China's transport, tanker & heavy lift aircraft


Deino

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Since the WS-20 is a generation older, itself based on the WS-10's core, which again was developed based on CFM-56 technology. As such it is more or less a full circle to a CFM-56-level engine but not a LEAPX one and thsi one is required for the C919 to archieve its economic performance.

Therefore, Yes, ... as a military engine for the Y-20 and eventually PLA variants, but not in commercial use.
 

t2contra

Major
Since the WS-20 is a generation older, itself based on the WS-10's core, which again was developed based on CFM-56 technology. As such it is more or less a full circle to a CFM-56-level engine but not a LEAPX one and thsi one is required for the C919 to archieve its economic performance.

Therefore, Yes, ... as a military engine for the Y-20 and eventually PLA variants, but not in commercial use.

I think it can work as an interim engine to the CJ-1000, in case the US embargoes the LEAPX. Could @crash8pilot give your opinion?
 

Deino

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I think it can work as an interim engine to the CJ-1000, in case the US embargoes the LEAPX. Could @crash8pilot give your opinion?


But for which airline? Do you think any Chinese airline would buy an uneconomic aircraft if they can get more economical ones in the West? ... but this is no longer a PLAAF large aircraft and transport issue.
 

siegecrossbow

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But for which airline? Do you think any Chinese airline would buy an uneconomic aircraft if they can get more economical ones in the West? ... but this is no longer a PLAAF large aircraft and transport issue.

If the Chinese military still offered cheap civilian transport like they did before the early 2000s then maybe there is a chance... But that is a story for another day.
 

Richard Santos

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Since the WS-20 is a generation older, itself based on the WS-10's core, which again was developed based on CFM-56 technology. As such it is more or less a full circle to a CFM-56-level engine but not a LEAPX one and thsi one is required for the C919 to archieve its economic performance.

Therefore, Yes, ... as a military engine for the Y-20 and eventually PLA variants, but not in commercial use.
There seems to me to be a couple of questions that needs to be answered to affirm the validity of this reasoning.
1. It is not entirely clear to me what exactly “based on” means. Was the hot section of the WS-10/20 a close copy of that of the CFM-56, or was it a mostly independent design but required a careful study of how the CFM design solved certain technical problems common to both designs to overcome some of its own major design hurdles? If it is the later, then depending on what the nature of the problems are that required CFM inspired solutions, the potential of WS-10/20 in terms of hot section efficiency may or may not be tightly constrained to that of the CFM.
2. If WS-10/20 hot section is a close copy of those in the CFM-56, so it’s potential is truly constrained to be similar to those of the CFM-56, it is still all together clear if the room for significant incremental improvement is truly exhausted. In the long run, CFM-56 potentials are clearly much more limited than a clean slate design begun 40 years later. If a company has solved the problems of a new generation engine, then from commercial perspective, even if there is still unexhausted potential for incremental improvement in the CFM56 design, it may be more strategic to invest instead in the new engine and leave CFM56’s potential unexplored. But for a player that still has someways to go to field a new engine, it may be commercially desirable to explore untapped potential still remaining in the CFM56. It is not clear either exactly how much untapped potential remainings in the CFM56, nor if at a cost, it can come close to matching key performance criteria of early iterations of a clean slate new design design for certain application.
3. If China sees any advantage to fielding domestic commercial aircraft using domestic engines early for its domestic market, where foreign aircraft as well as engine competitors can be excluded or handicapped.
 

crash8pilot

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I think it can work as an interim engine to the CJ-1000, in case the US embargoes the LEAPX. Could @crash8pilot give your opinion?
All this is a bit off topic thread, but I'm more than happy to continue the discussion in the appropriate thread.

But with that said between the pandemic, issues with the MAX, and delays to the 777x program, GE is burning through gobs of cash. They are in desperate need of cash flow to recover from one of the most disastrous periods in history, and that money won't be sufficient from local and European demand (case and point the airline I worked for has been in talks with Boeing and GE to delay their 777 and Dreamliner orders). Despite how many MAXs United pledges to buy, its pennies compared to the commercial airline market in China. The lobbying arm of GE cannot afford to allow the federal government to place further trade embargoes on Chinese business, and similarly the US Commerce Department cannot afford to let one of it's leading engineering companies suffer much longer and risk going under.

Based on operational manuals from my Airbus differences course (so that I could fly the A320ceo and neo), the fuel burn difference according between the IAE engine (the airline I worked for didn't use CFMs) and the LEAP is absolutely massive. We'd burn like 2.2 tons per hour on the IAE, but the manuals say that number goes down to ~1.8t at 30000ft. Two of my best friends work for another airline recently had a go at the MAX, and they told me they were burning ~1.6t at 40000ft with the LEAP. While I won't say the IAE/CFM engines are uneconomic or unprofitable, the margins and operational savings between engine generations is just mind blowing-ly massive - you won't lose tons of money operating an engine from the CFM56 generation, you're saving a helluva lot more from the LEAP.

I'm sure if push comes to shove in the trade war that a more commercially friendly variant of the WS-20 can be spun off as a stop gap for the CJ-1000 and provide comparable performance to the CFM56.... but realistically I just can't see how the Biden Administration can afford the risk of killing off a company that's crucial to national security despite how sour Sino-American relations are currently. All signs point to the CJ-1000 becoming a reality, GE and the US best milk the cow while they still can... especially when there aren't a whole lot of alternate sources of funding/income.
 
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Deino

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There seems to me to be a couple of questions that needs to be answered to affirm the validity of this reasoning.
1. It is not entirely clear to me what exactly “based on” means. Was the hot section of the WS-10/20 a close copy of that of the CFM-56, or was it a mostly independent design but required a careful study of how the CFM design solved certain technical problems common to both designs to overcome some of its own major design hurdles? If it is the later, then depending on what the nature of the problems are that required CFM inspired solutions, the potential of WS-10/20 in terms of hot section efficiency may or may not be tightly constrained to that of the CFM.
2. If WS-10/20 hot section is a close copy of those in the CFM-56, so it’s potential is truly constrained to be similar to those of the CFM-56, it is still all together clear if the room for significant incremental improvement is truly exhausted. In the long run, CFM-56 potentials are clearly much more limited than a clean slate design begun 40 years later. If a company has solved the problems of a generation engine, then from commercial perspective, even if there is still unexhausted potential for incremental improvement in the CFM56 design, it may be more strategic to invest instead in the new engine. But for a player that still has someways to go to field a new engine, it may be commercially desirable to explore untapped potential still remaining in the CFM56. It is not clear either exactly how much untapped potential is there in the CFM56, whether at a cost, it can come close to matching the performance of early iterations of a clean slate design.


I think those questions raised can only be answered by AVIC engineers and I think they won't tell you. Anyway, as far as the WS-10/20's core is a close copy or a development inspired/based on cannot be answered by anyone he I fear.
 

sndef888

Junior Member
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I think it is quite pointless to discuss using WS-20s on C919.

The possibility is just way too low.

The US would have to issue a long term ban of engines to China (destroying Boeing in the meantime), successfully convince all their allies to do the same, somehow convince Russia not to sell PS-90/PD-14s to China, and Cj-1000 project fails.

The sequence of events that would have to happen is way too much
 

avatar1234

New Member
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At this point there are well over 20 Y20 in service, no? Perhaps even reaching 30?
And the tanker variant is being delivered to active service but in low single digit numbers?
Is that the current situation?
Also, are there any detailed images of the tanker variant that would show if the plane has retained the cargo doors or if it was fully optimized to serve as a tanker?
 

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