LAX96LA150 · Lampert REVOLUTION M500 REVOLUTION
Lampert REVOLUTION M500 REVOLUTION · Accident: airframe, component or system failure on approach
From Half Moon Bay Airport (HAF) to San Carlos Airport (SQL)
Event
- NTSB case
- LAX96LA150
- 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
Lampert REVOLUTION M500 REVOLUTION
- Aircraft type
- Lampert REVOLUTION M500
- 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
- N750GL
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Half Moon Bay Airport (HAF), Half Moon Bay, CATo San Carlos Airport (SQL)
- 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
- Approach · VFR pattern final
- 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
- Pilot in command › Autorotation, not performed
- Pilot in command › Unsafe/hazardous condition, not identified
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
According to FAA airman records, the pilot did not hold a rotorcraft category rating. FAA inspectors examined the pilot's logbook and reported that he received a solo endorsement in helicopters about 1 1/2 years ago. The pilot was returning to the airport following a local area flight. About 1 mile west of the airport, the pilot began to smell something burning and said he sensed something was wrong. Shortly thereafter, he heard a 'slap' sound as the helicopter transitioned through 50 feet and 50 knots about 1/4 mile from the runway. The pilot stated that he 'didn't do anything [with the controls] but keep it headed for an open area between the taxiway and the runway.' The pilot said he did not flare or touch the collective, and the helicopter hit hard in the open area and rolled on its left side. An FAA airworthiness inspector examined the helicopter and found the engine to transmission drive belt fragmented, with rubber transfer throughout the engine compartment. Rubber transfer on the pulleys showed a forward movement pattern of the belt off the pulley. The inspector reported that the pulley was designed without a flange or other means to keep the belt aligned.
Probable cause
the pilot's failure to recognize a drive train disengagement and initiate an autorotation. The inadequate engine-to-transmission drive belt/pulley design, and the pilot's limited training and experience in rotorcraft operations were factors in this accident.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX96LA150
- Event ID
- 20001208X05440
- Case number
- LAX96LA150
- 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: a07b10f39dc76f424c7995f6a7a4304b0fa7a642cda1e180b387e25f539e25c4; retrieved 2026-09-21T21:56:14.427Z.