# NTSB ATL89IA099: Boeing 737-201, N217US, Dayton, OH, March 9, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: March 9, 1989, 17:13 local (22:13 UTC)
- Place: Dayton, OH
- Location: 39.7589° N, 84.1916° W: Placed by OpenAirDocs: center of Dayton, OH, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.7589&lon=-84.1916&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 82 uninjured
- Status: Completed, report August 26, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 7928
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89IA099
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7928/pdf
- Page: https://openairdocs.org/ntsb/ATL89IA099

## Probable cause

AN EXCESSIVELY WORN OUTFLOW VALVE IN THE CABIN EVIRONMENTAL/PRESSURIZATION SYSTEM THAT RESULTED IN A RAPID CABIN DEPRESSURIZATION.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Decompression, cruise - normal
  - air cond/heating/pressurization,outflow valve - dumped (cause)

## Analysis

A PASSENGER DIED AFTER A RAPID DECOMPRESSION AND EMERGENCY DESCENT. THERE WAS NO DAMAGE TO THE AIRPLANE OR INJURY TO THE REMAINING OCCUPANTS OF THE AIRPLANE. AN INVESTIGATION REVEALED THAT AN UNCONTROLLABLE OUTFLOW VALVE RESULTED IN A RAPID DECOMPRESSION AT FL 310. THE OXYGEN MASKS DEPLOYED & THE CPT MADE AN EMERGENCY DESCENT TO 10,000 FT, THEN CONTINUED TO DAYTON, LANDING AT 1740. THE PASSENGER WAS TAKEN TO A DAYTON HOSPITAL AND DIED AT ABOUT 6 HOURS AND 50 MINUTES LATER. THE MONTGOMERY COUNTY CORONER RULED THAT DEATH WAS DUE TO NATURAL CAUSES.

## Aircraft

- Registration: [N217US](https://openairdocs.org/deregistered/N217US-2000-07-20), registration cancelled 2000-07-20, S/N 20215 (OpenAirDocs)
- Reported make and model: BOEING 737-201
- Registry model: [Boeing 737-201](https://openairdocs.org/model/boeing-737-201) (registry code 1384454) (OpenAirDocs)
- Category: Airplane
- Serial number: 20215
- Airframe hours: 49548
- Engines: P&W JT8D-9A 20500 lbs thrust turbo fan
- Damage: No damage
- Flight: Part 121
- Registered owner: Piedmont Aviation
- Airworthiness certificate: Standard, Transport
- Departed: TPA, TAMPA, FL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 12,800 total, 2,500 in this make and model

## Weather

- Conditions: Day

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19890309003999I](https://openairdocs.org/incident/19890309003999I), Mar 9, 1989: Boeing 737201, Dayton, OH. Lost control of pressurization system. Emergency descent. Found a faulty outflow valve.

## Other investigations on N217US (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 FTW97LA177](https://openairdocs.org/ntsb/FTW97LA177), May 4, 1997: Boeing 737-201 (N217US), Denver, CO, no damage. Probable cause: The flight attendant's failure to assure that the jetway was placed in the proper position prior to opening the forward cabin entry door.

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.

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