A300 captain reports low air flow from packs running off the APU during preflight. During climbout f...

Narrative:

During preflight I noticed and mentioned to the mechanic; how low the force of air coming from the packs was; while operating off the APU. He responded that the flight inbound was normal. The airflow continued to decrease during climbout until FL200 when both packs failed. Both packs were selected on due to the low flow that came out of the vents. When both packs failed I and the first officer got on the O2 and I declared the emergency with center and began the decent to 10;000 ft. We attempted to start the APU at the 10;000 ft level but it failed as well. I did open the ram air valve and we made the landing without any problem.

Original NASA ASRS Text

Title: A300 Captain reports low air flow from packs running off the APU during preflight. During climbout flow continued to decrease with altitude until packs failed at FL200. An emergency was declared and flight returned uneventfully to the departure airport.

Narrative: During preflight I noticed and mentioned to the Mechanic; how low the force of air coming from the packs was; while operating off the APU. He responded that the flight inbound was normal. The airflow continued to decrease during climbout until FL200 when both packs failed. Both Packs were selected on due to the low flow that came out of the vents. When both Packs failed I and the First Officer got on the O2 and I declared the emergency with Center and began the decent to 10;000 FT. We attempted to start the APU at the 10;000 FT level but it failed as well. I did open the Ram Air valve and we made the landing without any problem.

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.

Attributes
ACN	855502
Time
Date	200910
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Other On SID/STAR
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Pilot Not Flying Captain
Events
Anomaly	Aircraft Equipment Problem Critical

A300 captain reports low air flow from packs running off the APU during preflight. During climbout flow continued to decrease with altitude until packs failed at FL200. An emergency was declared and flight returned uneventfully to the departure airport.