WPR09LA130 · Toland S/Thornburgh J TWIN 503SL
Toland S/Thornburgh J TWIN 503SL · Accident while standing
From Zamperini Field (TOA) to Zamperini Field (TOA)
Event
- NTSB case
- WPR09LA130
- 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
Toland S/Thornburgh J TWIN 503SL
- Aircraft type
- Toland S/thornburgh TWIN 503
- Category
- Weight-Shift
- 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
- N426MT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Zamperini Field (TOA), Torrance, CATo Zamperini Field (TOA), Torrance, CA
- 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
- Standing · engine(s) operating
- 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
- Miscellaneous/other
- 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
- Aircraft › Aircraft power plant
- Personnel issues › Action/decision
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The owner/pilot said that the pilot-rated passenger, who was seated in the front seat, had been shown the function of the steering bar, the pedals, the brake, and the throttle. After engine start and while performing the pre-taxi checklist, the steering control bar was tied to the glider's frame tube with a bungee cord. The pilot performed a brake check from the rear seat and then asked the passenger to perform the brake check from the front seat. The glider foot controls are similar to airplane controls, except when the top of the left pedal is depressed it activates the nosewheel brake. When the top of the right pedal is depressed it activates the throttle instead of activating the brake. After the pilot asked the passenger to perform the brake check, the glider engine accelerated to full power and the glider became airborne. Because the control bar was tied to the main frame of the glider the pilot was unable to attain control before the glider stalled. The owner/pilot indicated that the glider did not have a mechanical malfunction or failure.
Probable cause
The passenger’s inadvertent activation of the engine throttle.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR09LA130
- Event ID
- 20090227X25653
- Case number
- WPR09LA130
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2009-02-27.
- API snapshot SHA-256: b33f247de6bb6bc8a90099c906ebc2923b70329a0dd71ef58c2c39dac1954a72; retrieved 2026-09-13T19:58:04.442Z.