WPR14LA263 · Knell ASC SPIRIT
Knell ASC SPIRIT · Accident: aerodynamic stall/spin on approach
From Cedar Valley Airport (UT10) to Cedar Valley Airport (UT10)
Event
- NTSB case
- WPR14LA263
- 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
- 1 · 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
Knell ASC SPIRIT
- Aircraft type
- Knell ASC SPIRIT
- 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
- N127JK
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Cedar Valley Airport (UT10), Lehi, UTTo Cedar Valley Airport (UT10), Lehi, UT
- Aircraft age
- About 7 years (built 2007)
- 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
- 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
- Aerodynamic stall/spin
- 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 private pilot of the experimental, amateur-built glider was conducting a local flight. The tow plane pilot reported that, as the glider pilot approached the privately owned airport, he announced over the radio his intent to land. He and one witness in the area reported seeing the glider circling to land and making several steep turns during the descent. When the glider was about 30 to 40 ft above ground level, the nose suddenly dropped, and the glider then descended straight down into the ground short of the runway. Another witness reported that it looked like the glider had stalled.
Wreckage documentation indicated that the glider impacted terrain in a steep, nose-down, left-wing-low attitude with little forward motion, which is consistent with a stall. Postaccident examination of the airframe revealed no anomalies that would have precluded normal operation. It is likely that the pilot exceeded the glider's critical angle of attack while maneuvering to land, which resulted in an aerodynamic stall.
Probable cause
The pilot’s exceedance of the glider’s critical angle of attack while maneuvering in a steep turn at low altitude, which resulted in an aerodynamic stall.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR14LA263
- Event ID
- 20140623X11029
- Case number
- WPR14LA263
- 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: 9db86176e962044b287c393e68dc3ce7cebb4ebac182ac5952af4f04be7084bd; retrieved 2026-09-14T17:20:22.316Z.