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ANC93FA056 · Bell 204B

2 May 1993 · COPPER HARBOR, AK, United States

Bell 204B · Accident: airframe, component or system failure while maneuvering

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Event

NTSB case
ANC93FA056
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
1 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Bell 204B

Aircraft type
Bell 204
Category
Helicopter
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N204AQ
Operator
Chester C. Rasberry · private individual
Onboard fatalities
Unknown
Route
From not recordedTo not recorded
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 133: Rotorcraft Ext. Load
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Maneuvering · hover
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Airframe, component or system failure
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Destroyed

Cause areas

  • Company/operator management › Rotorcraft operations, excessive
  • Rotor drive system, tail rotor gearbox(90 deg) › Fatigue

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

AEROLOGGING OPERATION REQUIRED A STEEP DESCENT FLIGHT PATH FROM THE LOG PICKUP SITE AT 1200 FT ELEVATION TO THE LANDING SITE AT 70 FT ELEVATION. DESCENT ESTIMATED TO TAKE 11-12 SECS, AND DESCRIBED AS 'STRAIGHT DOWN IN AUTOROTATION AND DROPPING THE LOGS.' PILOT EXPRESSED RESERVATIONS ABOUT 'BEING ABLE TO DO IT.' FOLLOWING A DESCENT, AND WHILE IN A HOVER, THE TAIL ROTOR & 90 DEG GEAR BOX SEPARATED. METALLURGICAL EXAM REVEALED FATIGUE SIGNATURES ON GEAR BOX CASE STUDS. GEAR BOX OF MILITARY ORIGIN. RECORDED WEIGHTS INDICATED THAT THE AIRCRAFT HAD BEEN OPERATING IN EXCESS OF THE GROSS WEIGHT HOOK LIMIT. THERE WAS NO RECORD OF SURVEILLANCE BY THE POI OR PMI FROM THE FAA OFFICE HOLDING THE OPERATOR'S CERTIFICATE.

Probable cause

FATIGUE FAILURE OF THE TAIL ROTOR GEARBOX, AND IMPROPER HELICOPTER OPERATIONS BEING CONDUCTED BY THE OPERATOR RESULTING IN REPETITIVE AT AND OVER MAXIMUM LOADS. FACTORS IN THE ACCIDENT WERE: MATERIAL DEFECT OF THE TAIL ROTOR GEAR BOX (INADEQUATE QUALITY CONTROL) BY THE COMPANY/OPERATOR, AND INADEQUATE SURVEILLANCE OF BOTH THE COMPANY OPERATIONS AND MAINTENANCE FACILITY BY THE FAA.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ANC93FA056
Event ID
20001211X12256
Case number
ANC93FA056
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 984f32d7eb4bed8cb2ca2f55ec0340494c933ec3293d60cd7a06fcad0c151b9d; retrieved 2026-09-21T00:34:39.051Z.