NTSB CHI91LA300 — 1991-09-14 · MUSKEGON, Michigan, United States

N243AT has since been reassigned. It is now registered to a different aircraft (PIPER PA-44-180, built 2000), which was not involved in this event.

Aircraft involved

N243AT ATR ATR 42-300 Serious

Probable cause & findings

THE FAILURE, FOR REASONS UNKNOWN, OF THE NUMBER FOUR BEARING IN THE HIGH PRESSURE SPOOL OF THE ENGINE.

Factual narrative

DURING CRUISE FLIGHT SMOKE ENTERED THE CABIN AND COCKPIT. THE CREW MADE A PRECAUTIONARY LANDING. THE FLIGHT ATTENDANT COMMANDED AN EVACUATION, ON THE CAPTAIN'S ORDER, THROUGH THE REAR EXITS OF THE AIRCRAFT. ONE PASSENGER SUSTAINED SERIOUS INJURIES (A BROKEN ANKLE) DURING THE EVACUATION. SUBSEQUENT INVESTIGATION REVEALED A FAILED BEARING IN THE LEFT ENGINE. A SHAFT SHIFTED AND ALLOWED THE DESTRUCTION OF AN OIL SEAL. OIL ENTERED THE CABIN AIR SYSTEM AND WAS EMITTED IN TO THE CABIN AND COCKPIT AS SMOKE. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1991_CHI91LA300.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

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