COMAC C919

Rettam Stacf · Apr 22, 2022

Do not see how C919 can serve as a military transport.

Essentially all military transports, whether jet or turboprop powered, utilize high wing design for the fuselage to "hug" the ground for ease of roll in and roll out of military vehicles and other cargos. Also turboprop enables take off and landing on rough runways without worrying about sucking in debris like a jet engine would.

Blitzo · Apr 22, 2022

test1979 said:
Why not use the WS-20 instead? Similar thrust to cj-1000, and unified logistics with y-20?

I think it is worth clarifying what you mean here.

Do you mean a C919 for civilian markets using WS-20?

Or do you mean a militarized C919 for military purposes, using WS-20?

If you mean the former, then that is a no go, for various reasons that others have already listed.

If you mean the latter, then it is potentially more viable as a shorter term "domestic militarized" option. Such an aircraft would be powered by two WS-20s, and use domestic avionics systems/militarized as replacements for the current C919's major subsystems.
Such an aircraft could have many roles in the PLA, basically taking up the same roles that the current Y-8/9 special mission aircraft do and more:
- AEW&C
- MPA
- standoff EW/ECM
- ELINT, SIGINT
- Airborne command post
- Air to ground radar/ISR platform
... among others

BUT, a "domestic militarized" C919 might not be worth the time and money and aerospace resources of integrating WS-20 onto it, if the CJ-1000A is on the horizon.
If the CJ-1000A is on the horizon, we can bet that a domestic C919 for the civilian market would be on the horizon as well, and it would require time, money and aerospace resources to integrate CJ-1000A onto a domestic C919-civilian viable variant.
If that is the case, then pursuing a dual track "domestic C919" strategy may not be wise because you end up with two different major variants requiring their own separate logistics and suppliers for their engines and duplicating resource consumption during the engine integration for each aircraft.

A "domestic militarized" variant would be C919 with domestic subsystems and WS-20, and only be able to operate as a military airframe due to non-competitive engines for the civilian market.
A "domestic civil" variant would be C919 with domestic subsystems and CJ-1000A, and would be able to operate both as a military airframe as well as a civilian airliner for the civilian market.

Given that, I think the only reason for which a "domestic militarized" C919 variant would be deemed worthwhile, is if the CJ-1000A's maturity is very far into the future (say, well past 2030s), AND if the PLA desperately wanted a narrow body jet airliner airframe as the basis for special mission roles that I mentioned above.

But otherwise, I don't think a "domestic militarized" C919 is a good expenditure of resources, and that I think awaiting for the "domestic civil" C919 variant is better.

test1979 · Apr 22, 2022

Bltizo said:
I think it is worth clarifying what you mean here.

Do you mean a C919 for civilian markets using WS-20?

Or do you mean a militarized C919 for military purposes, using WS-20?

If you mean the former, then that is a no go, for various reasons that others have already listed.

If you mean the latter, then it is potentially more viable as a shorter term "domestic militarized" option. Such an aircraft would be powered by two WS-20s, and use domestic avionics systems/militarized as replacements for the current C919's major subsystems.
Such an aircraft could have many roles in the PLA, basically taking up the same roles that the current Y-8/9 special mission aircraft do and more:
- AEW&C
- MPA
- standoff EW/ECM
- ELINT, SIGINT
- Airborne command post
- Air to ground radar/ISR platform
... among others

BUT, a "domestic militarized" C919 might not be worth the time and money and aerospace resources of integrating WS-20 onto it, if the CJ-1000A is on the horizon.
If the CJ-1000A is on the horizon, we can bet that a domestic C919 for the civilian market would be on the horizon as well, and it would require time, money and aerospace resources to integrate CJ-1000A onto a domestic C919-civilian viable variant.
If that is the case, then pursuing a dual track "domestic C919" strategy may not be wise because you end up with two different major variants requiring their own separate logistics and suppliers for their engines and duplicating resource consumption during the engine integration for each aircraft.

A "domestic militarized" variant would be C919 with domestic subsystems and WS-20, and only be able to operate as a military airframe due to non-competitive engines for the civilian market.
A "domestic civil" variant would be C919 with domestic subsystems and CJ-1000A, and would be able to operate both as a military airframe as well as a civilian airliner for the civilian market.

Given that, I think the only reason for which a "domestic militarized" C919 variant would be deemed worthwhile, is if the CJ-1000A's maturity is very far into the future (say, well past 2030s), AND if the PLA desperately wanted a narrow body jet airliner airframe as the basis for special mission roles that I mentioned above.

But otherwise, I don't think a "domestic militarized" C919 is a good expenditure of resources, and that I think awaiting for the "domestic civil" C919 variant is better.

Even according to COMAC's schedule, the CJ1000A will not be put into use until at least 2027.
Keep in mind that the WS-20 is an engine designed to civilian standards, it is considered similar to the cfm-56, there are thousands of cfm-56s in service around the world and will continue to be used for many years to come.
The economy of the WS-20 is not as good as that of the CJ1000, but it is still affordable for most airlines.

test1979 · Apr 22, 2022

latenlazy said:
Airliners won’t fly their C919s if they’re not cost effective. If C919s can’t fly with an engine equivalent in economic performance to western options their sales will either be cancelled or they will be bought and then warehoused. There is no “good transition” for the commercial space. You either perform competitively against the rest of the market or you’re dead.

China has a huge domestic aviation market, enough to afford the economic burden.
Keep in mind that the WS-20 is an engine designed to civilian standards, it is considered similar to the cfm-56, there are currently over 600 airliners using the cfm-56 on domestic routes in China and will continue to be in use for at least many more years.
The WS-20 is not as economical as the CJ1000, but still affordable for most airlines.
ARJ-21 would not have been growing if only economic factors were taken into account.

Blitzo · Apr 22, 2022

test1979 said:
Even according to COMAC's schedule, the CJ1000A will not be put into use until at least 2027.
Keep in mind that the WS-20 is an engine designed to civilian standards, it is considered similar to the cfm-56, there are thousands of cfm-56s in service around the world and will continue to be used for many years to come.
The economy of the WS-20 is not as good as that of the CJ1000, but it is still affordable for most airlines.
View attachment 87559

So, you're saying that you want WS-20 to be used for a "domestic civil" C919?

Let's pretend that WS-20 is competitive with old CFM-56s for civilian specific parameters.

And let's take the 2027 date as when CJ-1000A is in service for C919.

Integrating WS-20 onto C919 will still take time and consume aerospace resources -- it would take at least 2-3 years. Structural redesign, integration, flight testing would all have to be done. This is on top of replacement of other domestic subsystems for C919 that would be occurring concurrently.

So, a WS-20 equipped C919 airframe likely would not be ready until 2024-2025. That's a difference of 2-3 years between a WS-20 equipped C919 and a CJ-1000A equipped C919.
Is that three year gap really that important to have a WS-20 equipped C919, considering it would almost immediately be replaced in production by the CJ-1000A equipped C919 afterwards, given CJ-1000A would be far superior to WS-20 for the civilian airliner flight profile?

Heck, even if WS-20 equipped C919s continue in service for a number of years, is it really worth supporting two domestic C919 variants in the world into the future, simply so China can have a "domestic C919" flying a few years earlier?

And remember, all of this is assuming that the WS-20 is sufficiently worthwhile for civilian airlines to operate and "affordable" for them to operate, which in reality may not be the case at all.

So no, I don't think integrating WS-20 onto C919 as a "domestic variant" for the civilian market is sensible. I believe it would be a waste of resources.
The only way in which a domestic variant of C919 using WS-20 would make sense, is if the PLA really wanted a domestic C919 variant for military purposes only, and were unwilling to wait for the domestic civil C919 variant powered by CJ-1000A.

tphuang · Apr 22, 2022

WS-20 is not designed to civilian standard. There is a huge gap in reliability, availability, maintainability and serviceability of WS-20 vs CJ-1000A. The requirement for fuel burn rate is a lot higher for CJ-1000A than WS-20.

Let's put it this way. If WS-20 equipped C919 is available 90% of time vs a Leap-1C equipped C919 being available 99.5% of time, then no airline would be picking WS-20 engine unless as a favor to the government.

Airlines have really low margin. A 5 to 10% difference in fuel burn and having to keep around 4 times the number of spare aircraft to operate a schedule reliably will bankrupt an airline.

Again, I would really caution putting a military engine on C919 when it will put undesirable attention on the C919 program. You don't want Western suppliers of C919 to drop out when C919 has yet to be certified anywhere.

ACuriousPLAFan · Apr 22, 2022

test1979 said:
Even according to COMAC's schedule, the CJ1000A will not be put into use until at least 2027.
Keep in mind that the WS-20 is an engine designed to civilian standards, it is considered similar to the cfm-56, there are thousands of cfm-56s in service around the world and will continue to be used for many years to come.
The economy of the WS-20 is not as good as that of the CJ1000, but it is still affordable for most airlines.
View attachment 87559

The development work for CJ-2000 at the bottom seems far from complete...

On another note, I am very eager to see planes adapted for transportation of Chinese government officials that are not made by Boeing or Airbus.

Imagine the PRC Air Force Ones that are COMAC C929s instead of the Boeing 747s. Also PRC Air Force Twos that is of the COMAC C919s instead of the Boeing 737s.

Apart from that, in case China gets cut off by the EU and the US like how Russia is going through right now - Technically speaking, Russia could offer IL-96s and Tu-214s. But it's not like they are reliable either, just take a look at the number of units that both Tupolev and Ilyushin can manufacture per year.

So it's always better for China to have their own reliable alternatives.

gelgoog · Apr 22, 2022

The Il-96 and Tu-214 are reliable. Just obsolete. One is basically an A340 and the other a 757. You could reduce the fuel consumption issue with a re-engine to a PD-14M engine. Which still does not exist. But you would still have the issue with outdated avionics. Some claim that avionics issue has been solved but I am less sure about it. The A340 and 757 are borderline usable in the current market. And are basically being phased out. Most companies already retired their A340s. You could argue that if Russian oil & oil products exports decrease and they won't have other replacement aircraft then the extra fuel consumption does not matter in their case. But in China's case, since they are not a major oil producer, the economics will be different. China needs efficient aircraft. And I think China is still like a decade until being able to built its own domestic civilian transport 100% in China in this segment. Russia is probably like two years away from mass production of the domestic MC-21.

TerraN_EmpirE · Apr 22, 2022

757 is still popular, even though Technologically “obsolete”. This is as Boeing when they designed it for it into a unique niche. It’s wide wing, over powered engines and size class. It’s a niche class that even today doesn’t have a equivalent. It won’t until the A321XLR delivers yet even then it’s still not quiet a match.

test1979 · Apr 22, 2022

Bltizo said:
So, you're saying that you want WS-20 to be used for a "domestic civil" C919?

Let's pretend that WS-20 is competitive with old CFM-56s for civilian specific parameters.

And let's take the 2027 date as when CJ-1000A is in service for C919.

Integrating WS-20 onto C919 will still take time and consume aerospace resources -- it would take at least 2-3 years. Structural redesign, integration, flight testing would all have to be done. This is on top of replacement of other domestic subsystems for C919 that would be occurring concurrently.

So, a WS-20 equipped C919 airframe likely would not be ready until 2024-2025. That's a difference of 2-3 years between a WS-20 equipped C919 and a CJ-1000A equipped C919.
Is that three year gap really that important to have a WS-20 equipped C919, considering it would almost immediately be replaced in production by the CJ-1000A equipped C919 afterwards, given CJ-1000A would be far superior to WS-20 for the civilian airliner flight profile?

Heck, even if WS-20 equipped C919s continue in service for a number of years, is it really worth supporting two domestic C919 variants in the world into the future, simply so China can have a "domestic C919" flying a few years earlier?

And remember, all of this is assuming that the WS-20 is sufficiently worthwhile for civilian airlines to operate and "affordable" for them to operate, which in reality may not be the case at all.

So no, I don't think integrating WS-20 onto C919 as a "domestic variant" for the civilian market is sensible. I believe it would be a waste of resources.
The only way in which a domestic variant of C919 using WS-20 would make sense, is if the PLA really wanted a domestic C919 variant for military purposes only, and were unwilling to wait for the domestic civil C919 variant powered by CJ-1000A.

In this respect, CJ1000 and WS-20 are the same, SF-A was initially considered as the engine of C919. If the WS-20 needs to restart testing on the C919 for 2.3 years, the same is true for the CJ1000 after the forensics are completed. It takes 2 or 3 years of testing to replace the c919 with the CJ1000. That means it won't be put into use until at least 2030. And this requires a major premise. CJ1000 must be completed strictly according to COMAC's schedule, but COMAC's record has been poor in this regard.

COMAC C919

Rettam Stacf

Junior Member

Blitzo

Lieutenant General

test1979

Junior Member

test1979

Junior Member

Blitzo

Lieutenant General

tphuang

Lieutenant General

ACuriousPLAFan

Brigadier

gelgoog

Lieutenant General

TerraN_EmpirE

Tyrant King

test1979

Junior Member