Grob G103 accident near San Antonio, Texas, August 22, 2019
On August 22, 2019 at about 8:45 pm local time, a 1981 Grob G103 (glider), registered N901BG, was substantially damaged in an accident during initial climb near San Antonio, Texas (Boerne Stage Field). It was a glider-towing flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the glider tow rope, which lodged in the glider's rudder and resulted in a hard landing. Contributing to the accident was the pilot's failure to properly secure the glider's aft canopy.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 22, 2019 · about 8:45 pm local time
- Place
- San Antonio, Texas · Boerne Stage Field · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Grob G103 TWIN II, built 1981
- Registration
- N901BG · registry record · serial 3648
- Damage
- Substantial damage
- Flight
- Glider-towing flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The glider pilot reported that, while being towed and approaching 3,000 ft above ground level, the glider's rear canopy opened. The glider pilot informed the tow airplane pilot via radio that the canopy had opened, and the tow airplane pilot informed the glider pilot that he would try to tow the glider closer to the runway. Shortly after, the glider entered an uncontrollable downward spin, and the front canopy shattered. The pilot regained control of the glider, and the rear canopy separated from the glider. The glider pilot made an extended right base and prepared for an off-airport landing. The flight controls were not responding properly, and the glider landed hard on the runway. The pilot reported that, after the accident, he found a section of the tow rope still connected to the glider and lodged in the rudder mechanism. A review of photographs of the airplane revealed that the tow rope exhibited overload signatures. Each airplane still had a portion of the tow rope attached to it after the tow rope failed. The glider sustained substantial damage to the composite fuselage.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Glider tow event during initial climb defining event
- Loss of control in flight during initial climb
- Altitude deviation during initial climb
- Hard landing during landing
The NTSB's findings
- cause Aircraft › Aircraft structures › Fuselage › Aerial tow equipment section › Failure
- cause Aircraft › Aircraft systems › Equipment/furnishings › (general) › Failure
- factor Personnel issues › Task performance › Use of equip/info › Use of equip/system › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 0 hours in all; 0 in this make and model
- Medical certificate: Unknown
- Injury: no injuries
The aircraft
- Seats: 1
- Landing gear: retractable
- Operator: San Antonio Soaring Society Inc
The flight
- Departed from: 5C1 San Antonio TX
- Destination: 5C1 San Antonio TX
- Flight plan: none
- Runway 17, 5,006 ft by 60 ft
Weather at the time
- Light: daylight
- Wind: from 150° at 4 knots
- Visibility: 10 statute miles
- Sky: scat at 7,000 ft
- Temperature: 91°F (33°C), dew point 64°F (18°C)
- Altimeter: 29.92 inHg
- Observation at 8:35 pm from KSAT, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on January 23, 2020. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot's Statement | PDF, 1 page | View Download |
| 2 | Memorandum for Record – Pilot | PDF, 1 page | View Download |
| 3 | Photo | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.