SEA03LA073 · Pilatus B4-PC11AF
Pilatus B4-PC11AF · Accident: on ground/water collision with object during landing
From Bergseth Field (WN76) to an unrecorded destination
Event
- NTSB case
- SEA03LA073
- 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
Pilatus B4-PC11AF
- Aircraft type
- Pilatus B4
- Category
- Glider
- 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
- N159AS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bergseth Field (WN76), Enumclaw, 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
- Landing · landing roll
- 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
- On ground/water collision with object
- 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
- Pilot in command › Directional control, not maintained
- Pilot in command › Wrong runway, selected
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The glider pilot departed under tow from runway 28 at the turf/dirt airstrip under winds reported as calm to 5 knots from the west. After encountering turbulence the pilot re-entered the pattern and set up for an approach and landing on runway 10. The aviation surface weather observations for a number of sites located north and west of the airstrip reported generally northwesterly winds ranging from 8 to 11 knots at the surface. The pilot rolled onto final in a 5 degree right angling approach which he attempted to correct with the application of left rudder and aileron just before touchdown. The glider did not respond and subsequently touched down with the nose angled about 10-15 degrees right of the centerline. The glider then rolled off the south side of the runway impacting trees. The pilot reported that there was no mechanical malfunction with the aircraft at the time of the event.
Probable cause
The pilot's failure to maintain directional control. Contributing factors were the crosswind/tailwind conditions and the trees which the glider impacted.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA03LA073
- Event ID
- 20030430X00598
- Case number
- SEA03LA073
- 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, 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: bd2ead3967968d17a282b8462ad1bf58162dad4532b59101d70d41cb612b731d; retrieved 2026-09-22T09:20:52.131Z.