Alisport SILENT 2 N66911

Summary

On 4 June 2019 at about 21:00 local time, a Alisport SILENT 2 registered N66911 was involved in an accident near Danbury, Connecticut, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

4 June 2019 at 21:00

Classification

Accident

Location

Danbury, Connecticut, United States

Nearest airport

Danbury Muni (DXR)

Coordinates

41.5982, -72.7558

Aircraft

Alisport SILENT 2

Registration

N66911

Category

Glider

Year built

2016

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Danbury → Danbury

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA19LA186

1 person had minor injuries.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.