SEA08CA172 · Lyons Navajo HKS
Lyons Navajo HKS · Accident: turbulence encounter while maneuvering
From Lake Chelan Airport (S10) to an unrecorded destination
Event
- NTSB case
- SEA08CA172
- 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
Lyons Navajo HKS
- Aircraft type
- Lyons NAVAJO HKS
- 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
- N1762C
- Operator
- John Winkenwader
- Onboard fatalities
- Unknown
- Route
- From Lake Chelan Airport (S10), Chelan, 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
- Maneuvering
- 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
- Turbulence encounter
- 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
- 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
The sport pilot flight instructor reported that while maneuvering during a local instructional flight, he noticed dust forming in a circular pattern in the air near their position. The student pilot, who was flying the airplane, initiated a climbing 180-degree turn towards their point of departure. While approaching a ridge line about 800 feet above ground level, the instructor noted the turbulence was increasing, and when the airplane started to descend, he took the controls. The instructor stated that despite using full throttle, the airplane continued to descend rapidly while "getting forced down by a microburst," prompting him to initiate a forced landing in an open field. The instructor added that due to the low altitude, he was unable to align the airplane with the rows of dirt. During the approach to landing, the airplane "caught some lift" and subsequently entered a "strong down draft" and impacted the ground. Examination of the airplane by the instructor revealed that both wings and fuselage framing were structurally damaged. The instructor stated that there were no mechanical anomalies with the engine or flight control system that would have prevented normal operation.
Probable cause
The pilot's failure to maintain aircraft control while maneuvering. Contributing to the accident was a microburst condition.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA08CA172
- Event ID
- 20080828X01349
- Case number
- SEA08CA172
- 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: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2008-08-07.
- API snapshot SHA-256: fe6955a7b9500ca93597a0cfa08f1e1ab4a5c4434ce3db242ed295521339b29f; retrieved 2026-09-15T10:07:42.424Z.