Amateur-built TWIN 503SL accident near Torrance, California, February 27, 2009
On February 27, 2009 at about 5:00 am local time, a amateur-built TWIN 503SL (weight-shift aircraft), registered N426MT, was substantially damaged in an accident during standing (engine(s) operating) near Torrance, California (Zamperini Field Airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The passenger’s inadvertent activation of the engine throttle.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 27, 2009 · about 5:00 am local time
- Place
- Torrance, California · Zamperini Field Airport · map
- Type
- Accident
- Injuries
- 1 person was killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built TWIN 503SL
- Registration
- N426MT · no longer on the register · serial 95
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Miscellaneous/other during standing (engine(s) operating) defining event
- Loss of control in flight during takeoff
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Passenger
- cause Aircraft › Aircraft power plant › Engine controls › Power lever › Unintentional use/operation
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › (general) › Attain/maintain not possible
Pilot
- Certificate: airline transport pilot, commercial pilot, private
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: glider; instructor: gyroplane; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instructor: sport pilot; instrument: airplane; instrument: helicopter; rotorcraft: balloon; rotorcraft: glider; rotorcraft: gyroplane; rotorcraft: helicopter
- Flight time: 17,000 hours in all; 300 in this make and model; 70 in the last 90 days; 20 in the last 30 days; 10,000 as pilot in command; 5,000 on instruments
- Last flight review: June 8, 2007
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rear
- Injury: serious injuries
Crew member
- Certificate: private
- Ratings: single-engine land
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: frt
- Injury: fatal
The aircraft
- Airframe total time: 318 hours
- Last inspection: annual inspection, February 21, 2009; 2 hours since
- Maximum gross weight: 880 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotax 503 (piston); 0 hours total
The flight
- Departed from: TOA Torrance CA at 5:00 am
- Destination: TOA Torrance CA
- Flight plan: not recorded
- A second pilot was aboard
Weather at the time
- Light: night
- Wind: from 220° at 4 knots
- Visibility: 10 statute miles
- Sky: overcast at 1,600 ft
- Temperature: 57°F (14°C), dew point 52°F (11°C)
- Altimeter: 30.12 inHg
- Observation at 4:53 am from HHR, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.