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Is it a 'thing' that Airbus produce helicopter rotor systems that rotate differently?

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Is it a 'thing' that Airbus produce helicopter rotor systems that rotate differently?

Old 9th Nov 2020, 17:12
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Is it a 'thing' that Airbus produce helicopter rotor systems that rotate differently?

Do Airbus build different rotor systems dependent on customer? I.e Clockwise for France, Counter-clockwise for Germany? I heard this today, never heard it before...
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Old 9th Nov 2020, 17:18
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No...
use the pedals as required to maintain heading in the hover.
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Old 9th Nov 2020, 17:18
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Originally Posted by Hueymeister View Post
Do Airbus build different rotor systems dependent on customer? I.e Clockwise for France, Counter-clockwise for Germany? I heard this today, never heard it before...
No! But some types like H125, H225 ( the french ones ) turning clockwise, others like H135/H145 ( the german ones) turning the other direction.

skadi
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Old 9th Nov 2020, 17:23
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Originally Posted by Hueymeister View Post
Do Airbus build different rotor systems dependent on customer? I.e Clockwise for France, Counter-clockwise for Germany? I heard this today, never heard it before...
Well itís true that AH Germany aircraft rotate the opposite to AH France ones, but nothing to do with customers. Just heritage - AHD was originally MBB, and AHF was originally SA. Both chose different paths that have continued.

You donít honestly believe that they would design different versions of the same model for customers?
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Old 9th Nov 2020, 17:29
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Just wanted to fact check something I'd been told....one never knows these days!
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Old 9th Nov 2020, 17:49
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I thought it was because Coriolis forces provide an additional rotational component to clockwise rotating systems in the northern hemisphere and vice versa. That's why helicopters aren't allowed to cross the equator without some nautical engineering ceremony performed by drunken sailors...perhaps I'm getting confused.
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Old 9th Nov 2020, 17:50
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very drole mon brave
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Old 9th Nov 2020, 18:07
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nautical engineering ceremony performed by drunken sailors...perhaps I'm getting confused.
Absolutely true, have to fly northern hemisphere choppers in the southern hemisphere for half their life and vice versa otherwise the MRGB gets tangled up......so I woz told!

Frighteningly half those blokes were dressed as women and looked better than some of the Pompi lasses!
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Old 9th Nov 2020, 18:20
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The SA321 Super Frelon was the exception with a 6 bladed Sikorsky S61 derived Main Rotor system rotating counter-clockwise. Should have done the same thing for the S61, that would be a great lifter!
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Old 9th Nov 2020, 18:32
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Rotors turn a different way for the same reasons that propellers vary their rotation. It all depends where the drive is taken off the engine.

All engines rotate clockwise looking from the front. If one attaches the propeller on to the crankshaft at the front of the engine the propeller will rotate clockwise looking from the front. In the USA the propeller drive is normally taken off the back of the engine where a clutch would be in an automobile so they turn the engine around so the propeller is in front therefore the propeller goes anti clockwise looking from the front.

Helicopter drives to the gearboxes using a similar speed reduction system will cause the rotors to go different ways according to the design of the piston engine. With gas turbines you arrange it so that it goes the same way as before.

An example is the Super Frelon. French designed and built but the only one with an anti clockwise rotation because the rotor system was licence built from Sikorsky.
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Old 9th Nov 2020, 20:05
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Good theory, but unfortunately it’s not true that all aero engines rotate in the same direction.
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Old 9th Nov 2020, 20:44
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Just make sure the t/r blades are fitted correctly for the rotation.......
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Old 9th Nov 2020, 21:17
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Originally Posted by Fareastdriver View Post
Rotors turn a different way for the same reasons that propellers vary their rotation. It all depends where the drive is taken off the engine.

All engines rotate clockwise looking from the front. If one attaches the propeller on to the crankshaft at the front of the engine the propeller will rotate clockwise looking from the front. In the USA the propeller drive is normally taken off the back of the engine where a clutch would be in an automobile so they turn the engine around so the propeller is in front therefore the propeller goes anti clockwise looking from the front.

Helicopter drives to the gearboxes using a similar speed reduction system will cause the rotors to go different ways according to the design of the piston engine. With gas turbines you arrange it so that it goes the same way as before.

An example is the Super Frelon. French designed and built but the only one with an anti clockwise rotation because the rotor system was licence built from Sikorsky.
Absolute drivel
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Old 10th Nov 2020, 06:12
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It depends on which side of the road you drive on.
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Old 10th Nov 2020, 08:35
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Just make sure the t/r blades are fitted correctly for the rotation.......
Sycamore - did you witness the TH incident as well? Amazing that it took so long to realise it was a possibility!
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Old 10th Nov 2020, 08:39
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Originally Posted by Fareastdriver View Post
All engines rotate clockwise looking from the front.
Really? I seem to recall Stanley Hooker mentioning in his book that Merlin and Griffon crankshafts rotate in different directions. And I'm sure I've hand-swung direct-drive light-aircraft propellers in different directions in my time.
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Old 10th Nov 2020, 08:54
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I believe the P-38 Lightning had "handed" Allison engines, left hand engine crankshaft rotating clockwise, right hand anti-clockwise. Some Twin Comanches and Navajos had counter-rotating props which I think also used handed engines rather than gears to determine prop rotation.
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Old 10th Nov 2020, 12:20
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CJ, don`t know about TH,thinking about either a WX or S-K that had blades fitted incorrectly......
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Old 10th Nov 2020, 15:30
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I talked to a Sikorsky rep once about why they did not upgrade the S61 with more powerful engines, and composite rotor blades. He said that Sikorsky were quite willing to do it, but they wanted the operators to put up some money first.
No one would.
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Old 10th Nov 2020, 16:08
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Originally Posted by Dave B View Post
I talked to a Sikorsky rep once about why they did not upgrade the S61 with more powerful engines, and composite rotor blades. He said that Sikorsky were quite willing to do it, but they wanted the operators to put up some money first.
No one would.
That seems to be a common issue. Some operators with heavy maintenance expertise have had success improving upon the original design- and some like Erickson and Viking (Twotter) even buying the license. Seems like the Carson blades do the trick nicely. https://www.carsonhelicopters.com/s-61-crmb
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