2 fatalities

2004-08-17: Beechcraft 99 Airliner (N199GL) — Alpine Air — Mt Big Baldy, United States of America

Mt Big Baldy, United States of AmericaFlight

On August 17, 2004, a Beechcraft 99 Airliner (registration N199GL) operated by Alpine Air was involved in an aviation accident near Mt Big Baldy, United States of America in flight. 2 people were killed. Investigators recorded the probable cause as: The pilot's failure to maintain adequate terrain clearance during cruise, which resulted in the in-flight collision with mountainous terrain. Dark night conditions and mountainous terrain were contributing factors. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781200186Data APIEditorial standards

A non-scheduled Part 135 VFR flight struck a mountain at about 9,100 feet MSL during dark night conditions. The pilot had reported level at 8,500 feet. No mechanical issues were found.

Accident Overview

During the return leg of a non-scheduled 14 CFR Part 135 VFR cross-country flight, the airplane collided with mountainous terrain at approximately 9,100 feet above mean sea level. Before the accident, the pilot informed air traffic control that he was operating under visual flight rules (VFR) and maintaining level flight at 8,500 feet MSL. The accident occurred under dark night conditions. The aircraft impacted the south-facing slope of a 9,100-foot mountain, near the last recorded radar position. Wreckage and impact signatures at the crash site were consistent with a high-energy, shallow-angle collision with the terrain.

Investigation Findings

The investigation found no evidence of any mechanical problems with the aircraft. The terrain and lighting conditions were examined as part of the inquiry. The pilot's reported altitude of 8,500 feet MSL was below the elevation of the mountain (9,100 feet), indicating insufficient terrain clearance during the cruise phase of flight.

Probable Cause

The probable cause of the accident was the pilot's failure to maintain adequate terrain clearance during cruise, which resulted in the in-flight collision with mountainous terrain. Dark night conditions and mountainous terrain were contributing factors.