Schweizer SGS123 accident near Tunbridge, Vermont, May 13, 2018
On May 13, 2018 at about 7:36 pm local time, a 1966 Schweizer SGS123 (glider), registered N9915J, was substantially damaged in an accident during enroute near Tunbridge, Vermont. It was a personal 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 student glider’s inability to maintain altitude due to a loss of thermal lift, which resulted in an off-airport landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 13, 2018 · about 7:36 pm local time
- Place
- Tunbridge, Vermont · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schweizer SGS123 H15, built 1966
- Registration
- N9915J · no longer on the register · serial 71
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The solo student glider pilot reported that, during the return flight to the airport, he was unable to maintain enough lift and did not have enough altitude to cross a section of forest between his location and the airport. After he selected a field for landing, during the base leg turn, he determined that he did not have enough altitude to clear a line of trees at the threshold of the field. He then continued straight ahead, parallel to the line of trees, and impacted the ground in a small clearing. The glider sustained substantial damage to the left wing and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the glider that would have precluded normal operation.
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
- Loss of lift during enroute defining event
- Off-field or emergency landing during landing
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › Thermal lifting › Effect on operation
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Attain/maintain not possible
Pilot
- Certificate: student
- Flight time: 114 hours in all; 5 in the last 90 days; 5 in the last 30 days
- Medical certificate: None
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 1,035 hours
- Last inspection: annual inspection, June 22, 2017
- Maximum gross weight: 750 lb
- Seats: 1
- Landing gear: fixed
- Engine: (none); 0 hours total
- Operator: Post Mills Soaring Club INC
The flight
- Departed from: 2B9 Post Mills VT at 5:59 pm
- Destination: 2B9 Post Mills VT
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 190° at 9 knots, gusting 18
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 36°F (2°C)
- Altimeter: 30.02 inHg
- Observation at 7:53 pm from KLEB, 17 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on August 2, 2018. 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/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Accident Picture | PDF, 1 page | 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.