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

747 Flight Deck escape reels.

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

747 Flight Deck escape reels.

Thread Tools
 
Search this Thread
 
Old 21st Sep 2008, 21:06
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2004
Location: England
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
747 Flight Deck escape reels.

Hi all

I have an extremely tecchy question, one which I have failed so far to get an answer to.

How long are the Inertia reels on the 747?

This is a two part Question:-
a) Length for a normal descent, i.e. out of the escape hatch and down the left side of the a/c.

b) Length for a right hand side descent i.e. out of the escape hatch over the dome and down the right hand side of the a/c.

This has been the subject of some serious debate, and would like to see if we can get some resolution on these questions.

Can anyone help?
Hubbly is offline  
Old 21st Sep 2008, 22:05
  #2 (permalink)  
 
Join Date: Jun 2005
Location: AEP
Age: 80
Posts: 1,420
Likes: 0
Received 0 Likes on 0 Posts
747 Escape Reels

For the 100/200 -
xxx
The escape reels are of sufficient length to be used through the escape hatch onto the LH side OR the RH side. There is very little difference in "length" passing the cable on either side. The hatch is offset (to the left) only by about 1 to 2 feet.
xxx
It is possible to use the same reels for exit through the RH upper deck door (and optional LH upper deck door) on the 100/200 type airplanes, or even through the spiral staircase (passenger 100/200 types) or ladder (cargo upper deck types) to be used for egress through L-1 OR R-1 doors.
xxx
In case of partial gear attitude (body gear NOT extended) it is possible that the length of the escape reel will not be sufficient to permit to reach the ground level, should the aircraft fall on the tail.
xxx
On the 300 series, escape reels are usable through the escape hatch only.

Happy contrails
BelArgUSA is offline  
Old 23rd Sep 2008, 08:59
  #3 (permalink)  
 
Join Date: Apr 2000
Location: UK
Posts: 56
Likes: 0
Received 0 Likes on 0 Posts
According to my manuals, on the 747-400 they are approximately 63ft (19.2m) long, and will allegedly reach the ground even if the aircraft tips on its tail. I assume this means down either side... Hope that helps.
Jumbo Jockey is offline  
Old 24th Sep 2008, 02:09
  #4 (permalink)  
 
Join Date: Jul 2000
Location: Smogsville
Posts: 1,424
Likes: 0
Received 0 Likes on 0 Posts
Don't use two reels thinking it will give redundancy, apparently it will double your descent speed!
SMOC is offline  
Old 4th Oct 2008, 21:42
  #5 (permalink)  
Thread Starter
 
Join Date: Oct 2004
Location: England
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
Thank you kindly for the information.

It has been invaluable.
Hubbly is offline  
Old 5th Oct 2008, 10:51
  #6 (permalink)  
 
Join Date: Jun 2005
Location: AEP
Age: 80
Posts: 1,420
Likes: 0
Received 0 Likes on 0 Posts
CG for occupants evacuation

Hubbly - Forgot to mention.
xxx
On the 747-200C and 200F, there was an AFT CG limit for full upper deck occupancy.
If CG was AFT of (cannot recall the %), upper deck limited to "X" number of occupants.
Cockpit crew + additional people - based on number of escape reels.
This in case the airplane (body gear) would not extend, and fell on its tail.
Was also based on inflatable slides from upper deck + 1 or 2 upper deck doors.
These scary things they would make you jump from, and brake your neck...!
I looked in my AOM, but most of my notes for freighters have been removed.
With Cargolux, the 747-271C upper deck had some 16 F seats for passengers
xxx

Happy contrails
BelArgUSA is offline  
Old 5th Oct 2008, 11:42
  #7 (permalink)  
 
Join Date: Mar 2006
Location: TLV
Age: 50
Posts: 113
Likes: 0
Received 0 Likes on 0 Posts
The CG limit is 26%.
In case the CG is behing 26%, plus no body-gear landing, the a/c might tip on it's tail so we are supposed to use L5 door with an escape rope fixed to it.
747dieseldude is offline  
Old 24th Jun 2011, 12:19
  #8 (permalink)  
 
Join Date: Mar 2007
Location: Europe
Posts: 163
Likes: 0
Received 0 Likes on 0 Posts
Please excuse me for the thread dig up.

Don't use two reels thinking it will give redundancy, apparently it will double your descent speed!
Could somebody elaborate a little bit?

I've heard that story as well, but don't really understand how the inertia reels work.
Does it mean a 50kg man will fall down twice as fast than a 100kg man?
fly123456 is offline  
Old 25th Jun 2011, 04:45
  #9 (permalink)  
 
Join Date: Feb 1998
Location: Formerly of Nam
Posts: 1,595
Likes: 0
Received 0 Likes on 0 Posts
Been a while since I've flown the Whale but I still recall that
lovable beast quite clearly -

Each reel provides the same ROD to the deck depending on one's
individual weight. So a 50kg nubile hostie should descend at the
same rate as the 110kg captain who was trying to chat her up.

If TWO reels were used by the same person, each reel would
perceive a lighter weight and allow an increase in inertial ROD.

This is why it was pointed out on Day One NEVER to grab a whole
fistful of reels, just because holding on to just one is outside one's
psychological comfort zone for a 40ft drop. Grab just one, hang on
and pray like hell it don't break!

18-Wheeler would be able to confirm this as I believe he's current
on type.
Slasher is offline  
Old 25th Jun 2011, 13:48
  #10 (permalink)  
 
Join Date: Sep 2010
Location: earth
Posts: 1,341
Likes: 0
Received 0 Likes on 0 Posts
Suppose some reel "play on words" expert advice could be given by the fight crew of hijacked PanAm flight 73. Got out before the terrorist's could reach the cockpit, rendering their plans useless.
grounded27 is offline  
Old 25th Jun 2011, 16:59
  #11 (permalink)  
 
Join Date: Apr 2009
Location: A place in the sun
Age: 82
Posts: 1,269
Received 50 Likes on 20 Posts
Slightly off the original question, but I tried the reel once on a 747-200 and it was a very comfortable controlled descent!
Bergerie1 is offline  
Old 25th Jun 2011, 22:29
  #12 (permalink)  
 
Join Date: Jul 2001
Location: Gold Coast
Age: 58
Posts: 1,611
Received 0 Likes on 0 Posts
Slasher - I agree with all that - but I haven't been on 747's since late 2007 unfortunately, so things may have changed in the mean time.
18-Wheeler 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.