A B747-400 captain reported loss of #2 air conditioning pack on an aircraft that had a history of pr...

Attributes
ACN	852433
Time
Date	200909
Local Time Of Day	1801-2400
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Pilot Not Flying Check Pilot Captain
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 17000 Flight Crew Type 1000
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Fuel Issue

Narrative:

Aircraft had history of pack #2 trips. Maintenance had checked pack #2 and cleared the inbound log write-up on the #2 pack. Pack #2 failed enroute and crew carefully followed the irr procedure. They were not able to recover the pack operation. As the flight progressed they had a steady loss of fuel. Ultimately they lost just over 5;000 pounds and arrived with 16.7 versus the 23.0 they were planned to arrive with. Suspect that the pack doors for the failed pack may have driven open as a result of the failure. That combined with the remaining two packs in hi flow and those packs probably operating harder requiring their doors to be open further may explain the increased burn. Would like to know if this speculation is correct. If so is there a way to force the cooling doors to close on a failed pack while enroute?

Original NASA ASRS Text

Title: A B747-400 Captain reported loss of #2 Air Conditioning Pack on an aircraft that had a history of problems with this pack. The issue was complicated with a high fuel burn; presumably due to the pack doors being driven open.

Narrative: Aircraft had history of Pack #2 trips. Maintenance had checked Pack #2 and cleared the inbound log write-up on the #2 Pack. Pack #2 failed enroute and crew carefully followed the IRR procedure. They were not able to recover the Pack operation. As the flight progressed they had a steady loss of fuel. Ultimately they lost just over 5;000 LBS and arrived with 16.7 versus the 23.0 they were planned to arrive with. Suspect that the pack doors for the failed pack may have driven open as a result of the failure. That combined with the remaining two Packs in Hi Flow and those Packs probably operating harder requiring their doors to be open further may explain the increased burn. Would like to know if this speculation is correct. If so is there a way to force the cooling doors to close on a failed Pack while enroute?

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A B747-400 captain reported loss of #2 air conditioning pack on an aircraft that had a history of problems with this pack. The issue was complicated with a high fuel burn; presumably due to the pack doors being driven open.