Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Wrong residual crab on touchdown

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

Wrong residual crab on touchdown

Thread Tools
 
Search this Thread
 
Old 29th Jul 2011, 23:25
  #1 (permalink)  
Thread Starter
 
Join Date: May 2010
Location: Eyjafjallajokull
Age: 36
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Wrong residual crab on touchdown

I have this major problem after converting from narrow body to wide body aircraft: when there is some significant crosswind ( but not that strong ) I sometimes have this almost on touchdown despite making the decrab and straightening the nose. Somehow tha nose get pointing to downwid leading to a cruncher spoiling an otherwise good approach and flare. My skippers had helped me analysed those tendencies of the nose to go downwind; one surmised that I had relaxed on the upwind aileron prior to touchdown, one thought that I had too much rudder, one reckoned that " I has stopped flying the aircraft prior to touchdown letting the aircraft do it's own thing", etc. One was kinder, he reckoned that there might have been a wind shift just prior to touchdown!

I have never had this problem on the short narrow bodies but this is getting me all upset. Has anybody encounter such a problem? It's destroying my confidence in handling a big jet in variable wind conditions! Please help!
Kilda Ste Hilda is offline  
Old 30th Jul 2011, 00:37
  #2 (permalink)  
 
Join Date: May 2000
Location: Seattle
Posts: 3,196
Likes: 0
Received 0 Likes on 0 Posts
More rotational inertia is causing you to overcorrect? Try removing (by your eye) half of what you think you need...

As long as your velocity vector is straight down the runway, it doesn't much matter.
Intruder is offline  
Old 30th Jul 2011, 00:48
  #3 (permalink)  
 
Join Date: Jan 2007
Location: france
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Half decrab is better than over decrab, aim for half first, then as you get more confidence tend to fully decrab progressively. On a wet runway or with strong gusty crosswind half decrab is better anyway, and depending on the aircraft fast decrab can induce such an induced roll that full ailerons ain't enough to counter.
rollnloop is offline  
Old 30th Jul 2011, 06:28
  #4 (permalink)  
 
Join Date: Mar 2005
Location: Uh... Where was I?
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
I'd say that you have a wrong visual reference of the airplane longitudinal axis. Most likely due to the change of airplane.
Microburst2002 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.