A B737-300 departed after contract maintenance incorrectly wired an air conditioner ram air door in ...

Attributes
ACN	745722
Time
Date	200707
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 2000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 40 flight time total : 10000 flight time type : 3000
ASRS Report	745722
Events
Anomaly	aircraft equipment problem : critical maintenance problem : non compliance with mel maintenance problem : improper maintenance non adherence : published procedure non adherence : company policies
Independent Detector	other flight crewa
Resolutory Action	flight crew : diverted to another airport flight crew : landed as precaution
Consequence	other
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

Aircraft legally dispatched with right pack deferred inoperative. Aircraft had maintenance done on it in ZZZ by contract mechanic from local FBO to lock open the ram air door on the remaining good pack; as the door was malfunctioning on the previous flight and properly reported. On climb out of ZZZ the remaining pack tripped. The aircraft immediately started to depressurize. The checklist was run and the pack was unable to be reset by the checklist. We were now unpressurized with no air flow whatsoever. We advised departure of our need to divert and land due to a pressurization problem. Next; we contacted dispatch by voice and ACARS and it was agreed that we would divert to ZZZ1. Maintenance was consulted and agreed that an overweight landing would be acceptable at our weight. Departure facilitated us into a downwind for runway at ZZZ1. After advising crew and passenger of our situation; we made a normal overweight unpressurized landing at ZZZ1. Maintenance at ZZZ1 determined that the deflector door had been wired (by the contract mechanic in ZZZ) in the ground or deflected position -- not the open or flight position -- which caused the pack to overheat and fail. Passenger deplaned and a new aircraft was found for the flight to ZZZ3.

Original NASA ASRS Text

Title: A B737-300 DEPARTED AFTER CONTRACT MAINT INCORRECTLY WIRED AN AIR CONDITIONER RAM AIR DOOR IN THE CLOSED POSITION. FLT DIVERTED UNPRESSURIZED.

Narrative: ACFT LEGALLY DISPATCHED WITH R PACK DEFERRED INOP. ACFT HAD MAINT DONE ON IT IN ZZZ BY CONTRACT MECH FROM LCL FBO TO LOCK OPEN THE RAM AIR DOOR ON THE REMAINING GOOD PACK; AS THE DOOR WAS MALFUNCTIONING ON THE PREVIOUS FLT AND PROPERLY RPTED. ON CLBOUT OF ZZZ THE REMAINING PACK TRIPPED. THE ACFT IMMEDIATELY STARTED TO DEPRESSURIZE. THE CHKLIST WAS RUN AND THE PACK WAS UNABLE TO BE RESET BY THE CHKLIST. WE WERE NOW UNPRESSURIZED WITH NO AIR FLOW WHATSOEVER. WE ADVISED DEP OF OUR NEED TO DIVERT AND LAND DUE TO A PRESSURIZATION PROB. NEXT; WE CONTACTED DISPATCH BY VOICE AND ACARS AND IT WAS AGREED THAT WE WOULD DIVERT TO ZZZ1. MAINT WAS CONSULTED AND AGREED THAT AN OVERWT LNDG WOULD BE ACCEPTABLE AT OUR WT. DEP FACILITATED US INTO A DOWNWIND FOR RWY AT ZZZ1. AFTER ADVISING CREW AND PAX OF OUR SITUATION; WE MADE A NORMAL OVERWT UNPRESSURIZED LNDG AT ZZZ1. MAINT AT ZZZ1 DETERMINED THAT THE DEFLECTOR DOOR HAD BEEN WIRED (BY THE CONTRACT MECH IN ZZZ) IN THE GND OR DEFLECTED POS -- NOT THE OPEN OR FLT POS -- WHICH CAUSED THE PACK TO OVERHEAT AND FAIL. PAX DEPLANED AND A NEW ACFT WAS FOUND FOR THE FLT TO ZZZ3.

Data retrieved from NASA's ASRS site as of January 2009 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 B737-300 departed after contract maintenance incorrectly wired an air conditioner ram air door in the closed position. Flight diverted unpressurized.