Accident Details
The pilot was attempting the VOR-B instrument approach to Butte, Montana Airport. The pilot reported over the Coppertown VORTAC inbound on the airport. The procedure turn inbound course to the VORTAC is 124°, and the inbound course to the airport is 094°. The aircraft wreckage was discovered on the 124° radial 5 miles southwest of the airport. The wind was reported as 340° at 9 knots. The VOR-B approach terminates at runway 11. Runway 33 is 9,000 feet long and equipped with medium intensity runway lights (MIRLs) and runway end identifier lights (REILs). The pilot, the sole occupant, was killed.
Investigation
The official investigation identified two occurrences. The first was an in-flight encounter with weather during the approach phase. The weather conditions included a low ceiling and snow. The investigation found that the pilot made poor in-flight planning and decision-making, and did not follow instrument flight rules (IFR) procedures. The second occurrence was an in-flight collision with terrain during the approach phase. The terrain was mountainous and hilly. The investigation determined that the pilot’s altitude was improper, clearance was not possible, and there were issues with visual/aural perception.
Probable Cause
The probable cause, as stated in the official findings, is as follows:
- Occurrence #1: in flight encounter with weather; Phase of operation: approach; Findings: (f) weather condition - low ceiling; (c) in-flight planning/decision - poor - pilot in command; (f) weather condition - snow; (c) IFR procedure - not followed - pilot in command.
- Occurrence #2: in flight collision with terrain/water; Phase of operation: approach; Findings: (f) terrain condition - mountainous/hilly; (c) altitude - improper - pilot in command; (c) clearance - not possible - pilot in command; (f) visual/aural perception - pilot in command.