SEA89FA186 · American AA-1A
American AA-1A · Accident: in flight encounter with weather
From Grant County International Airport (MWH) to King County International Airport - Boeing Field (BFI)
Event
- NTSB case
- SEA89FA186
- 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
- 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
American AA-1A
- Aircraft type
- American AA-1
- 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
- N9473L
- Operator
- The Aviators
- Onboard fatalities
- Unknown
- Route
- From Grant County International Airport (MWH), Moses Lake, WATo King County International Airport - Boeing Field (BFI), Seattle, 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
- Unknown
- 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
- In flight encounter with weather
- 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 › Flight into known adverse weather, attempted
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING A PERSONAL CROSS COUNTRY FLIGHT, THE AIRPLANE COLLIDED WITH TREES IN MOUNTAINOUS TERRAIN. A WEATHER BRIEFING OBTAINED EARLIER THAT DAY BY THE PILOT INCLUDED IN-FLIGHT PRECAUTIONS ALONG HIS ROUTE OF FLIGHT. STRONG UP AND DOWNDRAFTS IN THE MOUNTAINS ALONG WITH POSSIBLE RIME AND MIXED ICING CONDITIONS WERE MENTIONED. STRONG WINDS WERE PRESENT IN THE AFTERNOON AT THE ALTITUDES THE PILOT HAD REPORTED TO BE USING. THE PILOT DID NOT OBTAIN AN UPDATED BRIEFING FOR THE AFTERNOON CONDITIONS.
Probable cause
ATTEMPTED FLIGHT INTO KNOWN ADVERSE WEATHER CONDITIONS. FACTORS INCLUDE CLOUDS, DOWNDRAFTS, HIGH WINDS.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA89FA186
- Event ID
- 20001213X28201
- Case number
- SEA89FA186
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1989-04-07.
- API snapshot SHA-256: 57ef46bba585f3c26788f088fcf17795d1924249bd98a81736cf31430f70b925; retrieved 2026-09-21T03:21:16.714Z.