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CHI91IA058

1991-01-03 · DES MOINES, Iowa, United States · Minor · 1 aircraft · Status: Completed

Airport DSM

Aircraft involved

Probable cause & findings

AN OIL LEAK ORIGINATING FROM THE AUXILIARY POWER UNIT WHICH CREATED SMOKE IN THE PASSENGER CABIN AFTER IT PASSED THROUGH THE AIR CONDITIONING/HEATING SYSTEM EQUIPMENT AND ASSOCIATED DUCT WORK.

Factual narrative

THE AIRPLANE WAS TAXIING TO ITS ASSIGNED GATE AFTER LANDING WHEN A FLIGHT ATTENDENT INFORMED THE CAPTAIN THAT THERE WAS A FIRE IN THE REAR OF THE AIRPLANE. THE CAPTAIN IMMEDIATELY STOPPED AND THE PASSENGERS WERE DEPLANNED USING THE COMPANY'S EMERGENCY EVACUATION PROCEDURES. A FLIGHT ATTENDENT AND ONE PASSENGER RECEIVED MINOR INJURIES DURING THE EVACUATION PROCESS. NINETH-SIX PASSENGERS AND SIX OTHER AIRPLANE CREWMEMBERS DID NOT RECEIVE INJURIES. A FIRE WAS NOT PRESENT, SMOKE HAD BEEN FILLING THE PASSENGER CABIN. THE SMOKE CAME FROM THE AIR CONDITIONING/HEATING SYSTEM DUCTS. THE SMOKE WAS A RESULT OF AN OIL LEAK IN THE AIRCRAFT POWER UNIT (APU) WHICH ENTERED THE APU DUCT WORK, THE AIR CONDITIONING PACKS AND ASSOCIATED CIRCULATION DUCTING. WHEN A CERTAIN HEAT RANGE HAD BEEN SELECTED THE OIL LADEN AIR WOULD CHANGE INTO SMOKE AS IT EXITED THE CABIN HEAT DUCT OPENING. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1991_CHI91IA058.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

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