DEN00GA050 · Bell OH-58A+
Bell OH-58A+ · Accident: loss of control in flight while maneuvering
From Skypark Airport (BTF) to an unrecorded destination
Event
- NTSB case
- DEN00GA050
- 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
- 2 · 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 OH-58A+
- Aircraft type
- Bell OH-58
- 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
- N7UT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Skypark Airport (BTF)To 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
- Maneuvering
- 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
- Loss of control in flight
- 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
- Pilot in command › Aircraft control, not maintained
- Pilot in command › Procedures/directives, not followed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot of the helicopter was to perform an autorotation during a maintenance flight to perform a functional check of the free-wheeling unit. A witness observed the helicopter at 100 to 150 feet agl, and he said that the main rotor blades 'stopped' and the aircraft started a slow spiral to the left, nose down. He further said that the helicopter was shaking violently, and its skids were flexing in and out. Postcrash examination revealed that the fuel control pointer, on the fuel control, was slightly above flight idle. Both cockpit throttles were observed positioned in slightly above the flight idle position. The helicopter's power analyzer and recorder (PAR) documented that at the time of impact, the engine's torque (TRQ) was at 13.5% and the main rotor speed (NR) was at 65.8%. The procedure for a power recovery from an autorotation is to smoothly roll throttle back on, confirm rotor and N2 needles are joined and in normal operating range, and simultaneously pull up collective while applying left pedal.
Probable cause
The pilot's failure to roll throttle back on (return the power to the normal operating range) during an attempted power recovery from an autorotation, and his subsequent failure to maintain aircraft control.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN00GA050
- Event ID
- 20001212X20478
- Case number
- DEN00GA050
- 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: b4666ecafef1be7f1f59b4d1b879da3dc59b0ecd84d3911d7f38674fbb291350; retrieved 2026-09-20T21:27:37.943Z.