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ERA19LA186 · Alisport SILENT 2 ELECTRO

4 Jun 2019 · Danbury, CT, United States Possible conflict

Alisport SILENT 2 ELECTRO · Accident: fuel exhaustion on approach

From Danbury Municipal Airport (DXR) to Danbury Municipal Airport (DXR)

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Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.

Event

NTSB case
ERA19LA186
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
0
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

Alisport SILENT 2 ELECTRO

Aircraft type
Alisport SILENT 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
N66911
Operator
Unknown
Onboard fatalities
Unknown
Route
From Danbury Municipal Airport (DXR), Danbury, CTTo Danbury Municipal Airport (DXR), Danbury, CT
Aircraft age
About 3 years (built 2016)
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
Approach
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
Fuel exhaustion
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 systems
  • Personnel issues › Action/decision

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot was conducting a personal flight in an electrically-powered, self-launching motor glider. He stated that, while returning to the departure airport at the conclusion of the flight, the glider encountered sink and he turned on the electric motor, but it produced “no thrust.” The glider continued to descend and impacted a house about 2 miles from the airport, resulting in substantial damage. The pilot reported that there were no mechanical failures or malfunctions with the glider that would have prevented normal operation before the accident and that the accident might have been prevented with “better management of power and understanding of battery power source.” Data from the engine control unit indicated that the motor was used for about 13 minutes during the taxi, takeoff, and climb. The motor was used again about 5 hours into the flight for about 19 minutes, and again about 5:49 hours elapsed flight time, for about 32 minutes. The final activation of the motor occurred at 6:21 elapsed flight time; the accident occurred at an elapsed flight time of about 6:22. According to the glider manufacturer, the battery supplied power for takeoff and an additional 40 minutes of use thereafter. During the accident flight, the motor was used for a total of over 1 hour. Given this information, it is likely that the pilot had exhausted the available battery power and that the motor was no longer able to provide sufficient thrust to sustain flight.

Probable cause

The pilot’s inadequate inflight management of the motor glider’s available battery power, which resulted in the inability of the electric motor to provide sufficient thrust to sustain flight in an environment where no atmospheric lift was available.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ERA19LA186
Event ID
20190605X04640
Case number
ERA19LA186
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: 38e6ac8fad2c3a1fcabe6e24354677251ff71e9b812080bf38f6db61ac794110; retrieved 2026-09-16T09:09:19.066Z.