Aerospatiale AS-355F-1 N909CH

Summary

On 31 May 1986 at about 22:30 local time, a Aerospatiale AS-355F-1 registered N909CH, operated by Hemmeter Aviation, Inc., was involved in an accident near Kameula, Hawaii, United States. 5 people were on board and one had minor injuries. The aircraft was substantially damaged. No probable cause statement is available for this record.

Date

31 May 1986 at 22:30

Classification

Accident

Location

Kameula, Hawaii, United States

Coordinates

20.0408, -155.7000

Aircraft

Aerospatiale AS-355F-1

Registration

N909CH

Category

Helicopter

Engines

1

Operator

Hemmeter Aviation, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Unknown → Maui

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX86MA238

1 person had minor injuries.

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 PLT RPRTD THAT AS HE 'HOVERED' THE HELICOPTER BTN 5 & 10 FT AFTER LIFT-OFF, HE NOTED A 'SLIGHT LATERAL VIBRATION.' HE LNDD IMMEDIATELY, BUT THE VIBRATION/GROUND RESONANCE (VIB) INCREASED IN SEVERITY, SO HE 'SHUT-OFF' BOTH THROTTLES. THE VIB CONTD TO THE EXTENT THAT HE COULDN'T HOLD ONTO THE CYCLIC CTL STICK. THE TRANSMISSION SEPD FM ITS ATTACH POINT &THE MAIN ROTOR BLADES CONTACTED THE GND BFR THE ENG STOPPED. AN EXAM REVEALED THE TRANSMISSION SUPPORT BARS (TSB'S) HAD FAILED DRG THE ACDNT. THERE WAS EVIDENCE OF OVERLOAD FAILURE OF THE TSB'S, EXCEPT THE LEFT FWD TSB HAD EVIDENCE OF FA- TIGUE ON EITHER SIDE OF THE BUCKLED AREA. A STRIATION COUNT INDCD THE CRACK HAD PROGRESSED OVR AN ESTD TIME OF AT LEAST 1 HR & 15 MIN. ALSO, AN ARM OF THE STARFLEX ASSY (S/A) HAD FAILED. THE S/A HAD 323 HRS SINCE RPLCMNT. CRAZE CRACKS WERE FND ON THE S/A, BUT AN EXAM FAILED TO VERIFY WHETHER THEY HAD FORMED BFR OR DRG THE ACDNT. THE S/A WAS APRX 3% POROUS & HOLES IN THE ENAMEL BARRIER ALLOWED ENVIRONMENTAL BLACKENING OF ITS EDGES. LNDG SKID SHOCK ABSORBERS WERE BADLY DMG.

Quoted verbatim from the NTSB record.