ERA09CA479 · Jonker JS-1B
Jonker JS-1B · Accident: collision during takeoff/landing
From Tullahoma Regional Airport William Northern Field (THA) to Tullahoma Regional Airport William Northern Field (THA)
Event
- NTSB case
- ERA09CA479
- 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
Jonker JS-1B
- Aircraft type
- Jonker JS-1
- 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
- N504BT
- Operator
- Barton L. Tate · private individual
- Onboard fatalities
- Unknown
- Route
- From Tullahoma Regional Airport William Northern Field (THA), Tullahoma, TNTo Tullahoma Regional Airport William Northern Field (THA), Tullahoma, TN
- 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
- Landing
- 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
- Collision during takeoff/landing
- 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 as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot had completed his first flight in his newly purchased glider earlier in the day. He stated that the flight lasted about 2.3 hours and was "an absolute pleasure." A witness familiar with the make and model of the accident glider had flown alongside the accident pilot in an identical glider during the flight, and stated that the accident pilot's takeoff, flight, and landing were "textbook examples." During the second flight of the day, the accident pilot was towed to 1,000 feet above ground level for the purpose of making a traffic pattern flight with a subsequent landing. The pilot stated that the downwind leg of the traffic pattern turning to the base leg was "high." The pilot applied full flaps, and stated that on the final leg of the traffic pattern, his sight picture was "still high," and the runway was "easily made." The pilot's sight picture then "quickly" changed to "short of the runway," and he realized he would not clear the trees prior to the runway. The pilot pitched up to avoid the trees, and after clearing them, "unloaded the wings" and "dived" into a parking lot. The glider impacted the parking lot and came to rest after the left wing impacted a tree. The glider sustained substantial damage to the left wing and vertical stabilizer. Neither the pilot nor a Federal Aviation Administration inspector, who examined the glider after the accident, reported any mechanical malfunctions or anomalies. Several witnesses on the ground reported a noticeable subsidence of wind while the glider was on the final leg of the traffic pattern. The nearest weather reporting station, located approximately 50 miles northwest of the accident site, reported winds from 320 degrees at 10 knots at the time of the accident.
Probable cause
The pilot's failure to maintain a proper glidepath while on approach, resulting in landing short of the runway.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA09CA479
- Event ID
- 20090825X21124
- Case number
- ERA09CA479
- 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: 2e491a16fe2045eb958463555794f540f628d4bec71b1846aa0cb9a0a43bf9fa; retrieved 2026-09-15T12:50:25.898Z.