Aircraft Accident/Incident Report

Shaver Lake, California 93664
Saturday, August 20, 1983 10:05 PDT

NTSB Narrative Summary Released at Completion of Accident

THE ONLY WITNESS, THE HOOKER, WHO GETS LOGS READY FOR TRANSPORT BY THE HELICOPTER, STATED THAT HE HEARD NOISES AND THE ROTOR BLADES BEGAN COMING APART AS THE ACFT STARTED DOWNHILL WITH A LOG. EXAMINATION OF THE WRECKAGE REVEALED THAT #3 SYCHRONIZING SHAFT (BOEING P/N 10703141-13) HAD FAILED A FATIGUE CRACK ORIGINATING AT A RIVET HOLE. THE TOTAL TIME ON THE SHAFT WAS 17492 HOURS WITH 435 HOURS SINCE OVERHAUL. THE QUALITY OF THE SURFACE FINISH ON THE RIVET HOLES WAS CONSIDERED UNSATISFACTORY IN A POST ACCIDENT LABORATORY EVALUATION. AS A INTERIM MEASURE BOEING VERTOL ARBITRAILY IMPOSED A LIFE OF 8750 HOURS ON ALL SYNCHRONIZING SHAFTS OF THIS TYPE. THIS WAS BASED ON THE LIFE OF THIS FAILED PART. A PROGRAM IS ALSO BEING DEVELOPED TO DO A FLT STRAIN SURVEY ON A BV-107 FOR LOGGING OPERATIONS. THE HOOKER STATED THAT THE LOG BEING LIFTED BY THE ACCIDENT ACFT WEIGHED BETWEEN 8000 AND 9000 POUNDS.

NTSB Probable Cause Narrative

Not Yet Reported

Event Information

Type of Event Accident
Event Date 8/20/1983
Event Day of the Week Saturday
Time of Event 1005
Event Time Zone Pacific Daylight Time
Event City SHAVER LAKE
Event State CALIFORNIA
Event Country --
Zipcode of the event site 93664
Event Date Year 1983
Event Date Month 8
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Not pertinent
Investigator's weather source Witness
Time of the weather observation 950 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 225
Weather Observation Facility ID FAT
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 35
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 50
Air Temperature at event time (in degrees celsius) 16
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 250
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) 7425
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 2694
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 22993
Date of most recent change to record Jan 2 2001 9:15AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N190CH
NTSB Number LAX83FA395
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 133: Rotorcraft Ext. Load
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BOEING VERTOL
Aircraft Model BV-107-II
Aircraft Series Identifier BV-107-II
Aircraft Serial Number 2002
Certified Max Gross Weight 13500
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 2
Number of Engines 2
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection Aug 18 1983 12:00AM
Airframe hours since last inspection 8
Airframe Hours 2392
ELT Installed Unknown
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name COLUMBIA HELICOPTERS LEASING
Aircraft Owner Street Address PO BOX 3500
Aircraft Owner City PORTLAND
Aircraft Owner State OR
Aircraft Owner Country
Aircraft Owner Zipcode 97208
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation External Load
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code
Departure City SHAVER LAKE
Departure State CA
Departure Country
Departure Time 630
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:31AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --