Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

How Long???

Old 4th Jan 2019, 16:57
  #1 (permalink)  
Thread Starter
 
Join Date: Feb 2006
Location: Hanging off the end of a thread
Posts: 15,802
How Long???

Innovation In Tight Spaces

The current guidelines used for aircraft maintenance required that the entire engine be removed, which would require at least 36 hours per jet.
but does reveal the surprising fact that it takes “at least 36 hours” to remove an F-35A engine – and presumably another 36 hours to replace it.
It would take longer to fit BTW.

Coltrin went on to say that their partnership is strong because many of the functions that existed within a traditional maintenance squadron with fourth generation aircraft now lie within the fifth-generation aircraft maintenance squadron.

More now than ever we rely on each other to accomplish organic maintenance. On fifth-gen aircraft it takes a village. No squadron can go it alone,” said Coltrin.
organic maintenance.
How apt, no artificial fertiliser, just natural pure sh*te
LOL 36 Hours.



..

Last edited by NutLoose; 4th Jan 2019 at 17:09.
NutLoose is offline  
Old 4th Jan 2019, 18:02
  #2 (permalink)  
 
Join Date: Oct 2013
Location: Bristol
Age: 37
Posts: 304
I guess they aren't supposed to break...
unmanned_droid is offline  
Old 4th Jan 2019, 18:07
  #3 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 4,558
Is that supposed to mean 36 'man hours'. Should that be so its six blokes in six hours.
Fareastdriver is offline  
Old 4th Jan 2019, 19:02
  #4 (permalink)  
 
Join Date: Oct 2005
Location: Anglia
Posts: 1,868
Typical assumption of man-hours over elapsed time. Even with 6 people it is more reasonable to assume 10-15 hours elapsed time.
Rigga is offline  
Old 4th Jan 2019, 19:41
  #5 (permalink)  
Thread Starter
 
Join Date: Feb 2006
Location: Hanging off the end of a thread
Posts: 15,802
I don't think it is man hours because in the article it says

Maintainers working with field support engineers from Lockheed Martin and Pratt and Whitney set out to find a way to replace the fuel line without removing the engine.

Crew chiefs determined they could access the part through a hole just big enough to fit a hand. The location of the fuel line is nearly impossible to see. They needed to detach and set aside another component without removing it, making room even scarcer.
When the OTI was first accomplished, the fuel line swap took about 24 hours, 12 hours less than removing the entire engine and performing the maintenance on a stand. As they repeated the task on additional aircraft,


so if you only have a single hand access and that takes 24 hours, but 36 man hours works out less when you spread them across the team, then you would pull the engine as it's a quicker fix. I suppose the thing is the jumping bean version with the front lift fan etc.
NutLoose is offline  
Old 5th Jan 2019, 15:32
  #6 (permalink)  
 
Join Date: Oct 2005
Location: Closer than you think...
Age: 60
Posts: 384
Why not just make the access hole bigger, or are we then getting into material stress territory?
Always a Sapper is offline  
Old 5th Jan 2019, 16:28
  #7 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 70
Posts: 16,264
Recruit some skinny wimmen!

Problem sorted.
SASless is online now  
Old 5th Jan 2019, 16:58
  #8 (permalink)  
 
Join Date: Jul 2002
Location: Under a recently defunct flight path.
Age: 72
Posts: 1,011
Ah yes, man-hours. I recall the WO on Aircraft Repair Flt 390 MU many years ago stating to SEngO regarding a small repair estimated at forty man-hours, that if he had forty men he would have done in an hour...

And now back to your regular programme.
Lyneham Lad is online now  
Old 5th Jan 2019, 16:59
  #9 (permalink)  
 
Join Date: Apr 2009
Location: Hotel Gypsy
Posts: 2,830
Last VSTOL aircraft I saw on the RAF inventory could have the whole job done in a few hours, in a hide, in a boggy field, having removed the wings to get to it.
Cows getting bigger is offline  
Old 5th Jan 2019, 17:26
  #10 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 76
Posts: 16,570
It isn't the first aircraft with impractical access. Wasn't it a Victor or Herc where a fitter got his arm in but couldn't get it out? IIRC they had to open up the wing.
Pontius Navigator is online now  
Old 5th Jan 2019, 17:28
  #11 (permalink)  
 
Join Date: Jan 2014
Location: Norfolk
Posts: 344
Originally Posted by Always a Sapper View Post
Why not just make the access hole bigger, or are we then getting into material stress territory?
You will probably find that the access hole is actually there to service a different component but is being used (at a stretch) to get access to this particular fuel line. Panels tend to add weight and reduce strength so the designers have to strike a balance between the needs of the maintainers and the structural requirements of the airframe. Usually the maintainers lose out.
Vendee is offline  
Old 5th Jan 2019, 17:45
  #12 (permalink)  
 
Join Date: Oct 2013
Location: Bristol
Age: 37
Posts: 304
Originally Posted by Vendee View Post
You will probably find that the access hole is actually there to service a different component but is being used (at a stretch) to get access to this particular fuel line. Panels tend to add weight and reduce strength so the designers have to strike a balance between the needs of the maintainers and the structural requirements of the airframe. Usually the maintainers lose out.
Sorry - we will always push for fewer holes in our structures! Every one has a stress impact and thus a weight impact.
unmanned_droid is offline  
Old 5th Jan 2019, 18:14
  #13 (permalink)  
 
Join Date: Aug 2016
Location: Alberta
Posts: 26
Originally Posted by NutLoose View Post
Innovation In Tight Spaces





It would take longer to fit BTW.





How apt, no artificial fertiliser, just natural pure sh*te
LOL 36 Hours.



..

NutLoose
Given what I saw at the Smithsonian last summer I would say 36 hours to remove this engine is being generous.

BK

Last edited by Bksmithca; 5th Jan 2019 at 23:35.
Bksmithca is offline  
Old 5th Jan 2019, 20:15
  #14 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 4,558
Last VSTOL aircraft I saw on the RAF inventory could have the whole job done in a few hours, in a hide, in a boggy field, having removed the wings to get to it.
Did a field trial where we used a Puma to lift the wing off when it was in the middle of the sticks. A sod of a job putting it back on.
Fareastdriver 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


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.