SEA08LA127 · Thorp T-18
Thorp T-18 · Accident: loss of engine power (total) during initial climb
From Norman Grier Field (S36) to an unrecorded destination
Event
- NTSB case
- SEA08LA127
- 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
Thorp T-18
- Aircraft type
- Thorp 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
- N8613A
- Operator
- Roger Thompson
- Onboard fatalities
- Unknown
- Route
- From Norman Grier Field (S36), Kent, WATo 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
- Initial climb
- 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 engine power (total)
- 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
- Not determined › Not determined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot had recently installed an overhauled carburetor and new air inlet on the airplane. Because the airplane had not been flown for about nine months, the pilot drained all of the old fuel out of the airplane and refueled it. Witnesses reported that the pilot performed an extensive engine run up that lasted 10 to 15 minutes, and with satisfactory results, the pilot decided to take the airplane around the airport traffic pattern. A witness based at the airport said that during the initial takeoff, the engine sound was smooth. As it continued, the witness heard the engine running rough. When the airplane flew past the witness about 300 feet above the runway, the witness saw two puffs of white smoke. The airplane appeared to have adequate airspeed and it was still climbing, although the engine was cutting out. The engine then cut out completely and the airplane continued straight ahead for about 1 second. The airplane entered a slow turn to the right, and when it had turned approximately 160 degrees, the right wing stalled and the airplane rolled into a spin. The airplane went out of view of the witness in a nose-down attitude of approximately 70 degrees. A friend of the pilot who was based at the airport said that when departing to the north as the pilot had done, there are limited options available for emergency landings. The fuel valve was found in the closed, or "off", position. Based on the length of the engine run up, the fuel selector was undoubtedly positioned correctly at takeoff and was most likely moved to the closed position by the pilot when he determined that a forced landing was inevitable. Post accident examination of the wreckage did not disclose any pre-impact mechanical anomalies. Due to damage sustained to the carburetor, no functional testing could be performed.
Probable cause
The loss of engine power for undetermined reasons. Contributing to the accident were the lack of a suitable landing area and the pilot's failure to maintain an adequate airspeed while maneuvering in response to the loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA08LA127
- Event ID
- 20080515X00672
- Case number
- SEA08LA127
- 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: 86b366f77191f58ae868bc242c50ce1fedb34631a5e82024a1fc4807bf9effb8; retrieved 2026-09-13T19:04:25.335Z.