Accident Bell 206L-1 LongRanger II N523RR,
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ASN Wikibase Occurrence # 42666
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Date:Friday 26 July 1991
Type:Silhouette image of generic B06 model; specific model in this crash may look slightly different    
Bell 206L-1 LongRanger II
Owner/operator:Rogers Helicopters Inc
Registration: N523RR
MSN: 45231
Fatalities:Fatalities: 1 / Occupants: 1
Aircraft damage: Destroyed
Location:Stanislaus National Forest, Lake Alpine, Alpine County, California -   United States of America
Phase: Manoeuvring (airshow, firefighting, ag.ops.)
Nature:Fire fighting
Departure airport:Bear Valley, Alpine County, California
Destination airport:Stanislaus National Forest, Lake Alpine, Alpine County, California
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Written off (damaged beyond repair) July 26 1991 when crashed whilst involved in fire fighting duties in the Satanislaus National Forest, at Lake Alpine, a reservoir in Alpine County, California, formed by Alpine Dam on Silver Creek. It is located east of Bear Valley in the Sierra Nevada range. According to the following published source (see link #3):

"Incident Name: small holdover lightning fire -- the Pine Fire -- on the Stanislaus National Forest

Date: July 26 1991, about 17:00 hours
Personnel: Gifford Keeth
Age: 58
Agency/Organization: Rogers Helicopters of Clovis, under contract to the Forest Service
Position: pilot

Summary: During a landing approach out of ground effect, the Bell 206 helicopter descended into the vortices created by the main rotor blades and lost main rotor lift. The helicopter descended, struck trees and impacted nose down, killing Giff. The National Transportation Safety Board did not investigate this incident.

Forest Service Investigations - Fatal Aviation Accident History (1974-2002): Pages 67-68 for this incident
Forest Service Investigation Probable Cause:

In developing a probable cause to this mishap, the investigation team stated that the flight profile of the final approach to land the load in the opening was conducive to the helicopter entering into a main rotor vortex ring state that was aggravated by a shift in direction or down draft in the wind. This could have caused a descent beyond the pilot’s capability to arrest in the vertical space available to perform an escape maneuver. They deemed the mishap was caused by the strike of the main rotor blade near the top of a tree.

Note: Prior to 1996 NTSB did not investigate Gov owned and operated, Gov owned and contractor operated or some aircraft that were privately owned and operated as "public aircraft". Government agency investigations and reports were/are often hard to find and access. The "Pressler Act", passed in 1995 and enacted in 1996, changed that, making all aircraft accident reports easier to access and lessons easier to learn."


1. NTSB Identification: LAX91TL#08 at
2. FAA:

Revision history:

24-Oct-2008 10:30 ASN archive Added
20-Apr-2016 19:01 Dr.John Smith Updated [Time, Operator, Location, Nature, Departure airport, Destination airport, Source, Narrative]
21-Dec-2016 19:24 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]

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