SEA89LA150 · Schleicher ASW-20BL
Schleicher ASW-20BL · Accident: hard landing during an emergency descent
Event
- NTSB case
- SEA89LA150
- 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
- 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
Schleicher ASW-20BL
- Aircraft type
- Schleicher ASW-20
- 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
- N300Y
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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
- Emergency descent
- 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
- Hard landing
- 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
- Flight control, speed brake › Unlocked
- Pilot in command › Emergency procedure, not understood
- Pilot in command › Glider/tow release, premature
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING A LOCAL PLEASURE FLIGHT, WHILE STILL IN TOW, THE TOW PLT TRANSMITTED TO THE GLIDER. THE GLIDER PLT COULD NOT UNDERSTAND THE TRANSMISSION AND SHORTLY THEREAFTER NOTED THAT THE TOW PLANES RUDDER WAS WAGGING. THE GLIDER PLT THOUGHT THAT THE TOW PLT WANTED HIM TO RELEASE. THE GLIDER PLT RELEASED FROM THE TOW AT APRX 100' AGL WHICH RESULTED IN A HARD LANDING. LATER, THE GLIDER PLT WAS NOTIFIED THAT THE REASON FOR THE TRANSMISSION AND THE RUDDER WAG WAS THAT HE WAS BEING NOTIFIED THAT THE SPOILERS HAD DEPLOYED. THE PLT DID NOT CHECK DURING THE PREFLIGHT INSPECTION IF THE SPOILERS HAD BEEN LOCKED.
Probable cause
MISUNDERSTOOD EMERGENCY PROCEDURES, THE GLIDER PILOT RELEASED FROM THE TOW WHICH RESULTED IN A HARD LANDING. THE PILOT'S PREFLIGHT OF THE GLIDER AND RADIO COMMUNICATIONS WERE INADEQUATE BEFORE AND DURING THE FLIGHT.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA89LA150
- Event ID
- 20001213X29258
- Case number
- SEA89LA150
- 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: b86dbfdec309fa70ab28d3db11d86eb910eab38fad10673a133c5c465e308968; retrieved 2026-09-23T07:15:49.158Z.