LAX95LA106 · Burkhart Grob TWIN ASTIR
Burkhart Grob TWIN ASTIR · Accident: in flight collision with object on approach
From Sierra Vista Municipal Airport / Libby Army Air Field (FHU) to an unrecorded destination
Event
- NTSB case
- LAX95LA106
- 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
Burkhart Grob TWIN ASTIR
- Aircraft type
- Grob TWIN ASTIR
- 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
- N333BH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sierra Vista Municipal Airport / Libby Army Air Field (FHU), AZTo 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
- Approach · VFR pattern final
- 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 collision with object
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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 › Clearance, not maintained
- Pilot in command › In-flight planning/decision, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AFTER THE TOW RELEASE, THE GLIDER PILOT HAD DIFFICULTY LOCATING THERMALS FOR LIFT. HE SAW A FIELD AND PROCEEDED TO MANEUVER FOR AN OFF-AIRPORT LANDING. DURING THE APPROACH PHASE, HE SAW POWER LINES PERPENDICULAR TO THE INTENDED LANDING DIRECTION, SO HE MANEUVERED TO LAND PARALLEL TO THE POWER LINES. AS HE CONTINUED THE APPROACH, WHICH WAS OVER THE LEE SIDE OF SOME HILLS, THE GLIDER ENCOUNTERED AN INCREASE IN SINK RATE AND A DECREASE IN AIRSPEED. THE PILOT ATTEMPTED TO GAIN ENERGY AND TO CLEAR OBSTACLES; HOWEVER, THE LEFT WINGTIP COLLIDED WITH A TREE AND THE GLIDER CRASH LANDED.
Probable cause
IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, WHICH RESULTED IN HIS FAILURE TO REMAIN CLEAR OF TREE(S) DURING AN OFF-AIRPORT LANDING. FACTORS RELATED TO THE ACCIDENT WERE: LACK OF THERMAL LIFT, AND HIGH OBSTRUCTIONS IN THE OFF-AIRPORT LANDING AREA.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX95LA106
- Event ID
- 20001207X02991
- Case number
- LAX95LA106
- 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: 5d79d6fb8bc2107748ec85676c96936833054ecccf3485f73e9bdef5ed0185f5; retrieved 2026-09-23T00:15:50.260Z.