Boeing Vertol BV-107-II N190CH

Summary

On 20 August 1983 at about 17:05 local time, a Boeing Vertol BV-107-II registered N190CH was involved in an accident near Shaver Lake, California, United States. 2 people were on board and 2 died. The aircraft was destroyed. No probable cause statement is available for this record.

Date

20 August 1983 at 17:05

Classification

Accident

Location

Shaver Lake, California, United States

Coordinates

37.1302, -119.2208

Aircraft

Boeing Vertol BV-107-II

Registration

N190CH

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Shaver Lake → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX83FA395

2 people died.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.