LAX04LA106 · Cox Thorpe T-18
Cox Thorpe T-18 · Accident: vortex turbulence encountered during landing
From Compton Woodley Airport (CPM) to an unrecorded destination
Event
- NTSB case
- LAX04LA106
- 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
- 1 · 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
Cox Thorpe T-18
- Aircraft type
- Cox Thorpe T-18
- Category
- Airplane
- 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
- N64EC
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Compton Woodley Airport (CPM), Compton, CATo 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
- Landing · flare/touchdown
- 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
- Vortex turbulence encountered
- 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 › Visual lookout, inadequate
- Pilot of other aircraft › Visual lookout, inadequate
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
After encountering downwash induced wake vortices from a helicopter, the airplane rolled over and impacted terrain while on short final approach. The pilot of the airplane was performing practice touch-and-go takeoffs and landings at the airport and made a radio transmission stating his intentions. A police helicopter pilot was on a 2-mile straight in approach for the same runway, and made a radio transmission stating his intentions. While on final approach for the runway, with the airplane pilot beginning a flare about 8 feet above ground level, the police helicopter's pilot was attempting a practice autorotation and descended in front of the airplane. At the last moment, the airplane's pilot saw the helicopter and made an abrupt turn to the right in an attempt to execute a go-around. The airplane rolled over inverted and impacted terrain. The helicopter pilot stated he never saw the airplane or heard the pilot's radio transmissions. Federal Aviation Regulations state that "when two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right of way, but it shall not take advantage of this rule to cut in front of another which is on final approach to land, or to overtake that aircraft." (14 CFR 91.113)
Probable cause
both pilots' failure to see and avoid one another that resulted in the airplane's encounter with downwash induced wake vortices from the helicopter, and the airplane pilot's subsequent loss of control.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX04LA106
- Event ID
- 20040203X00154
- Case number
- LAX04LA106
- 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: 258823d8cb0d01c03db7c7d95404dc6435d3f6fcd8069716167e41072f41844f; retrieved 2026-09-20T18:36:12.862Z.