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Y-20 heavy transport aircraft News & Discussions

vi-va

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Question for aviation experts - why can't these same engines be used for civilian aircrafts? I understand design is different, but is it more economical to design a totally new engine for civilian aircrafts?
The civil one and military one can be the same one, with some minor changes for sure, as long as the requirements specs are the same.

The military one safety standard usually can be a bit lower, versus civilian safety standard is quite high.

If Y-20 engine has 99.9% reliability, which means one of the four engines of Y-20 may stop working in 1,000 taking off and landing. It's totally acceptable.

C-919 engine may need 99.999%+ reliability. Do the math, if you are operating 1000 c-919 daily in China, and each of them make 2 taking off and landing per day. In one year, you have 700,000 landing and taking off.

99.999% reliability means 7 times of engine stop working per year. C-919 has only 2 engines, one engine stop working can be handled by design, but still dangerous. 7 times of engine stop working per year means the civilian jet failed in the market. No one dare to take it.
 

Beast

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The civil one and military one can be the same one, with some minor changes for sure, as long as the requirements specs are the same.

The military one safety standard usually can be a bit lower, versus civilian safety standard is quite high.

If Y-20 engine has 99.9% reliability, which means one of the four engines of Y-20 may stop working in 1,000 taking off and landing. It's totally acceptable.

C-919 engine may need 99.999%+ reliability. Do the math, if you are operating 1000 c-919 daily in China, and each of them make 2 taking off and landing per day. In one year, you have 700,000 landing and taking off.

99.999% reliability means 7 times of engine stop working per year. C-919 has only 2 engines, one engine stop working can be handled by design, but still dangerous. 7 times of engine stop working per year means the civilian jet failed in the market. No one dare to take it.
Not necessary military one has lower spec than civilian. The CFM-56 used on C-17 need to withstand sandstorm or highly dusty environment due to need to land on unpave runaway. While civilian do not as they always land on well maintain international runaway.

Of cos, civilian CFM-56 used on Airbus or Boeing need to emit less noise compare to one used on C-17.
 

Deino

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Not necessary military one has lower spec than civilian. The CFM-56 used on C-17 need to withstand sandstorm or highly dusty environment due to need to land on unpave runaway. While civilian do not as they always land on well maintain international runaway.

Of cos, civilian CFM-56 used on Airbus or Boeing need to emit less noise compare to one used on C-17.

Minor nit-pick correction: The C-17 does not use CFM-56 but Pratt & Whitney F117-PW-100 turbofan engines, which are a military variant of the PW2000 but otherwise I agree with you.
 

vi-va

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Not necessary military one has lower spec than civilian. The CFM-56 used on C-17 need to withstand sandstorm or highly dusty environment due to need to land on unpave runaway. While civilian do not as they always land on well maintain international runaway.

Of cos, civilian CFM-56 used on Airbus or Boeing need to emit less noise compare to one used on C-17.
@Deino
My original post is civilian engine safety standard is higher, my point still stands.

Yes, military one has some special requirement, as you pointed out. But do you know C-17 taking off and landing in high dust environment will damage the engine very badly? It will need special maintenance, replace parts, clean the dust, and so on.

Taking off and landing in a high dust environment is not a standard C-17 tactic, it's allowed with preconditions A, B, C and so on. The cost is quite high.
 

serenity

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What is important or different about this version ?
It is a refueling plane.

Y-20 will have three main types, transport, refueling, and AWACS. Maybe also include electronic warfare and command aircraft too in future due to importance of controlling Dark Sword UCAV not just by J-20B and J-16 fighters.

WS-20 engines would give it even more available power for those electronic attack roles or allow a more powerful radar similar in size to KJ-2000 but just more modern.
 

Shotgunner51

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It is a refueling plane.

Y-20 will have three main types, transport, refueling, and AWACS. Maybe also include electronic warfare and command aircraft too in future due to importance of controlling Dark Sword UCAV not just by J-20B and J-16 fighters.

WS-20 engines would give it even more available power for those electronic attack roles or allow a more powerful radar similar in size to KJ-2000 but just more modern.
Yes Y-20 will serve as platform for tanker and AWACS, though I hope a civilian-platform covert like C919/929 can join the service in the long run. WS-20 engines should be ready soon, recall this exiting video earlier this year:

 
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FuturePAF

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Dont know why pak not buying these jets
These are backbone of any airforce
Higher operating costs then turboprop transports, but probably also waiting for the design to be mature enough (probably around making sure the engines are reliable enough) to avoid dealing with teething pains the PLAAF maybe experiencing with the type.
 

Beast

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Higher operating costs then turboprop transports, but probably also waiting for the design to be mature enough (probably around making sure the engines are reliable enough) to avoid dealing with teething pains the PLAAF maybe experiencing with the type.
I dont think this kind of huge transport plane shall not buy blindly. As what you mention, they have high operating cost due to 4 turbofan. They are only needed when need to transport overweight stuff like MBT.

Of cos the advantage of turbofan will be payload and flying speed.
 

Deino

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They are because china using 3D modeling system to manufacre them quikly if paf order we can buy them if lethal chinese j 31 is available dont think that would be an issue

Come on ... the reason since China is using 3D modeling is proof that the Y-20 is for sale? I must admit I find all your latest posts to put it mildly at best weird and strange, to say it clear, completely off and proof that you havE NO understanding of what you say!
 

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