Brit Watchkeeper drone crashed because blocked sensor made algorithms crash

File pic, Crown copyright

A British Army Watchkeeper drone stalled itself and crashed into the sea on a bad weather flight test, military investigators have said – though most of the wreckage was never found. Investigators concluded that one of its pitot probes used for reading the aircraft’s speed and angle of attack (AOA) became blocked, causing the Watchkeeper’s onboard flight control logic to enter an erratic series of climbs and dives until it stalled itself and flopped into the sea. The Watchkeeper crash investigators stated:

“From its detailed analysis,” wrote Air Marshal Gray in her formal comments on the Service Inquiry (SI) report, “the SI concluded that the design of [Watchkeeper’s] air data system limited its ability to fly safely in cloud and precipitation.”

Source: www.theregister.co.uk