Bishop Airport
Aircraft Accident/Incident Report

Bishop, California 93514
Sunday, September 29, 2002 8:54 PDT

NTSB Narrative Summary Released at Completion of Accident

The helicopter was performing a hydraulic actuator check for the first flight of the day. The collective had been placed in the down position, the collective lock was engaged, and the rotor powered up to 100 percent flight idle. After depressing the hydraulic test switch, the pilot moved the cyclic fore and aft to confirm there was pressure remaining in the accumulators for a few control movements. The collective rose uncommanded and the helicopter moved forward in a nose down attitude. The main rotor struck the ground and the helicopter made two revolutions before rolling over onto its side, destroying both the main and tail rotor systems. A small fire ensued in the exhaust area, but was quickly extinguished. Examination of the collective locking mechanism (P/N 350A-27 3455-20 and P/N 350A-27 3107-26) found that it failed to hold the collective in the full down position due to wear on the locking tab. During servo accumulator checks, movement of the cyclic control after accumulator depletion caused the collective to move due to feedback in the control system. The locking device disengaged and the collective increased causing the aircraft to move.

NTSB Probable Cause Narrative

the disengagement of the collective locking mechanism due to component wear.

Event Information

Type of Event Accident
Event Date 9/29/2002
Event Day of the Week Sunday
Time of Event 854
Event Time Zone Pacific Daylight Time
Event City Bishop
Event State CALIFORNIA
Event Country --
Zipcode of the event site 93514
Event Date Year 2002
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 372222N
Event Location Longitude 1182149W
Event Location Airport Bishop
Event Location Nearest Airport ID BIH
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 4120
Weather Briefing Completeness Full
Investigator's weather source Weather Observation Facility
Time of the weather observation 856 Pacific Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID KBIH
Elevation of weather observation facility 4120
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 7
Dew Point at event time (in degress fahrenheit) -1
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 9
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.93
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 4
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 17742
NTSB Notification Source FAA
NTSB Notification Date Sep 29 2002 12:00AM
NTSB Notification Time 915
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jun 8 2005 12:51PM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office RENO, NV FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N352SA
NTSB Number LAX02TA299
Missing Aircraft Indicator --
Federal Aviation Reg. Part Public Use
Type of Flight Plan filed VFR
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Eurocopter
Aircraft Model AS350-B3
Aircraft Series Identifier --
Aircraft Serial Number 3348
Certified Max Gross Weight 4961
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 6
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Aug 16 2002 12:00AM
Airframe hours since last inspection 86
Airframe Hours 736
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Sun Air Aviation, LLC
Aircraft Owner Street Address 50 Durley Ave.
Aircraft Owner City Camarillo
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 93010
Operator is an individual? No
Operator Name US Dept of Agriculture, US Forest Service
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 3833 S. Development Ave.
Operator City Boise
Operator State ID
Operator Country USA
Operator Zip code 83705
Operator Code --
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation External Load
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Public Use
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code BIH
Departure City Bishop
Departure State CA
Departure Country USA
Departure Time 858
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code O57
Destination City Bridgeport
Destination State CA
Destination Country USA
Specific Phase of Flight Standing - idling rotors
Report sent to ICAO? No
Evacuation occurred Yes
Date of most recent change to record --
User who most recently changed record --
Since inspection or accident --
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --