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

Effect of wet runway on ASDR

Wikiposts
Search

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

Effect of wet runway on ASDR

Thread Tools
 
Search this Thread
 
Old 21st August 2012 | 12:28
  #1 (permalink)  
Thread Starter
 
Joined: Nov 2005
Posts: 18
Likes: 2
From: Uk
Effect of wet runway on ASDR

I have searched for this but have yet to get my head around the situation.

Compared to a dry ASDR the wet ASDR will be affected by reduced braking action requiring an increase in ASDR. However 2 factors that counteract this are that a wet V1 is typically used so the aircraft has less speed and energy to dissipate. Also, on a wet runway reverse thrust is permitted to be considered for stopping so would total braking action not be better on a wet runway than dry with wheel brakes only?

So does a wet runway make ASDR increase or decrease?
Paragon is offline  
Reply
Old 21st August 2012 | 15:21
  #2 (permalink)  
100 Countries Visited
25 Anniversary
 
Joined: Sep 1999
Posts: 5,552
Likes: 25
From: ME
Actually it can make it DECREASE thanks to the use of reverse thrust and lower screen height! THis is one of the reasons that software has a parameter restricting Wet takeoff weights "equal to" or "less than" dry takeoff weights.

Mutt
mutt is offline  
Reply
Old 21st August 2012 | 17:35
  #3 (permalink)  
1jz
 
Joined: Jul 2012
Posts: 121
Likes: 0
From: Tarmac
I don't see no relation of a screen height n asdr except when u compare it with a todr or a tor, but your wet asdr = greater of the dry both engine, 1 engine or a wet asdr calculation.
1jz is offline  
Reply
Old 21st August 2012 | 21:22
  #4 (permalink)  
20 Anniversary
 
Joined: May 2003
Posts: 412
Likes: 0
Paragon,

screen height is 15 ft for a wet runway, instead of 35 feet for dry. Mutt has it right. Note that he says "can", and not "will".
hawk37 is offline  
Reply
Old 22nd August 2012 | 17:58
  #5 (permalink)  
 
Joined: Apr 2008
Posts: 147
Likes: 0
From: Somewhere
Screen height isn't relevant for ASDR, as you're not getting airborne.
mini-jumbo is offline  
Reply

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 © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.