ERA18FA238 · Schweizer SGS 2 32
Schweizer SGS 2 32 · Accident: aerodynamic stall/spin while maneuvering
From Morrisville-Stowe State Airport (MVL) to Morrisville-Stowe State Airport (MVL)
Event
- NTSB case
- ERA18FA238
- 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
- 3 · 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
Schweizer SGS 2 32
- Aircraft type
- Schweizer SGS-2
- 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
- N17970
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Morrisville-Stowe State Airport (MVL), Morrisville, VTTo Morrisville-Stowe State Airport (MVL), Morrisville, VT
- Aircraft age
- About 45 years (built 1973)
- 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
- Maneuvering
- 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
- Aerodynamic stall/spin
- 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 commercial pilot of the glider departed on a 30-minute local sightseeing flight with two passengers seated in the rear seat. The pilot of the tow plane reported that during the tow to the glider's 4,500-ft mean sea level (msl) release altitude, he had to "weave around the clouds" and stated that the mountaintops were obscured by clouds. A witness who saw the glider release from tow stated that, following release, the glider flew away and "disappeared" into clouds. When the glider did not return as expected, the tow pilot initiated an aerial search; the glider was subsequently located in trees at an elevation of 3,673 ft msl about 7 miles west of the departure airport. The glider impacted terrain in a near-vertical, nose-down attitude; the forward cockpit was crushed, but the rear cockpit was largely intact. Examination of the glider revealed no evidence of preimpact mechanical malfunctions or anomalies that would have precluded normal operation.
The relatively low-energy, vertical impact attitude of the glider was consistent with an aerodynamic stall/spin. Weight and balance calculations revealed that the glider was likely about 50 lbs over its maximum gross weight at the time of the accident, but remained within its published center of gravity limits. The glider's increased gross weight would have resulted in an increased stall speed. Given the low clouds in the area, it is possible that the pilot inadvertently entered an area of reduced visibility and subsequently exceeded the glider's critical angle of attack, resulting in an aerodynamic stall and spin. It is also likely that the glider's increased gross weight and stall speed increased the glider's susceptibility to a stall/spin situation.
Although lap belts and shoulder harnesses were required for each occupant of the glider, the accident glider was equipped with only a single lap restraint for the front pilot's seat, and a single lap restraint for both rear seat occupants. The combined weight of the rear seat occupants likely resulted in the failure of the single lap belt's mounting hardware in overload.
Probable cause
The pilot's exceedance of the glider's critical angle of attack while maneuvering, which resulted in an aerodynamic stall/spin and impact with terrain. Contributing to the accident was the pilot's decision to operate the glider outside of its published weight limitations.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA18FA238
- Event ID
- 20180831X03709
- Case number
- ERA18FA238
- 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: ab4f093deeda6a6347e728d3e97e32d0887b5e49dac5705cb7b50d8721a3a41c; retrieved 2026-09-15T06:47:12.654Z.