# NTSB CHI88IA159: Boeing 737-130, N409PE, Indianapolis, IN, July 6, 1988

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: July 6, 1988, 18:25 local (23:25 UTC)
- Place: Indianapolis, IN
- Coordinates: 39.729709, -86.290481 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.7297&lon=-86.2905&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 36 uninjured
- Status: Completed, report June 11, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 13998
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI88IA159
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13998/pdf
- Page: https://openairdocs.org/ntsb/CHI88IA159

## Probable cause

FAILURE TO ENSURE PROPER ALIGNMENT AND CLOSURE OF THE AUXILLARY POWER UNIT LOWER SHROUD WITH THE FIRE SEAL UPON COMPLETION OF A MAINTENANCE ACTION.

## Sequence of events

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

- Airframe/component/system failure/malfunction, descent - normal
  - auxiliary power unit - fire
  - fire extinguishing equipment - initiated, pilot in command
  - maintenance,alignment - improper, company maintenance personnel (cause)

## Analysis

SCHEDULED AIR CARRIER EXPERIENCED APU FIRE WARNING WHEN APU START WAS ATTEMPTED DURING APPROACH DESCENT. INVESTIGATION REVEALED THAT EGT TEMPERATURE PROBE WIRING HARNESS WAS PINCHED BETWEEN FIRE SEAL AND LOWER APU SHROUD. FIRE SEAL COMPROMISE ALLOWED POOLED FUEL TO ENTER LOWER APU AREA AND CAUSE LOCALIZED FIRE ON DELAYED IGNITION.

## Aircraft

- Registration: N409PE (not matched to a registry record)
- Reported make and model: BOEING 737-130
- Category: Airplane
- Serial number: 19026
- Engines: P&W JT8D-17 14500 lbs thrust turbo fan
- Damage: No damage
- Fire: In-Flight
- Flight: Part 121
- Registered owner: Continental Airlines, Inc
- Airworthiness certificate: Standard, Transport
- Departed: CLE, CLEVELAND, OH
- Destination: IND, INDIANAPOLIS, IN
- Flight plan: IFR
- Airport: Indianapolis Int'L, runway 22R, 10,005 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; flight engineer, airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, unknown; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 4 knots
- Visibility: 5 statute miles
- Lowest ceiling: none
- Temperature: 88 °F, dew point 70 °F
- Altimeter: 30.00 inHg
- Observed at: IND, 30 nm away

## 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 19880706071419I](https://openairdocs.org/incident/19880706071419I), Jul 6, 1988: Boeing 737130, Indianapolis, IN. APU fire warning on attempt to start put out by fire bottle. Found pinched ignition harness.

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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