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Atlas / NTSB / SEA91LA260

NTSB CAROL · Event

Event SEA91LA260

1991-04-14 GRANGEVILLE, Idaho, United States Fatal 1 aircraft Status: Completed

Aircraft involved

Probable cause & findings

THE IMPROPER DECISION BY THE PILOT TO CONTINUE VFR FLIGHT IN IMC WEATHER CONDITIONS IN MOUNTAINOUS TERRAIN, RESULTING IN PILOT DISORIENTATION AND INADVERTENT FLIGHT INTO A BOX CANYON. FACTORS RELATING TO THE ACCIDENT WERE THE RAIN SHOWERS AND LOW CEILING WEATHER CONDITIONS, AND THE BOX CANYON IN MOUNTAINOUS TERRAIN.

Factual narrative

THE FLT ENCOUNTERED LOW CEILINGS AND RAIN SHOWERS ON A VFR FLT THRU REMOTE HIGH ALT MT. TERRAIN. THE PILOT INADVERTANTLY ENTERED A BOX CANYON AND ATTEMPTED TO REVERSE COURSE. THE ACFT IMPACTED TERRAIN ON THE SIDE OF THE CANYON AT 7100 FT MSL. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1991_SEA91LA260.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.