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LAX94LA075 · Bell 206B-III

10 Dec 1993 · Flagstaff, AZ, United States

Bell 206B-III · Accident: airframe, component or system failure en route

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Event

NTSB case
LAX94LA075
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
0 · 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 206B-III

Aircraft type
Bell 206
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
N2773R
Operator
Warren Smith
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 91: General Aviation
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
En route · cruise
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
Substantial

Cause areas

  • Pilot in command › Emergency procedure, improper use of

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

NTSB narrative

FOLLOWING AN ANNUAL INSPECTION, THE HELICOPTER HAD EXPERIENCED AN INTERMITTENT ILLUMINATION OF THE 'ENGINE OUT' ANNUNCIATOR LIGHT. THE PILOT CONTINUED FLYING AND MONITORED THE ENGINE INSTRUMENTS, PARTICULARLY THE N2 POWER TURBINE GAUGE. DURING THE ACCIDENT FLIGHT, THE ANNUNCIATOR AGAIN FLICKERED AND THEN STAYED ON. IN ADDITION, THE 'ENGINE OUT' HORN ALSO SOUNDED; HOWEVER, THE ENGINE PARAMETERS REMAINED NORMAL. THE ANNUNCIATOR LIGHT AND HORN WILL ACTIVATE IF THE N1 GAS PRODUCER FALLS BELOW 55 PERCENT. THE PILOT REPORTED THAT DURING A TURN, THE N2 BEGAN DECREASING AND HE ENTERED AN AUTOROTATION. THE HELICOPTER ROLLED OVER FOLLOWING A HARD LANDING. POSTACCIDENT TESTS REVEALED THAT THE ENGINE OPERATED WITHIN NORMAL SPECIFICATIONS. THE N2 TACH GENERATOR OPERATED NORMAL. THE N1 TACH GENERATOR FAILED.

Probable cause

The pilot's improper initiation of an emergency autorotation into unsuitable terrain and subsequent hard landing and rollover. A false annunciator indication, a failure of the N1 tach generator, the pilot's continued flight with a known aircraft defect, and the pilot's improper identification of the failed N1 gauge were factors in this accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX94LA075
Event ID
20001211X13878
Case number
LAX94LA075
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: local date, investigation status. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1993-12-11.
  • API snapshot SHA-256: 7fb0ebc8876a051a24fbc96a657767ef4ac39172ea28365b2b6c2c748a39faee; retrieved 2026-09-23T01:26:15.403Z.