# Incident 19960512044299I: Boeing 727290, Indianapolis, IN, May 12, 1996

- Type: FAA incident report (Accident/Incident Data System), as reported
- Date: May 12, 1996, 20:35 local time
- Place: Indianapolis, IN
- Airport: Indianapolis International
- Damage: No damage
- Phase of flight: Normal Cruise
- Operating rules: Air carrier (Part 121)
- Operator: AMTA
- Location: 39.7300° N, 86.2906° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=39.7300&lon=-86.2906&mi=10
- Aircraft: N775AT, a cancelled registration (https://openairdocs.org/deregistered/N775AT-2007-04-24) (OpenAirDocs)
- Registry model: Boeing 727-290 (registry code 138408W, https://openairdocs.org/model/boeing-727-290) (OpenAirDocs)
- Registry engine: Pratt & Whitney JT8D-1 (registry code 52044, https://openairdocs.org/engine/pratt-whitney-jt8d-1) (OpenAirDocs)
- Reported make and model: BOEING 727290
- Reported engine: PWA JT8D17
- People aboard: 105
- Fatal injuries: 0
- Pilot flight hours: 10,200 total, 3,000 in this make and model, 152 in the last 90 days
- NTSB investigation: [NTSB CHI96IA157](https://openairdocs.org/ntsb/CHI96IA157) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19960512044299I

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

NARRATIVE: ON 05-12-96, WHILE ENROUTE AT 33,000 FEET FROM CHICAGO, IL (MDW) TO ST. PETERSBURG, FL (PIE), AMERICAN TRANS AIR FLIGHT #406, A BOEING 727-290, N775AT, EXPERIENCED A LOSS OF PRESSURIZATION. AN EMERGENCY DESCENT WAS EXECUTED. THE AIRCRAFT DIVERTED TO, AND LANDED AT INDIANAPOLIS, IN (IND). PRIOR TO THE LOSS OF PRESSURIZATION, THE AIRCRAFT'S CABIN ALTITUDE WARNING HORN SOUNDED. THE RISE IN CABIN ALTITUDE WHICH CAUSED THIS WARNING HORN TO SOUND OCCURRED BECAUSE THE FLIGHT ENGINEER FAILED TO NOTICE THAT THE RIGHT PACK SWITCH WAS IN THE OFF POSITION. THE CAPTAIN OBSERVED THAT THE RIGHT PACK SWITCH WAS OFF. HE DIRECTED THE FLIGHT ENGINEER TO PLACE THAT SWITCH IN THE ON POSITION. AFTER DOING SO, THE FLIGHT ENGINEER ATTEMPTED TO REGAIN CONTROL OF THE CABIN'S PRESSURE. IN THIS ATTEMPT, HE FAILED TO CLOSE THE CARGO HEAT OUTFLOW VALVE. IN ADDITION, HE SELECTED MAN(UAL) AC ON THE ELECTRONIC PRESSURIZATION CONTROLLER AND TOGGLED THE PRESSURIZATION OUTFLOW VALVE TO THE OPEN POSITION. THIS CAUSED A RAPID LOSS OF CABIN PRESSURE WHICH NECESSITATED THE EMERGENCY DESCENT. IMMEDIATELY AFTER THE LOSS OF CABIN PRESSURE, BOTH THE FLIGHT ENGINEER AND THE FIRST OFFICER, WHO WAS FLYING THE AIRCRAFT, DONNED THEIR OXYGEN MASKS. RATHER THAN DONNING HIS OXYGEN MASK IMMEDIATELY, THE CAPTAIN ASKED THE LEAD FLIGHT ATTENDANT, WHO HAPPENED TO BE ON THE FLIGHT DECK, TO CHECK AND SEE IF THE PASSENGER OXYGEN MASKS HAD DEPLOYED. AFTER SHE REPORTED THAT THEY HAD, THE CAPTAIN ATTEMPTED TO DON HIS OXYGEN MASK. THAT ATTEMPT WAS UNSUCCESSFUL. HE BECAME HYPOXIC AND LOST CONSCIOUSNESS. THE FLIGHT ATTENDANT BECAME HYPOXIC AND LOSS CONSCIOUSNESS AT THE REAR OF THE FLIGHT DECK. THE FLIGHT ENGINEER LEFT HIS DUTY POSITION AND PLACED THE SECOND OBSERVER'S OXYGEN MASK ON THE FLIGHT ATTENDANT, WHO THEN REGAINED CONSCIOUSNESS. WHILE THIS WAS OCCURRING, THE FIRST OFFICER INITIATED THE EMERGENCY DESCENT. AFTER REGAINING CONSCIOUSNESS, THE FLIGHT ATTENDANT NOTICED THAT THE CAPTAIN WAS SLUMPED OVER, HIS OXYGEN MASK OUT OF PLACE. SHE WENT TO THE CAPTAIN'S ASSISTANCE AND PLACED HIS OXYGEN MASK ON HIS FACE. THE FLIGHT ATTENDANT THEN NOTICED THAT THE FLIGHT ENGINEER WAS SLUMPED OVER, UNCONSCIOUS, WITH HIS OXYGEN MASK OUT OF PLACE. THE FLIGHT ATTENDANT WENT TO THE FLIGHT ENGINEER'S ASSISTANCE AND PLACED HIS OXYGEN MASK ON HIS FACE. HE REGAINED CONSCIOUSNESS. IT IS NOT KNOWN HOW THE FLIGHT ENGINEER'S OXYGEN MASK BECAME DISLODGED. AFTER REGAINING CONSCIOUSNESS, THE CAPTAIN TOOK OVER CONTROL OF THE AIRCRAFT. HE DIVERTED FLIGHT #406 TO INDIANAPOLIS WHERE A LANDING WAS MADE WITHOUT FURTHER INCIDENT.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CHI96IA157](https://openairdocs.org/ntsb/CHI96IA157), May 13, 1996: Boeing 727-290 (N775AT), Indianapolis, IN, incident, no damage. Probable cause: the failure of the captain and flight engineer to utilize a checklist to troubleshoot a pressurization system problem, and the flight engineer's improper control of the pressurization system which…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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