An Israeli-made radar drone, one of six ordered by the Swiss Armed Forces in a $264 million defence deal, crashed due to high winds, an investigation report said.
Switzerland ordered the Hermes 900 drones, made by Israeli defense electronics company Elbit Systems, in 2015. But one was destroyed after crashing on a test flight in the Israeli desert last August.
The crash and subsequent investigation under the direction of the Israeli Ministry of Transport has delayed delivery, scheduled initially for late 2019, until next year.
“According to the accident report, the crash was due to the fact that the V-tail unit became detached from the fuselage of the drone due to unexpectedly strong oscillations. The drone could thus no longer be controlled and crashed,” the Swiss government said.
“The Israeli manufacturing company Elbit Systems Ltd was able to eliminate the cause of this problem with regard to further production of the drone, without changing the drone’s design.
"The damage is to be borne entirely by Elbit Systems Ltd. The crash occurred on a test flight of the drone. This resulted in total loss of the drone, but no damage to persons or third-party damage.”
An upgraded version of the Hermes 900 will now be supplied to Switzerland.
One of the enhancements is the provision of a heavy fuel engine, which will enable the aircraft to achieve an increased rate of climb after take-off – a key requirement in mountainous country.
The Swiss government said the new reconnaissance drones, which have a "sense-and-avoid" sensor system to detect aircraft to avoid collisions, would be delivered from mid-2022 to the summer of 2023.
"Approval of the radar for the sense-and-avoid system is planned for the end of 2024.
"The current delays are due, on the one hand, to the time and effort required for certification with the Civil Aviation Authority Israel, which was underestimated by the supplier, and on the other hand, to the delayed development of the radar system for sense-and-avoid," said the Swiss government.
"In addition, the Covid-19 pandemic has disrupted industry and has severely limited co-operation with the supplier due to travel restrictions and quarantine requirements.
"Until the approval of the sense-and-avoid radar, the Hermes 900 HFE drone will be deployed in uncontrolled airspace and with an escort aircraft by day."