bongo
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B 777 Engines Vs. A 380 Engines

Fri Jun 17, 2005 7:04 am

Are they similar? Which engine is bigger ?

Thanks.
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jumbojim747
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RE: B 777 Engines Vs. A 380 Engines

Fri Jun 17, 2005 7:19 am

The 777 engines are bigger.
The A380 doesn't require the engine size of the T7 because it has 4 engines thus not requiring the thrust of the T7 engines
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prebennorholm
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RE: B 777 Engines Vs. A 380 Engines

Fri Jun 17, 2005 9:01 am

The 380 relies on new engine versions, RR Trent 900 and GP 7200, both rated at 70klbs, 77klbs for the somewhat heavier freighter version.

That's not enough for the 777 mainly since it has only one engine instead of three in case of engine failure during take-off.

The various versions of the 777 relies on engines from all three large engine manufacturers with some 85 to 115klbs thrust, the largest only from GE.

If the rumors about a future stretched 380 (380-900) show to be more than rumors, then we will see it with engines approaching the same max thrust as the low end of 777 versions.
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Starlionblue
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RE: B 777 Engines Vs. A 380 Engines

Fri Jun 17, 2005 11:44 am

The math is pretty simple. Assuming all (weight, wing and so on) is equal except the number of engines, a twin will need 50% more total thrust than a quad.

Say a quad needs 25k lb thrust per engine for a total of 100k lb. With one engine out it has 75k lb, which needs to be enough for climb (as per certification requirements).

The equivalent twin also needs 75k lb total thrust to climb (on one engine), giving it a total thrust of 150k lb.


Even though the 777 is a much lighter plane than the 380, it need much more thrust per pound of weight.

As Prebennorrholm says, the 388 engines are rated at 70-77k lb. The highest thrust 777 engines are for the 773ER and rated at 115k lb.
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