Aerospatiale AS350BA N5793P

Summary

On 14 November 2009 at about 10:01 local time, a Aerospatiale AS350BA registered N5793P, operated by Mountain Lifeflight, was involved in an accident near Doyle, California, United States. 3 people were on board and 3 died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

14 November 2009 at 10:01

Classification

Accident

Location

Doyle, California, United States

Coordinates

39.8514, -120.3500

Aircraft

Aerospatiale AS350BA

Registration

N5793P

Category

Helicopter

Engines

1

Operator

Mountain Lifeflight

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Reno → Susanville

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

WPR10FA055

3 people died.

The pilot became spatially disoriented while maneuvering on a dark night, which resulted in a loss of helicopter control.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Ten minutes after dropping off a patient at the local hospital and while returning to home base in dark night conditions, the flight crew made a routine position report. About 8 minutes later, the flight crew transmitted that the helicopter was going down. Radar data indicated that after departure from the hospital, the helicopter initiated a climb from about 4,500 feet mean sea level (msl) and established a northwesterly course. In the vicinity of the accident site, the target indicated a climbing turn to the northeast followed by a turn to the southwest, and then a climbing turn back to the northeast. The last two targets indicated a turn to the right. The last recorded altitude was at 10,200 feet msl. On-site documentation of the wreckage suggested that the helicopter was in a nose-low attitude and about a 90-degree bank angle when it contacted the ground. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A study of the weather conditions in the vicinity of the accident site indicated clouds were present with tops reaching about 13,000 feet msl. Light clear icing was present with the potential for moderate clear icing in or near clouds. Visibility was at or greater than 10 statute miles. Given the helicopter’s flight path shortly before the accident, it is likely that the pilot was maneuvering to avoid clouds and became disorientated in the dark night conditions, which resulted in a loss of helicopter control.

Quoted verbatim from the NTSB record.