ASN logo
ASN Wikibase Occurrence # 70071
Last updated: 26 April 2019
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Type:Silhouette image of generic AS50 model; specific model in this crash may look slightly different
Aérospatiale AS 350BA Ecureuil
Owner/operator:Mountain Lifeflight
Registration: N5793P
C/n / msn: 1476
Fatalities:Fatalities: 3 / Occupants: 3
Aircraft damage: Substantial
Location:1/4 mile W of Highway 395, near Doyle, Lassen County, California -   United States of America
Phase: En route
Departure airport:Reno, NV
Destination airport:Susanville, CA (SVE)
Investigating agency: NTSB
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.
Probable Cause: The pilot became spatially disoriented while maneuvering on a dark night, which resulted in a loss of helicopter control.


FAA register: 2. FAA:

Revision history:

14-Nov-2009 12:05 RobertMB Added
14-Nov-2009 20:51 RobertMB Updated
17-Nov-2009 11:03 JINX Updated
17-Nov-2009 11:04 JINX Updated
27-Jul-2014 01:06 Dr. John Smith Updated [Time, Location, Departure airport, Destination airport, Source, Narrative]
27-Jul-2014 01:10 Dr. John Smith Updated [Time, Narrative]
21-Dec-2016 19:25 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
02-Dec-2017 17:49 ASN Update Bot Updated [Other fatalities, Departure airport, Destination airport, Source, Narrative]

Corrections or additions? ... Edit this accident description