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Atlas / NTSB / CHI89FA109

NTSB CAROL · Event

Event CHI89FA109

1989-06-16 SAINT CHARLES, Illinois, United States Airport · DPA None 1 aircraft Status: Completed

Aircraft involved

Probable cause & findings

THE FAILURE OF THE MECHANIC TO PROPERLY INSPECT THE ALTERNATE AIR DOOR DURING ANNUAL INSPECTION. THIS FAILURE LED TO AIR STARVATION, LOSS OF POWER, AND A FORCED LANDING BY THE PILOT ONTO ROUGH TERRAIN.

Factual narrative

THE PILOT TAXIED AND TOOK OFF WITHOUT DIFFICULTY, BUT NOTICED A GRADUAL LOSS OF MANIFOLD PRESSURE AS HE WAS PREPARING TO RETRACT THE GEAR. HE LANDED IN A NEARBY FIELD WITHOUT INCIDENT, BUT DURING ROLLOUT, THE AIRCRAFT STRUCK A DITCH, DRIVING THE RIGHT GEAR THROUGH THE WING SURFACE. INSPECTION REVEALED THE ALTERNATE AIR DOOR HAD BROKEN FREE AND WAS SUCKED DOWN THE INTAKE TO THE FUEL CONTROLLER, RESTRICTING THE AIR FLOW. ONLY TWO HOURS HAD ELAPSED SINCE THE ANNUAL INSPECTION. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1989_CHI89FA109.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.