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

Rules Of thumb.

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

Rules Of thumb.

Thread Tools
 
Search this Thread
 
Old 8th Oct 2007, 13:10
  #1 (permalink)  
Thread Starter
 
Join Date: Jan 2006
Location: Australia
Posts: 179
Likes: 0
Received 0 Likes on 0 Posts
Rules Of thumb.

I am looking for rules of thumb that can assist me. Example a conversion to V/S for a gradient required when a speed is known. Rates of descent for a LLZ approach when the Glide Path is other than 3 degrees. There was a thread covering this sort of thing a while ago, but I cannot find it using the search facility.

Thanks.
novicef is offline  
Old 8th Oct 2007, 14:12
  #2 (permalink)  
 
Join Date: Jul 2007
Location: France
Posts: 610
Likes: 0
Received 0 Likes on 0 Posts
Novicef

A rule of thumb is 300 ft a nautical mile from the runway.(eg.900 ft. should be 3nm.)

On the Jeppesen approach plate it will show the rate of descent for various ground speeds in feet per minute.

For different glide slope angles, do an exercise & make your own table.
Tmbstory is offline  
Old 8th Oct 2007, 15:47
  #3 (permalink)  
 
Join Date: Apr 2002
Location: Bohol, Philippines
Posts: 150
Likes: 0
Received 0 Likes on 0 Posts
Gradient (%) x G/S (Kts) = V/S (ft/min)

E.g ILS (5%) x 140 kts = 700 ft/min
SFI145 is offline  
Old 8th Oct 2007, 16:05
  #4 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
novicef - look at the bottom of the screen
BOAC is offline  
Old 9th Oct 2007, 15:57
  #5 (permalink)  
 
Join Date: Oct 2006
Location: Hong Kong
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
google search "rules of thumb for pilots" and there it was......

http://www.flightinfo.com/rulesofthumb.htm
cxa340so is offline  
Old 9th Oct 2007, 20:40
  #6 (permalink)  
 
Join Date: Apr 2000
Location: 30 West
Age: 65
Posts: 926
Likes: 0
Received 0 Likes on 0 Posts
A fully loaded A330 will always go to 370 - trust me, I'm a docker
javelin is offline  
Old 10th Oct 2007, 05:36
  #7 (permalink)  
 
Join Date: Feb 1998
Location: Formerly of Nam
Posts: 1,595
Likes: 0
Received 0 Likes on 0 Posts
ROC fpm / GS kts = climb gradiant.
Examples
1000fpm / 150kts = 6.6% (mental 2:3 = 66:100 = 6.6%)
400fpm / 85kts = 4.7% (mental 1:2 = 50:100 = 5% minus a bit)
Slasher is offline  
Old 10th Oct 2007, 21:40
  #8 (permalink)  
 
Join Date: Jun 2000
Location: last time I looked I was still here.
Posts: 4,507
Likes: 0
Received 0 Likes on 0 Posts
3 degree glide path:

V/S = Gnd Spd divide by 0.2 + 50. e.g. 170/0.2 = 850 + 50 = 900. If the G.Spd is 175 round up or down to 170 or 180.

If slope is slightly steeper add 50 or 100fpm and see what happens. Reverse is true for shallower slope.

Nor sure what would happen on 6 degree slopes into special runways.

For those that say look at the Jeppe plate; I say on a dark night the text is too small to read. On modern EFIS a/c you have actual G.Spd readout, not an estimate from tower wind, so why not use it.
RAT 5 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.