SEA86FA165 · Thorp T-18
Thorp T-18 · Accident: loss of control in flight on approach
From Sunriver Airport (S21) to Richland Airport (RLD)
Event
- NTSB case
- SEA86FA165
- 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
- 2 · all aircraft and ground
- Ground fatalities
- 0
- 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
- N2056
- Operator
- Donald A. Mccune · private individual
- Onboard fatalities
- Unknown
- Route
- From Sunriver Airport (S21), SUN RIVER, ORTo Richland Airport (RLD), Richland, 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
- Approach · VFR pattern base
- First occurrenceThe 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
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- 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
- Destroyed
Cause areas
- Pilot in command › Airspeed, not maintained
- Pilot in command › Remedial action, excessive
- Pilot in command › Stall/spin, inadvertent
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AT TIME OF MISHAP, ACFT PRESUMED TO BE IN RT-HAND APPROACH TO LAND IN 20-KT, 40 DEGREE RT CROSSWIND. WITNESSES FIRST OBSERVED ACFT DESCENDING VERTICALLY, OUT OF CONTROL, IN AN AREA CONSISTENT WITH THE 90 DEGREE APPROACH POSITION. EVIDENCE INDICATES ACFT CONTACTED SOFT, SANDY TERRAIN IN VERTICAL ATTITUDE, THEN FELL OVER TO UPRIGHT FLAT ATTITUDE BEFORE INTENSE POST-IMPACT FIRE INCINERATED MOST OF AIRFRAME. NO EVIDENCE FOUND OF MECHANICAL FAILURE/MALFUNCTION. SCENARIO INDICATIVE OF STEEP TURN TO CORRECT CROSSWIND-INDUCED CLOSE-IN PATTERN.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record SEA86FA165
- Event ID
- 20001213X34319
- Case number
- SEA86FA165
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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. 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: 5131d0ef701c9f57fb1aa61cedca1e5ca93ee977c8f9d64309a61c9ecd68e8ac; retrieved 2026-09-21T04:29:47.640Z.