Skip to content

CHI91IA078

1991-01-20 · ST. PAUL, Minnesota, United States · None · 1 aircraft · Status: Completed

Airport MSP

Aircraft involved

Probable cause & findings

THE PARTIAL FAILURE OF THE AIRPLANE'S AUXILIARY POWER UNIT, AND THE INADEQUATE COMPONENT PRODUCED BY THE MANUFACTURER.

Factual narrative

THE FLIGHT CREW WAS INFORMED BY THE TOWER OF A FIRE ON THE RIGHT SIDE OF THE AIRPLANE WHILE TAXIING FOR TAKEOFF. THE FIRE PRECEEDED BY UTILIZING THE AUXILARY POWER UNIT (APU) FOR A MAIN ENGINE START. THE MAIN ENGINE START WAS ABORTED WHEN THE APU FAILED TO DELIVER SUFFICIENT BLEED AIR PRESSURE. A POST INCIDENT INSPECTION OF THE APU DISCLOSED A LIBERATED TURBINE EXDUCER BLADE WHICH CAUSED AN IMBALANCE OF THE TURBINE WHEEL, ALLOWING SMOPKE AND FLAMES TO ESCAPE FROM THE APU EXHAUST ATOP THE RIGHT WING ROOT. THERE HAS BEEN 7 SERVICE DIFFICULTY REPORTS AND 4 ACCIDENTS/INCIDENTS ASSOCIATED WITH EXDUCER FAILURES IN THIS MODEL APU IN THE LAST FIVE YEARS. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1991_CHI91IA078.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Search this event elsewhere

External sources are reported, not agency: signal that something happened, not fact about what happened.