ERA21FA239 · Schweizer SGS 1-35
Schweizer SGS 1-35 · Accident: loss of control in flight during initial climb
Event
- NTSB case
- ERA21FA239
- 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
Schweizer SGS 1-35
- Aircraft type
- Schweizer SGS-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
- N2878H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 44 years (built 1977)
- 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
- 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
- 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
- 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 accident flight was the pilot’s first flight in the glider make/model, and he indicated to the wing runner that he was “hesitant” about the flight. Witness statements and recorded data indicated that, just after takeoff, the glider released from the tow plane about 170 ft above ground level, while in a 25° right turn over the runway departure end. The glider continued the right turn and stalled about 1.4 seconds later, impacting airport property 13 seconds after the stall. Examination of the wreckage did not reveal any preimpact mechanical malfunctions.
Toxicology testing revealed the presence of the sedating antihistamine diphenhydramine in cardiac blood and urine, indicating that the pilot had taken some allergy, cold, or sleep-aid medication before the accident. Even considering two-to-three-fold postmortem redistribution of diphenhydramine, the concentration in the pilot’s blood appeared to be at therapeutic levels. Compared to other antihistamines, diphenhydramine causes marked sedation; impaired cognitive and psychomotor performance may also be observed. While the impairing medication diphenhydramine was detected, it is unlikely that the effects from the pilot’s use of diphenhydramine contributed to this accident. Although the reason for the pilot’s release from tow at low altitude could not be determined, the accident is consistent with his failure to maintain airspeed during the turn back to the runway, which resulted in an aerodynamic stall and impact with terrain.
Probable cause
The pilot’s low-altitude release from tow for reasons that could not be determined, and his subsequent exceedance of the glider’s critical angle of attack while returning to the runway, which resulted in an aerodynamic stall and impact with terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21FA239
- Event ID
- 20210606103217
- Case number
- ERA21FA239
- 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, cause areas. 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: 6ef63b79540ce6cc24b3aaf4e656079cef48a4f7051c7d9167cc906c9ef16ed7; retrieved 2026-09-15T07:29:29.944Z.