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

777, C1/C2 Hyd pumps.

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

777, C1/C2 Hyd pumps.

Thread Tools
 
Search this Thread
 
Old 29th Jan 2010, 08:22
  #1 (permalink)  
Thread Starter
 
Join Date: Sep 2005
Location: Colorado USA
Posts: 31
Likes: 0
Received 0 Likes on 0 Posts
777, C1/C2 Hyd pumps.

Guys,

During acceptance in Seattle we had to check the output for C1/C2 ELEC pumps. The manual says 2900 to 3200 PSI.
But I've checked the maintenance manual and it shows 2800 to 3200 PSI.
Did someone challenged our friends at KBFI already about this?
Thanks
bauduin_alex is offline  
Old 29th Jan 2010, 12:31
  #2 (permalink)  
 
Join Date: Oct 1998
Location: CGK to HKG
Posts: 249
Likes: 0
Received 0 Likes on 0 Posts
Pump pressure

I am assuming that the first manual is the Boeing Aircraft Acceptance Manual and would have harder values for you the customer.

The Maintenance Manual values would be the extreme limits, so when 2800psi is OK but one psi below and your pump is now requiring replacement. Not so good if you just had the aircraft delivered.
I would have thought that the upper value was too high to accept as well.

Might be totally wrong but going to double check with our B777 acceptance and AMM.

TW
Tinwacker is offline  
Old 29th Jan 2010, 13:41
  #3 (permalink)  
 
Join Date: Mar 2005
Location: England
Posts: 730
Likes: 0
Received 0 Likes on 0 Posts
I think Tinwacker has the answer, our AMM still states the following

SUBTASK 29-11-02-210-003
(7) Make sure the HYDRAULIC SYSTEM PRESS C indication, on the EICAS maintenance page, is
2800 to 3200 psi.
However for the Engine driven pump it states

SUBTASK 29-11-05-210-005-002
(4) Make sure the L (R) HYDRAULIC SYSTEM PRESS indication on the EICAS maintenance display
is 2900 to 3200 psi.
Perhaps this is where the confusion comes from also?
Fargoo is offline  
Old 7th Feb 2010, 14:08
  #4 (permalink)  
Thread Starter
 
Join Date: Sep 2005
Location: Colorado USA
Posts: 31
Likes: 0
Received 0 Likes on 0 Posts
Your right about the AMM content and that's what I ve found too. After discussion with one expert we came to the conclusion that the value into the acceptance manual is higher because brand new pump / system is supposed to produce at least the 2900. Maintenance will call for replacement/check if pressure goes below 2800. Hence the difference in both documents.
bauduin_alex 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.