WPR11LA183 · Tomei S12 XL
Tomei S12 XL · Accident: loss of control in flight during takeoff
From Pleasant Grove, CA (private airstrip) to Pleasant Grove, CA (private airstrip)
Event
- NTSB case
- WPR11LA183
- 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
- Instrument Meteorological Cond
Tomei S12 XL
- Aircraft type
- Tomei S12
- 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
- N8113N
- Operator
- Tomei Ed J
- Onboard fatalities
- Unknown
- Route
- From Pleasant Grove, CA (private airstrip)To Pleasant Grove, CA (private airstrip)
- 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
- Takeoff
- 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
- Loss of control in flight
- 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
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
A pilot-rated witness said that the airplane was airborne within “a couple of minutes” after the engine was started and that, when the airplane reached an altitude of 200 to 300 feet above the ground during climb out, it appeared to slow. The witness said that the airplane then banked left and descended in a spiral until it impacted the ground. Postaccident examination of the engine revealed evidence of abnormal piston wear and cylinder damage, including mechanical scoring and vertical grooves along the forward cylinder walls and piston skirt. A representative of the engine manufacturer reported that the observed cylinder and piston damage was consistent with an in-flight cold seizure of the piston (a condition where the piston seizes within the cylinder). About 17 years before the accident, the engine manufacturer issued a Service Information Letter (SIL) that addressed the potential for such a piston seizure. The SIL stated in part “...Putting a cold engine to hard work without uniform and correct warm up will cause the piston to expand quicker than the cylinder, minimizing clearance and creating piston scuffing and seizure.” It is likely that the pilot did not allow enough time for the engine to warm up before taking off.
Probable cause
The pilot’s failure to allow the airplane’s engine to properly warm up before applying takeoff power, which resulted in the forward cylinder's piston seizing and a subsequent loss of engine power. Also causal was the pilot's failure to maintain an adequate airspeed after the loss of engine power, which resulted in a stall-spin.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR11LA183
- Event ID
- 20110403X10730
- Case number
- WPR11LA183
- 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: 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: 481dc0668fa3717a3c8b0af11bbb0c462a10aadc97ab001a6bc8742ab8b89da2; retrieved 2026-09-13T21:19:03.374Z.