CEN09CA368 · Grob G103 TWIN II
Grob G103 TWIN II · Accident: loss of control in flight during takeoff
From Owl Canyon Gliderport (4CO2) to Owl Canyon Gliderport (4CO2)
Event
- NTSB case
- CEN09CA368
- 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
Grob G103 TWIN II
- Aircraft type
- Grob G103
- 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
- N5462N
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Owl Canyon Gliderport (4CO2), Wellington, COTo Owl Canyon Gliderport (4CO2), Wellington, CO
- 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
- Takeoff
- Defining eventThe 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
- Loss of control in flight
- 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
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported that the initial takeoff roll was normal, but that after a premature takeoff due to wind gusts and thermals the glider controls became ineffective. The pilot attempted to pull the tow line release knob and reported that the tow line “back-released,” resulting in the glider entering a stall. During the impact with terrain, the glider's empennage separated partially, just aft of the fuselage. Examination of the tow line release mechanism and glider systems revealed no mechanical anomalies.
Probable cause
The pilot’s failure to maintain control of the glider during takeoff.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN09CA368
- Event ID
- 20090621X30522
- Case number
- CEN09CA368
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: f076b776d436091a7e7ac29745a5a6735e48d017f47e38c93dd6ccb029b27d65; retrieved 2026-09-15T11:30:40.324Z.