SEA08LA207 · Simpson Amphibious Trike
Simpson Amphibious Trike · Accident: aerodynamic stall/spin during initial climb
From Lake Chelan Airport (S10) to Lake Chelan Airport (S10)
Event
- NTSB case
- SEA08LA207
- 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
- 0 · 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
Simpson Amphibious Trike
- Aircraft type
- Simpson AMPHIBIOUS TRIKE
- 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
- N440LS
- Operator
- Laurence R Simpson · private individual
- Onboard fatalities
- Unknown
- Route
- From Lake Chelan Airport (S10), Chelan, WATo Lake Chelan Airport (S10), Chelan, WA
- 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
- Aerodynamic stall/spin
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot had transported the float-equipped weight-shift amateur-built airplane to the training facility for assistance in having it certified, as well as to receive flight instruction in the airplane. When the flight instructor informed the pilot that his flight training would be postponed for about two weeks, the pilot agreed to wait. The flight instructor cautioned the pilot not to attempt to fly the airplane until he had received adequate training, to which the pilot agreed. Subsequently, the pilot elected to fly the airplane without having received any flight instruction. During the takeoff, witnesses reported observing the airplane climb rapidly, followed by a left wing low, steep nose down attitude prior to impacting the ground with its left wing, consistent with a stall/spin. According to the flight instructor, the airplane's 19-meter wing, known for its lifting capacity, most probably caused the inexperienced pilot to think that he was airborne, when the airplane was only light on its wheels, resulting in the pilot pushing out on the control bar thinking he would climb out. However, not having enough airspeed to sustain flight, the wing stalled. No pre-impact anomalies were reported with the airplane.
Probable cause
The pilot's failure to maintain adequate airspeed during the initial climb, which resulted in an inadvertent aerodynamic stall. Contributing to the accident was the pilot's lack of experience in the float-equipped, weight-shift airplane.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA08LA207
- Event ID
- 20081017X44942
- Case number
- SEA08LA207
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- 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. 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: 3200763f5a1a1cda6ef61a2cc37ea0d7c5f5e06a6a1a01ccc154c3879d6cb0f1; retrieved 2026-09-15T10:28:43.879Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: destination. The city field holds the airport name; S10 is Lake Chelan Airport at Chelan, WA, as the departure field for the same identifier records.