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

Bone Question

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

Bone Question

Thread Tools
 
Search this Thread
 
Old 29th Jan 2010, 14:52
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2001
Location: wherever will have me
Posts: 748
Received 0 Likes on 0 Posts
Bone Question

Just a quick question - if a fixed wing has got 3 axes (lateral, normal and longtitudinal), what do you call them in a rotary wing, because haven't you got 4? Or am I being thick?

Cheers!
whowhenwhy is offline  
Old 29th Jan 2010, 15:23
  #2 (permalink)  
 
Join Date: May 2003
Location: OS SX2063
Age: 54
Posts: 1,028
Received 0 Likes on 0 Posts
We still have 3, we just find it easier to rotate about some of them and translate along all of them if we want.
VeeAny is offline  
Old 29th Jan 2010, 15:42
  #3 (permalink)  

Hovering AND talking
 
Join Date: Feb 2003
Location: Propping up bars in the Lands of D H Lawrence and Bishop Bonner
Age: 59
Posts: 5,705
Likes: 0
Received 0 Likes on 0 Posts
Fixed wing and helicopters also have a fourth dimension (as does everything); it's called time.

Cheers

Whirls
Whirlygig is offline  
Old 29th Jan 2010, 15:43
  #4 (permalink)  
Thread Starter
 
Join Date: Oct 2001
Location: wherever will have me
Posts: 748
Received 0 Likes on 0 Posts
So you can yaw around and move along the normal axis??
whowhenwhy is offline  
Old 29th Jan 2010, 16:35
  #5 (permalink)  
 
Join Date: May 2003
Location: OS SX2063
Age: 54
Posts: 1,028
Received 0 Likes on 0 Posts
WhoWhenWhy

Exactly That, the thrust generated by the tail rotor controls yaw (rotation) about that axis, and due to the fact that we can change the magnitude the thrust generated by the main rotor it gives us the ability to move up and down the normal axis.

Tail rotor thrust is controlled by the Yaw Pedals, Main rotor thrust magnitude is controlled by the collective pitch lever and the RPM of the main rotor which is sometimes manually controlled or sometimes mechanically or electrically governed. Although we usually operate most helicopters at constant RPM for the type.

Changing the alignment of that rotor thrust in space is what gives us control over where the aircraft goes.

As opposed to a traditional fixed wing which is usually pushed or pulled by something aligned roughly along the longitudinal axis and which needs to be moving itself to be able to rotate about any of the axes.

GS
VeeAny is offline  
Old 29th Jan 2010, 16:38
  #6 (permalink)  
Thread Starter
 
Join Date: Oct 2001
Location: wherever will have me
Posts: 748
Received 0 Likes on 0 Posts
VeeAny - many thanks. I should have just asked that question in the first place because that was the answer that I needed! Whirlygig, if you ever come up with a way of controlling the 4th dimension please let me know - I'd pay a lot!!!
whowhenwhy is offline  
Old 29th Jan 2010, 22:07
  #7 (permalink)  
 
Join Date: Jul 1999
Location: Warrington, UK
Posts: 3,842
Received 81 Likes on 33 Posts
I'd pay a lot!!
Yes me too! It's going far too quick these days.
MightyGem is offline  
Old 29th Jan 2010, 22:28
  #8 (permalink)  

Hovering AND talking
 
Join Date: Feb 2003
Location: Propping up bars in the Lands of D H Lawrence and Bishop Bonner
Age: 59
Posts: 5,705
Likes: 0
Received 0 Likes on 0 Posts
Mighty ... you need one of these ...



Never could get my head 'round tensor calculus

Cheers

Whirls
Whirlygig is offline  
Old 30th Jan 2010, 12:55
  #9 (permalink)  
 
Join Date: Feb 2005
Location: On the green bit near the blue wobbly stuff
Posts: 674
Likes: 0
Received 1 Like on 1 Post
Whirls,

With all that negative energy available behind the mouth - just wondering what the diagram of my Chief Instructor has to do with the space-time continuum?
Non-PC Plod is offline  
Old 30th Jan 2010, 13:53
  #10 (permalink)  
Below the Glidepath - not correcting
 
Join Date: Jun 2005
Location: U.S.A.
Posts: 1,875
Received 62 Likes on 19 Posts
Not forgettng that the Normal Axis is also called the Vertical Axis (eaiser to visualize). May be a Naval throwback, but equipment mounted aligned with the Lateral Axis is referred to as "Athwartships" - is that not a great word?
Two's in 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.