ERA21LA335 · Hummer 260L
Hummer 260L · Accident: loss of engine power (total) during initial climb
Event
- NTSB case
- ERA21LA335
- 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
Hummer 260L
- Aircraft type
- Hummer 260
- 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
- N777TC
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 3 years (built 2018)
- 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
- Initial climb
- 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
- Loss of engine power (total)
- 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
- Not determined › Not determined
- Personnel issues › Action/decision
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot initiated takeoff in the helicopter, and when passing through effective translational lift, with an airspeed between 40 and 50 knots, and about 100 to 150 ft above ground level (agl), the engine experienced a sudden complete loss of power. He lowered the collective, made a partial throttle reduction, and entered an autorotation, but engine power increased when the helicopter was at 70 to 75 ft agl and 50 knots. He increased the throttle, and the engine power increased to full rpm. As he increased collective, the engine “sputtered and quit instantly.”
The helicopter was operating in the shaded area of the helicopter’s height/velocity diagram, which, according to guidance, may not allow sufficient time or altitude to enter a stabilized autorotative descent. Although the pilot rapidly lowered the collective to gain energy in the main rotor blades, there was not enough inertia in them for a normal autorotative landing. The helicopter landed hard on soft wet terrain resulting in structural damage to one of the steel tubes that attached the tailboom.
During postaccident examination of the helicopter and its engine, one fuel injector nozzle flowed slightly less than the other five; however, it likely did not contribute to the twice-repeated total loss of engine power. The examination of the engine and its systems revealed no other evidence of preimpact failure or malfunction. The reason for the twice-repeated total loss of engine power could not be determined based on the available evidence.
Probable cause
A total loss of engine power for reasons that could not be determined. Contributing to the accident was the pilot’s operation of the helicopter in a flight regime that would not allow for a successful autorotative landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA335
- Event ID
- 20210823103738
- Case number
- ERA21LA335
- 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: ecb19b276607c708790b239b783ee8553ee97af8f98f6a64cbccc1b41c6d6df1; retrieved 2026-09-16T14:26:43.300Z.