A learjet 31 pressurization duct connection failed while climbing through FL360 because the glue con...

Narrative:

I was flying as first officer on a learjet 31. We departed for a 1.5 hour flight. This was to be the airplane's first flight following a twelve year inspection. The airplane was test flown by a factory learjet test pilot previously and declared airworthy; and returned to the maintenance facility. As we climbed through FL360 on our way to FL430; we experienced an abrupt loss of cabin pressure. It sounded as though the aft pressure bulkhead gave way and the cabin vsi immediately pegged at over 6;000 FPM cabin altitude. I informed ATC of the situation and told them we needed an immediate descend. We then donned 02 masks and initiated emergency descend procedures in accordance to the learjet aircraft flight manual. My priority at that time was to get the airplane as quickly and safely as possible to a safe altitude. As we passed through about 25;000 ft I noticed the emergency pressurization system seemed to have stabilized the cabin climb and I switched back to my regular headset as I was having trouble with my microphone in the O2 mask. I contacted ATC and was given instructions to continue my descent to 12;000 ft. I was asked if I needed to declare an emergency; and I told the controller the situation seemed to be under control at that point and requested to return to the departure airport. We landed with no further incident and left the airplane at the overhaul facility for repairs.

Original NASA ASRS Text

Title: A Learjet 31 pressurization duct connection failed while climbing through FL360 because the glue connecting a pressurization duct had not completely cured following an extensive maintenance overhaul.

Narrative: I was flying as First Officer on a Learjet 31. We departed for a 1.5 hour flight. This was to be the airplane's first flight following a twelve year inspection. The airplane was test flown by a factory Learjet test pilot previously and declared airworthy; and returned to the maintenance facility. As we climbed through FL360 on our way to FL430; we experienced an abrupt loss of cabin pressure. It sounded as though the Aft Pressure Bulkhead gave way and the cabin VSI immediately pegged at over 6;000 FPM cabin altitude. I informed ATC of the situation and told them we needed an immediate descend. We then donned 02 masks and initiated emergency descend procedures in accordance to the Learjet Aircraft Flight Manual. My priority at that time was to get the airplane as quickly and safely as possible to a safe altitude. As we passed through about 25;000 FT I noticed the emergency pressurization system seemed to have stabilized the cabin climb and I switched back to my regular headset as I was having trouble with my microphone in the O2 mask. I contacted ATC and was given instructions to continue my descent to 12;000 FT. I was asked if I needed to declare an emergency; and I told the Controller the situation seemed to be under control at that point and requested to return to the departure airport. We landed with no further incident and left the airplane at the overhaul facility for repairs.

Data retrieved from NASA's ASRS site as of July 2013 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	1050162
Time
Date	201211
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	Learjet 31
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning Distribution Ducting Clamps Connectors
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Commercial
Experience	Flight Crew Last 90 Days 12 Flight Crew Total 2585 Flight Crew Type 1658
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Maintenance

A learjet 31 pressurization duct connection failed while climbing through FL360 because the glue connecting a pressurization duct had not completely cured following an extensive maintenance overhaul.