SEA02LA140 · Blanik L-13
Blanik L-13 · Accident: on ground/water collision with terrain/water during landing
From Bozeman Yellowstone International Airport (BZN) to Bozeman Yellowstone International Airport (BZN)
Event
- NTSB case
- SEA02LA140
- 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
Blanik L-13
- Aircraft type
- Blanik L-13
- 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
- N70741
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bozeman Yellowstone International Airport (BZN), Belgrade, MTTo Bozeman Yellowstone International Airport (BZN), MT
- 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 terrain/water
- 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 › In-flight planning/decision, improper
- Pilot in command › Proper touchdown point, not obtained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
Just about the time the glider pilot was ready to initiate his base turn for the parallel sod runway, the tower controller asked him if he saw the traffic on a one mile final to the paved runway. According to the pilot, he then let go of the spoiler handle (the spoilers were partially deployed), in order to reach the microphone that was stored in a pocket on the right side of the glider. He advised the tower that he did not have the traffic in sight, put the microphone back in the pocket, and then reached back for the spoiler handle. At that time he discovered that the spoilers had deployed to the full open position. The pilot then immediately retracted the spoilers and made a turn to final. After turning final, the pilot realized that he probably would not be able to make it to the threshold of the sod runway, but because of the aircraft on final for the paved runway, he made the decision not to request a change to that runway (the threshold of which was approximately 2,500 feet closer to his position at the time). As the pilot continued on toward the threshold of the sod runway, he attempted to maneuver toward its right side in order to avoid some stakes that were between him and the runway threshold, and in order to land well clear of the paved runway. Ultimately the aircraft touched down approximately 200 feet short of the sod runway threshold and 50 feet to the right of its right edge. Although the initial touchdown in the tall weeds was uneventful, almost immediately after starting the landing roll, the aircraft impacted a ditch that the pilot had not been aware of.
Probable cause
The glider pilot's improper in-flight planning decision and his failure to attain the proper touchdown point. Contributing to the accident were the inadvertent activation of the speed brakes, the pilot's failure to maintain altitude, the high vegetation and the ditch.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA02LA140
- Event ID
- 20020812X01367
- Case number
- SEA02LA140
- 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: cceb5fadaf994e31a07f2e4f533adf18eb6ed2ad09eda732252c5bdb7447896a; retrieved 2026-09-21T19:39:24.339Z.