DEN00FA074 · Bell 206L-3
Bell 206L-3 · Accident: airframe, component or system failure en route
From McElroy Airfield (20V) to Centennial Airport (APA)
Event
- NTSB case
- DEN00FA074
- 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 206L-3
- 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
- N937S
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From McElroy Airfield (20V), Kremmling, COTo Centennial Airport (APA), Englewood, CO
- 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 · descent
- 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
- Rotor system, tail rotor blade › Failure, total
- Rotor system, tail rotor blade › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During initial descent at the completion of a cross-country flight, the pilot heard a loud bang from the rear of the helicopter and manipulation of the tail rotor control became ineffective. The pilot performed an autorotation to a landing in a field, which sloped up about 6 degrees and was rough and uneven. During landing with about 5 knots forward speed, the lower wire cutter dug into the ground and the skids collapsed twisting the cross tubes aft. The main rotor blades were not damaged and the tail booms buckled downward at the forward attach point. The pilot performed a normal shut down and he and his passenger exited the helicopter with no injuries. Examination of the helicopter following the event revealed that both tail rotor blades had separated approximately 9 inches outboard of the hub. Laboratory tests revealed that one tail rotor blade failed from fatigue. The fatigue origin occurred at the protective strip trailing edge inboard of the outboard tip of the blade doubler. Inspection at the origin revealed the fatigue was a result of chemical machining/etching that took place during the manufacturing process.
Probable cause
The complete loss of the tail rotor blades due to a fatigue failure of one blade. Factors were sloping and rough uneven terrain for the ensuing forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN00FA074
- Event ID
- 20001212X20793
- Case number
- DEN00FA074
- 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: 6bc8c065820872eac23c8e10117705f9deae731af8a6c2ee88d41594be37e826; retrieved 2026-09-22T12:57:59.589Z.