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NTSB Reports is an independent research and search tool for public aviation accident and incident records. It brings NTSB aviation reports, structured fields, docket files, extracted figures, photos, videos, and update history into one searchable interface.

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NTSB Report

March 31, 1991 · Bell BH-47G2A · N38926

Waitsburg, WA

Overview

Report Status

Probable Cause

Event Type

Accident

Date

March 31, 1991

Injury Outcomes

No injuries (1 uninjured)

Location

Waitsburg, WA

Aircraft

Bell BH-47G2A

Tail Number

N38926

Operator

Waitsburg Helicopter Service

Injuries

None

Aircraft Damage

Substantial

NTSB Number

SEA91LA077

WHILE THE PILOT WAS LOWERING THE COLLECTIVE PITCH AFTER LANDING TOUCHDOWN, THE MAIN ROTOR SEPARATED FROMT HE MAST. THE EXAMINATION REVEALED THE IMPROPER INSTALLATION OF THE MAST NUT AND LOCK WASHER WHEN THE MAIN ROTOR WAS INSTALLED.

NTSB Probable Cause

THE IMPROPER INSTALLATION OF THE MAIN ROTOR MAST NUT AND LOCK WASHER BY MAINTENANCE PERSONNEL WHICH RESULTED IN THE SEPARATION OF THE MAIN ROTOR SYSTEM.

Full Narrative

WHILE THE PILOT WAS LOWERING THE COLLECTIVE PITCH AFTER LANDING TOUCHDOWN, THE MAIN ROTOR SEPARATED FROMT HE MAST. THE EXAMINATION REVEALED THE IMPROPER INSTALLATION OF THE MAST NUT AND LOCK WASHER WHEN THE MAIN ROTOR WAS INSTALLED.

Flight

Event TypeAccident

Event Time08:15 PST

Nearest Airport0nm N

Runway0

Flight Plan FiledNone

Aircraft FireNo

Aircraft ExplosionNo

Aircraft

AircraftBell BH-47G2A

Tail NumberN38926

Aircraft CategoryHeli

DamageSubstantial

OperatorWaitsburg Helicopter Service

Operating RulePart 137

Engines1

Engine TypeReciprocating

Engine DetailsLycoming · VO-435A1F · Reciprocating · 260

Seats3

People & Injuries

Injury SummaryNo injuries (1 uninjured)

Fatal0

Serious0

Minor0

Uninjured1

Total1

Crew 1Age 45 · Second Class

Conditions

ConditionsVMC

LightDaylight

Wind340° @ 5 kt

Visibility50 sm

CeilingNone

Temperature / Dew Point46 / 39 C

Altimeter30.00 inHg

Observation Time15:45

Weather SourceWFAC

500 – Data service is offline

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March 31, 1991 · Bell BH-47G2A · N38926

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Full Narrative