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A B727-200 in cruise at FL330 declared an emergency and diverted due to loss of cabin pressure caused by a defective right pack control switch.
| Attributes | |
| ACN | 412608 |
| Time | |
| Date | 199808 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : dfw |
| State Reference | TX |
| Altitude | msl bound lower : 33000 msl bound upper : 33000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zfw tower : iad |
| Operator | common carrier : air carrier |
| Make Model Name | B727-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other other other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | oversight : pic |
| Qualification | pilot : atp pilot : commercial pilot : flight engineer |
| Experience | flight time last 90 days : 200 flight time total : 7000 flight time type : 1500 |
| ASRS Report | 412608 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : flight engineer pilot : atp |
| Experience | flight time last 90 days : 190 flight time total : 6000 flight time type : 3000 |
| ASRS Report | 413238 |
| Events | |
| Anomaly | aircraft equipment problem : critical |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : declared emergency other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
Narrative:
60 mi west of dfw at FL330 cruising from slc to msy, experienced a depressurization to 12000 ft cabin altitude. Was able to coordinate through ATC for a descent to FL240. In descent, cabin pressure control regained. Landed in dfw because oxygen masks hanging in cabin upset some passenger. Landing and approach uneventful. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a B727- 200 and the pressure loss was caused by a 'soft' right pack switch. The reporter said the switch toggle could be moved to the center between on and off and had no detent in the on or off position. The reporter stated the so moved his hand up to adjust the position of the right ram air cooling door and lightly brushed against the pack switch with his sleeve inadvertently shutting off the right pack. The reporter said the aircraft cabin immediately began to climb. The reporter stated the switch was replaced at dfw.
Original NASA ASRS Text
Title: A B727-200 IN CRUISE AT FL330 DECLARED AN EMER AND DIVERTED DUE TO LOSS OF CABIN PRESSURE CAUSED BY A DEFECTIVE R PACK CTL SWITCH.
Narrative: 60 MI W OF DFW AT FL330 CRUISING FROM SLC TO MSY, EXPERIENCED A DEPRESSURIZATION TO 12000 FT CABIN ALT. WAS ABLE TO COORDINATE THROUGH ATC FOR A DSCNT TO FL240. IN DSCNT, CABIN PRESSURE CTL REGAINED. LANDED IN DFW BECAUSE OXYGEN MASKS HANGING IN CABIN UPSET SOME PAX. LNDG AND APCH UNEVENTFUL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A B727- 200 AND THE PRESSURE LOSS WAS CAUSED BY A 'SOFT' R PACK SWITCH. THE RPTR SAID THE SWITCH TOGGLE COULD BE MOVED TO THE CTR BTWN ON AND OFF AND HAD NO DETENT IN THE ON OR OFF POS. THE RPTR STATED THE SO MOVED HIS HAND UP TO ADJUST THE POS OF THE R RAM AIR COOLING DOOR AND LIGHTLY BRUSHED AGAINST THE PACK SWITCH WITH HIS SLEEVE INADVERTENTLY SHUTTING OFF THE R PACK. THE RPTR SAID THE ACFT CABIN IMMEDIATELY BEGAN TO CLB. THE RPTR STATED THE SWITCH WAS REPLACED AT DFW.
Data retrieved from NASA's ASRS site as of July 2007 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.