View Full Version : Merlin Noise
Bluenag
27th Mar 2017, 23:17
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
pants on fire...
28th Mar 2017, 01:23
Maybe it's the rustling of brown envelopes? :eek:
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.
Bluenag
28th Mar 2017, 06:24
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?
Fareastdriver
28th Mar 2017, 06:58
They can only afford one tie-down rope.
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;)
John R81
28th Mar 2017, 12:00
The whistle is a safety feature. If you don't hear it on start-up, you left the blades tied-down 🤕
jimf671
29th Mar 2017, 11:21
Some say it's the sound made by the accountant trying to justify the third engine.
RedhillPhil
29th Mar 2017, 12:01
Merlin, Merlin?
https://www.youtube.com/watch?v=P2nlGN6aS8g
P2nlGN6aS8g