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Old 27th March 2017 | 23:17
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From: Truro
Merlin Noise

Hi All,

The Merlin HM/HC 1,2 and 3 makes a distinctive 'swishing' noise - why? Been asked a number of times by students and still don't have a convincing answer.

Thanks!

BN
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Old 28th March 2017 | 01:23
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From: In the gutter..........
Maybe it's the rustling of brown envelopes?
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Old 28th March 2017 | 05:34
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From: OAKN
It's a result of the blade tie down slots; AW installed cheap slots on the underside of the blade which act as a flute in the rotating air - hence the whistle. Other manufacturers use a bayonet fitting with a spring plunger which essentially seals the hole when not in use.
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Old 28th March 2017 | 06:24
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From: Truro
Thanks for replies - i had always thought it was blade-tether points but surely that would make a 5R swish as opposed to the distinctive 1R swish?
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Old 28th March 2017 | 06:58
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From: UK
They can only afford one tie-down rope.
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Old 28th March 2017 | 09:19
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From: EGDC
That's why the RAF gave them to the Navy - they always have odd bits of rope hanging around, they just call them funny names
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Old 28th March 2017 | 12:00
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From: England & Scotland
The whistle is a safety feature. If you don't hear it on start-up, you left the blades tied-down 🤕
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Old 29th March 2017 | 11:21
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From: Inverness-shire, Ross-shire
Some say it's the sound made by the accountant trying to justify the third engine.
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Old 29th March 2017 | 12:01
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From: Southwater
Merlin, Merlin?


https://www.youtube.com/watch?v=P2nlGN6aS8g


Last edited by Senior Pilot; 30th March 2017 at 06:25. Reason: YouTube insert
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