials with regard to engineering? Have you been involved with military jet engine development before?
That is what I have been saying, but you previously denied that the WS-10 has quality issues. You said that the reason it was held up was due to spool-up times. I am saying that quality control has been the bigger problem.
I still don't buy it, an aircraft engine is going to corrode or not corrode, just because it is Russian doesn't automatically make it resistant to sea salt. Your argument makes no sense. What you are saying is that SAC engineers decided not to test the J-15 with the engine that it would use in production because it would corrode the engines. So instead, they decided to go with the AL-31F...and engine which...is also unprotected and not designed to handle sea salt. The AL-31F is just a regular engine, it has no special modification that make it corrosion resistant. But I'll even give it to you.
It makes no difference anyway. The J-15 is, and will be for the next few years, tested on LAND. There is no reason to use AL-31s.
I am well aware that these things take a long time to develop, perhaps better than you. You said the J-10B project began in 2006 and it took five years for the first flight. The J-10B flew in 2009, check it. That is three years...not five.
I am being very realistic. I am not some huge CAC fanboy either, I am just looking at the facts.
You keep telling me that I am wrong but you are not inadequately explaining why the PLAAF is so hesitant to use WS-10s.
The J-11BS prototypes used WS-10, but the J-15s prototypes have not. Why? The J-11BS flew years before the latter, the engine was more mature by the time the J-15 came around.
The J-15 prototypes aren't seeing any water or any corrosion. They could be fitted with WS-10s just as the J-11BS was years EARLIER. Why are they not? You still haven't explained this. Huitong suggests that a J-11BS crashed, maybe the crash caused SAC to rethink putting an immature engine on future prototypes (hence the J-15 and J-20 were stuck with AL-31Fs). SAC is going to use WS-10 engines on the prototypes if they can because ultimately the J-15 is going to be powered by them. It doesn't make sense to test and aircraft with a different engine, and then go back and repeat some of the testing again with the final engine. The fact that SAC did not use WS-10 on the J-15 is telling.
The J-20 is in not threat of corrosion either. The J-11BS flew with WS-10s 3-4 years before the J-20. My argument still applies as it does with the J-15. There is a reason that these engines are not being used.
That reason is not supply. They will make sure there are enough engines for testing aircraft, aside from the fact that AL-31Fs are not being ordered or produced anymore, and therefore are in shorter supply.
It is not spool-up times because the J-20 and J-15s don't require faster spool up times for now. Besides, they wouldn't be using the WS-10 engines on J-11B or J-11BS if their performance was all that bad. If it can power a combat ready J-11B it can power a J-15 or a J-20 prototype.
It is not corrosion resistance.
It can only be concerns with quality. That's it.
It depends on how the Chinese would use the engines.
For example:
Boeing's 787 is planned to be reliable in 2014.....for common passengers like you and me...
But it will not be considered as a reliable plane for important passengers like Obama and Arabian kings by then.
A prototype is more important than a mass produced plane just as a president is more important than a common passenger. If the prototype crashes, the whole project will be delayed for several months to several years. Some Chinese fanboys said SAC once used newly-developed WP-14 on their J-8C prototype in 1990s. After the protoptype crashed due to the engine failure, the project was delayed and cancelled at last.
AL-31 was used on prototypes of J-15 and J-20 because it had been in service for over 20 years so it was considered as a more reliable engine than Taihang, which was reportedly in service in 2007(?).
In engineering, reliability is given by the form of decimal fraction, like 0.9 or 0.999, so there isn't a reliable engine or an unreliable engine but a more reliable engine and a less reliable engine. A F110-GE-100 may be more reliable than an AL-31F, and AL-31F is more reliable than WS-10, so the Chinese would use F110 to power their prototype J-15 for it was more reliable if they could get some. But they will use Taihang to power the mass produced planes just because America is less reliable.
