LAX03LA235 · Robinson R44
Robinson R44 · Accident: partial loss of engine power (non-mechanical) en route
From Flagstaff Pulliam Airport (FLG) to Payson Airport (PAN)
Event
- NTSB case
- LAX03LA235
- 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
- Unknown
- 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
Robinson R44
- Aircraft type
- Robinson R44
- 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
- N8329B
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Flagstaff Pulliam Airport (FLG), Flagstaff, AZTo Payson Airport (PAN), Payson, AZ
- 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
- Partial loss of engine power (non-mechanical)
- 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
- Fuel system › Blocked(partial)
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The engine lost power during cruise flight, and the helicopter collided with high vegetation during an autorotative descent. Just before touchdown during the forced landing, engine power was restored; however, the pilot decided to concentrate on successfully completing the forced landing. The helicopter touched down in high vegetation and was substantially damaged. The power loss was not preceded by any auditory or visual warnings, and none occurred during the descent. Following recovery of the helicopter from the remote site, the engine was visually examined then placed into a test cell and run up. During the first engine run, the engine exhibited the following results: (1) normal start; (2) normal warm-up; (3) lean operation upon accelerating between 2,250 and 2,300 rpm with no fuel boost pump on; (4) upon turning on the test cell's fuel boost pump, the engine accelerated between 2,700 and 2,800 rpm with no hesitation. During the second engine run, with a carburetor from another Lycoming O-540 engine, the accident engine operated normally during run up to full power without the test cell's fuel boost pump turned on. Thereafter, the accident carburetor was examined, including a flow bench test, and no abnormalities were found that would have prevented the carburetor from functioning within prescribed design specifications. The reason for the excessively lean mixture/restricted fuel flow, which reduced the engine's available power, was not ascertained.
Probable cause
the partial loss of engine power due to an excessively lean mixture for undetermined reasons during cruise flight.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX03LA235
- Event ID
- 20030718X01148
- Case number
- LAX03LA235
- 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, coordinates. 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: efd1093dc69c10ff93efa93da1ecb59497149788eb9d11bbe9ce5af4ef3deee9; retrieved 2026-09-22T08:58:55.678Z.