Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

Noise Footprint to height ?

Wikiposts
Search
Rotorheads A haven for helicopter professionals to discuss the things that affect them

Noise Footprint to height ?

Thread Tools
 
Search this Thread
 
Old 23rd Nov 2002, 19:32
  #1 (permalink)  

Senis Semper Fidelis
Thread Starter
 
Join Date: Feb 2001
Location: Lancashire U K
Posts: 1,288
Likes: 0
Received 0 Likes on 0 Posts
Noise Footprint to height ?

Picture this, very bright moonlight, nil wind, in fact a night as peaceful as John Prescotts concience, sounds of rotors approaching fast, powered by a turbine, the As350 of my local constabulary passes right over my house, and Bingo exactly 6 counted seconds the noise has gone, total footprint about 12 to 13 seconds, to those of you who know these things, would this point to a very fast and low alt journey, or a new sort of "Whisper mode" to sneak up on Billy Burglar, I must admit to being a little puzzelled?
Vfrpilotpb is offline  
Old 24th Nov 2002, 07:56
  #2 (permalink)  
 
Join Date: Aug 2000
Location: UK
Posts: 3,680
Likes: 0
Received 1 Like on 1 Post
Hi VFR, how's life?

Wouldn't be a 350, has to be a twin (355).

Min height at night over built up area: 500'.

Squirrels are noisy anyway.

Are you saying that it sounded low or noisy?
Thomas coupling is offline  
Old 24th Nov 2002, 12:52
  #3 (permalink)  
 
Join Date: Jun 2002
Location: Avon, CT, USA
Age: 68
Posts: 472
Likes: 0
Received 0 Likes on 0 Posts
Could it have been an EC-120 ? I believe one of those flew over my house last summer and once it passed over the noise quickly faded away.
ATPMBA is offline  
Old 24th Nov 2002, 21:57
  #4 (permalink)  

Senis Semper Fidelis
Thread Starter
 
Join Date: Feb 2001
Location: Lancashire U K
Posts: 1,288
Likes: 0
Received 0 Likes on 0 Posts
Hi T-C

I am pretty sure the ASU at Warton are still on the AS355 ( my slip saying AS350) I am trying to find out if there is any way that height can be correlated to the footprint, there is a guy at Clitheroe has a new 109, the CPL fly's it at about a fixed 2000ft and you can hear that machine for minutes before he passes over, but the one that got me thinking was the AS355 to which my first post referred, then again I suppose 500ft and a pretty fast flight may keep the footprint down quiet a lot, not looking to complain, just stretching my thoughts a little.

T-C I hope that you are well, and still chasing motor bikes
we had an AS350 with us two weeks ago, what an incredible machine, didn't know such things could be done with these birds!
Vfrpilotpb is offline  
Old 25th Nov 2002, 05:56
  #5 (permalink)  
 
Join Date: Nov 2000
Location: Pewsey, UK
Posts: 1,977
Received 18 Likes on 7 Posts
I hope I never get a commercial job to Clitheroe - I don't think I'd be able to find it.

Sorry, Vfr - couldn't resist !
The Nr Fairy is offline  
Old 25th Nov 2002, 20:51
  #6 (permalink)  
 
Join Date: Aug 2000
Location: UK
Posts: 3,680
Likes: 0
Received 1 Like on 1 Post
VFR: the guys at Warton have receipt of their all singing all dancing £2.8 million, EC135 IFR EFIS CPDS.....you won't hear it...it's got whisper mode, on

Only jealous.............take care.
Thomas coupling is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.