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-   -   Rotation of RR, GE & PW (https://www.pprune.org/tech-log/537410-rotation-rr-ge-pw.html)

wcy 5th Apr 2014 11:54

Rotation of RR, GE & PW
 
Hi mates, i am trying to understand the differences among RR, GE & PW engines.
When i am standing in front of the engine, if the fan moves in anti-clockwise direction, it is a RR engine. Otherwise it is a GE / PW engine.
do i understand correctly?
thanks.:ok:

awblain 5th Apr 2014 15:46

Isn't it:
clockwise looking at the spinner - RR;
anti-clockwise - everyone else?

underfire 5th Apr 2014 15:48

Most Pratts and GE rotate counter clockwise, if looking at them. Most Rolls Royce jet engines, on the other hand, rotate backwards.

oceancrosser 5th Apr 2014 20:30

And why would the direction of roation make a difference to anyone? :ugh:

As long a all engines of same type rotate in the same direction...

Ozlander1 5th Apr 2014 21:27


Originally Posted by underfire (Post 8420267)
Most Pratts and GE rotate counter clockwise, if looking at them. Most Rolls Royce jet engines, on the other hand, rotate backwards.


Maybe that's why they drive on the wrong side of the road. :cool:

DevX 5th Apr 2014 21:57

"Most Rolls Royce jet engines, on the other hand, rotate backwards.
"

Seeing as we Brits actually invented the jet engine I would suggest that it is in fact American engines that rotate 'backwards'. :ok:

JammedStab 6th Apr 2014 02:38

I believe that the Germans were first. Like in so much else. Earlier flight.

And even the French beat the Brits as well(not like in so much else) as the first patent for using a gas turbine to power an aircraft was filed in 1921 by Frenchman Maxime Guillaume.

Maxime Guillaume, "Propulseur par réaction sur l'air," French patent no. 534,801 (filed: 3 May 1921; issued: 13 January 1922). Available on-line (in French) at: http://v3.espacenet.com/origdoc?DB=E...0&QPN=FR534801

DevX 6th Apr 2014 04:44

It's one thing filing a patent, quite another to get a successful working model which would eventually revolutionise the future of air travel.

Anyway, if you really want to split hairs check out Aegidius Elling.

grounded27 6th Apr 2014 04:59


And why would the direction of roation make a difference to anyone? :ugh:

As long a all engines of same type rotate in the same direction...
I would feel more comfortable with RR powered aircraft in the southern hemisphere.. LOL

DevX 6th Apr 2014 05:21

Quote:
Maybe that's why they drive on the wrong side of the road.

Archaeological evidence proves that even in the Roman days carts were driven on the left due to the obvious practicalities. Even in the earlier days of American history the left side was considered the norm, but of course like everything else adopted over there, the English language included, it was changed for seemingly no good reason. :ugh:

gas path 7th Apr 2014 21:33

Of course just to complicate matters, with the latest incarnations of their motors both GE and RR the high pressure spool rotates backwards compared to the fan.:}

underfire 7th Apr 2014 22:41

Archaeologcal evidence also shows we used stone knives and wore animal skins.
Evolution has not been the same on the disconnected continents.

Isnt Britain still ruled by a Queen or King? :}

tdracer 7th Apr 2014 23:23


but of course like everything else adopted over there, the English language included, it was changed for seemingly no good reason.
Many years ago, while in the UK on business, I was watching some talk show on TV. IIRC, Clive James was leading the discussion - anyway they were lamenting how much less "colorful" the English version of the English language was compared to the American version.

misd-agin 8th Apr 2014 00:54

RR were originally engineered to rotate the same direction as PW and GE engines. Unfortunately a significant part of the engineering was done in South Africa and Australia. When they took the engineering drawings north of the equator they weren't corrected for northern hemisphere production. Ergo RR jets rotate 'backwards'.

TWT 8th Apr 2014 01:59

Yes,the southern hemisphere designers were influenced by the Coriolis Force !

Water Down a Plughole › News in Science (ABC Science)

Canuckbirdstrike 8th Apr 2014 11:03

Not all GE engines rotate the same way...... The GE-NX rotates the same way as RR engines.

sooty655 8th Apr 2014 18:40

And just to confuse the issue further, the Bristol (later RR) Pegasus rotated both ways at the same time.

barit1 8th Apr 2014 18:47

The T64 (& CT64) held the longest-duration-production record for a GE jetmoteur - roughly 1958 to late 1990's. And it rotates backwards i.e. clockwise viewed from the front.

That production record has been recently broken by the TF39/CF6 family, 1966-present; CF6's are still produced for the C-5M re-engining project. CF6's turn the right direction. :}

DevX 8th Apr 2014 19:35

Canuckbirdstrike Quote: Not all GE engines rotate the same way...... The GE-NX rotates the same way as RR engines.

See, you're eventually coming around to doing things the correct way! :D

Oh, and Clive James? What does he know about the English language anyway, he's an Aussie! :}

Turbine D 8th Apr 2014 20:58

The reason the GEnx fan rotates the same direction as RR engines is that it, along with the LP turbine, was designed to rotate in the opposite direction of the compressor, that's all.

Maybe the rotation direction of RR engines goes back to the days of the prop for the Sopwith Camel which had the great ability to turn right, but not so much so turning left.:ok::)


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