ERA21LA275 · Bell 206 B
Aviation Services Unlimited Bell 206 B · Accident: hard landing during autorotation
Event
- NTSB case
- ERA21LA275
- 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 206 B
- 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
- N134VG
- Operator
- Aviation Services Unlimited
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 47 years (built 1974)
- 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
- Autorotation
- Defining eventThe 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
- Hard landing
- 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
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Action/decision
- Personnel issues › Psychological
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The accident occurred during a Part 135 competency check ride for the pilot. On board were two Federal Aviation Administration (FAA) aviation safety inspectors, one seated in the left seat performing the check ride and another in the left rear seat providing oversight and on-the-job training to the other inspector. After performing maneuvers, the flight returned to the airport where the pilot was to perform a straight-in autorotation with power recovery. As the recovery began, the pilot recalled that he advanced the throttle to the full open position, which the FAA inspector confirmed by attempting to rotate the throttle to the open position, and noted the power turbine and rotor RPM needles were in the green arc. As the pilot raised the collective for recovery, the low rotor warning light and low rotor warning horn both activated. The helicopter impacted the runway hard, rotated right and rolled over on its left side with the engine still operating. The engine continued to run until the inspector in the left seat was able to reach and rotate the right throttle grip “several times” until the engine stopped. The helicopter’s fuselage was substantially damaged. Examination of the helicopter after the accident did not reveal any preaccident malfunctions or failures that would have precluded normal operation. According to the inspector in the left seat, as the pilot began the recovery and rotated the throttle, the inspector checked the throttle position, attempting to rotate the (left side) throttle grip towards the open position, and it did not move. In retrospect, the inspector considered, when he attempted to rotate the throttle grip and it did not move, that it may not have been in the fully open position and the resistance he felt in the (left) grip may have been a result of the pilot holding his (right) throttle grip tightly. The pilot had been holding the controls somewhat tightly during the flight. If the throttle were not in the fully open position during the recovery from the autorotation, the governor would not automatically maintain the rotor RPM. As the pilot raised to collective to flare, this could result in a reduction of rotor RPM and apparent partial loss of power.
Probable cause
The pilot's improper termination of a practice autorotation with power recovery, which resulted in low rotor rpm, an unstable landing, and a rollover. Contributing to the accident was the evaluator's inadequate oversight.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA275
- Event ID
- 20210629103375
- Case number
- ERA21LA275
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. 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: 0fb77ee975c331ff0a18f5328b19aece5e67aa0caf12a4af27db7149e4791473; retrieved 2026-09-16T14:14:07.135Z.