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Merlin Noise

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Merlin Noise

Old 27th Mar 2017, 23:17
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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 Mar 2017, 01:23
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Maybe it's the rustling of brown envelopes?
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Old 28th Mar 2017, 05:34
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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 Mar 2017, 06:24
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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 Mar 2017, 06:58
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They can only afford one tie-down rope.
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Old 28th Mar 2017, 09:19
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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 Mar 2017, 12:00
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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 Mar 2017, 11:21
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Some say it's the sound made by the accountant trying to justify the third engine.
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Old 29th Mar 2017, 12:01
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Merlin, Merlin?


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


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