ASN Wikibase Occurrence # 225551
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Thursday 9 May 2019 |
| Time: | 10:38 LT |
| Type: | Matternet M2 V9 |
| Owner/operator: | Matternet Inc |
| Registration: | SUI-9903 |
| MSN: | M2-0033 |
| Fatalities: | Fatalities: 0 / Occupants: 0 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | Ob der Hueb -
 Switzerland
|
| Phase: | En route |
| Nature: | Cargo |
| Departure airport: | Universität Zürich (UZH), Irchel |
| Universität Spital Zürich (USZ), Fluntern | |
| Investigating agency: | STSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The Matternet M2 V9 drone crashed shortly after departure.
It was a mission on behalf of Swiss Post, during which blood samples had been transported on the outbound flight to the University of Zurich (UZH) Irchel. The accident occurred without load on the return flight to the University Hospital of Zurich (USZ), Fluntern. Swiss Post was the client and service provider and purchased the service from Matternet being the operator of the drone.
About one minute after take-off from the University of Zurich (UZH) Irchel, the drone automatically triggered the flight termination system (FTS) and initiated an emergency descent with a parachute. After ejection of the parachute, the connecting rope broke and the drone hit the forest floor near playing children without deceleration. The drone was destroyed on impact; no one was injured.
Causes
The accident, in which the drone triggered the automatic flight termination system and ejected the parachute during cruise flight, was due to increasing vibrations of unknown origin in conjunction with the lack of resilience of the flight controller software used.
After the parachute ejected, the connecting rope was cut at the sharp-edged, drone-side attachment point and snapped, causing the drone to hit the ground without deceleration.
The investigation identified the following factors, which did not influence the occurrence and course of the accident, but nevertheless represent a factor to risk:
• After the flight termination system was triggered, the audible warning signal was not heard by people not far from the crash site.
• Even when descending to the ground on its parachute, the drone’s impact energy would have clearly exceeded the limit value that had been usual in practice up to then.
• There were no stickers on the drone that could clearly interpreted as danger and warning labels .
• Redundancy of the propulsion concept
Accident investigation:
 |
|
Sources:
STSB
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 30-Jun-2019 13:02 | harro | Updated [Time, Source] |
| 14-Jun-2023 10:09 | harro | Updated [[Time, Source]] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation