FTW01FA129 · Cessna 150
Cessna 150 and Schleicher Ka-6E · Accident: loss of control in flight during initial climb
Event
- NTSB case
- FTW01FA129
- 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
Aircraft 1 · Cessna 150
- Aircraft type
- Cessna 150
- 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
- N5617E
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From H71H · Pryor, OKTo H71
- 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
- Initial climb
- 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
- 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
- Destroyed
Aircraft 2 · Schleicher Ka-6E
- Aircraft type
- Schleicher KA-6
- 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
- N9915X
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Mid America Industrial Airport (H71), Pryor, OKTo H71
- 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
- Initial climb
- 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
- Abrupt maneuver
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Pilot in command › Aircraft control, not maintained
- Pilot in command › Glider/tow release, delayed
- Pilot of other aircraft › Aircraft control, not maintained
- Pilot of other aircraft › Glider/tow release, delayed
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The glider pilot reported that during takeoff, he had to maintain a crab of 15 degrees into the wind in order to track down the runway centerline. Shortly after lift-off, the glider gained altitude abruptly and ascended to an altitude above the tow airplane. The glider pilot reported that he had encountered "severe turbulence" and was caught in an "extreme updraft." He remembered looking up at the sky, losing sight of the tow airplane, and being "jarred about the cockpit" while attempting to disengage the towrope. He recalled that his altimeter was indicating 440 feet agl approximately midway down the runway at the time he released the towrope, and he estimated the tow airplane to be 150 feet lower than his glider. The glider completed a normal traffic pattern and landed on the runway. The glider pilot mentioned that his glider had a tendency for the trim lever to release from its "full nose down" trim position, which is the recommended takeoff trim lever position, and "snatch" back to the "full nose up" position. He remembered having to push forward during the initial climb to counteract a nose up effect. A witness observed the glider gain altitude "relatively abrupt" and was able to detect that the glider was "decidedly higher" than the tow airplane. He saw the glider break away to the east and thought the problem was over. He continued to observe the tow airplane and stated that from his position the airplane appeared to level off momentarily, and then "nose dived and impacted the ground." A pilot, whose tow flight had departed just prior to the accident, reported that the wind was approximately 9 knots, and he did not experience any turbulence or gusty wind conditions. A functional check of the glider's trim operation was completed by placing the trim lever in the full nose down position (takeoff position) and then hand-tightened the wing nut, which is used to lock the lever in place. The control stick was then pulled aft, and the trim lever would release almost immediately. This procedure was repeated several times with the same result. The airplane's tow hook was found partially separated from the tail. Examination of the towrope revealed that the breakable link was broken.
Probable cause
the failure of the glider pilot to maintain aircraft control and his delay in releasing the towrope. A contributing factor was the glider's worn elevator trim friction, which resulted in its disengagement.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW01FA129
- Event ID
- 20010531X01040
- Case number
- FTW01FA129
- 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, damage. 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: 09925ec43e83f90ccd9aa437ee27a60824007c93878eaffb7fe21da111fda6f8; retrieved 2026-09-20T20:32:12.620Z.