WPR14LA367 · Piper PA 25-235
Sky Sailing Piper PA 25-235 · Accident: glider tow event en route
From Warner Springs Gliderport Airport (CL35) to Warner Springs Gliderport Airport (CL35)
Event
- NTSB case
- WPR14LA367
- 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
Piper PA 25-235
- Aircraft type
- Piper PA-25
- Category
- Airplane
- 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
- N7117Z
- Operator
- Sky Sailing
- Onboard fatalities
- Unknown
- Route
- From Warner Springs Gliderport Airport (CL35), Warner Springs, CATo Warner Springs Gliderport Airport (CL35), Warner Springs, CA
- Aircraft age
- About 50 years (built 1964)
- 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
- En route · climb to cruise
- 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
- Glider tow event
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot of the tow plane had already launched a series of gliders without incident just before the accident. Downwind departure operations were in effect due to wind conditions and the local topography; the glider pilot had been briefed on the departure procedures earlier in the day and had experience flying the departure. For the accident flight, the glider was moved into position, and the glider pilot indicated his intentions via hand signals.
Shortly after takeoff, the glider moved out of position. The glider pilot made corrective control inputs as the flight progressed in the traffic pattern; however, he was unable to establish positive control. The glider violently yanked and pulled the tow plane into unusual attitudes throughout the departure, and a positive rate of climb could not be established. The glider pilot continued to encounter control difficulties consistent with pilot-induced oscillations, and the tow line became slack as the glider gained on the tow plane. The tow plane pilot thought the glider had released, and a few seconds later, as the line went taught, the tow plane was forced into an aerodynamic stall. Both pilots simultaneously released the tow line, and, with minimal altitude remaining for recovery, the tow plane crashed in a field just beyond the runway. The glider returned to the airport and landed without incident.
Probable cause
The glider pilot's failure to maintain directional control during the initial climb while being towed, which led to the tow plane's unstable flight and its subsequent aerodynamic stall. Contributing to the accident was the tow pilot's delayed release of the glider.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR14LA367
- Event ID
- 20140906X80358
- Case number
- WPR14LA367
- 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. 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: e3e963d4446b3a6804d28cc199b7f647e475488d98e2cb7f9f668a9754c64e63; retrieved 2026-09-16T01:43:46.313Z.