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An Army Watchkeeper drone tried to land. Then meatbags took over from the computers

Operators cut throttle during go-around. Aircraft crashed

A British Army Watchkeeper drone that crashed near its home base of Aberporth in south Wales did so after its crew overrode its autopilot, causing the unmanned aircraft to hit a tree.

The Watchkeeper, tail number WK050, was destroyed in the June 2018 crash, according to the BBC, which obtained a copy of an internal Ministry of Defence report using Freedom of Information laws.

The MoD refused to supply The Register with a copy of the same report.

According to the Beeb, WK050 was set to land at West Wales Airport in Aberporth. Watchkeepers fly semi-autonomously; human operators can select waypoints on a screen or choose certain commands for it to carry out automatically, including landing. There is no Xbox-style stick-and-rudder feature for manual flying.

Watchkeeper is a customised version of an off-the-shelf drone design which is built by Thales, the French defence 'n' aerospace company. Israeli company Elbit's Hermes 450 unmanned aerial vehicle (UAV), upon which the Watchkeeper is based, does have a manual override feature. This was not included on the 54 aircraft ordered by the UK.

When it landed at Aberporth, WK050 "landed long", reported the BBC. This means that instead of touching down at the correct point towards the start of the runway, giving it a nice long distance in which to harmlessly roll to a stop, the drone was further along than it ought to have been – risking it overrunning off the far end, damaging the aircraft.

Thus, the onboard computer followed its programming and "auto-aborted as it approached the end of the runway". The drone throttled up to full power and took off again, ready to fly itself around in a circuit and have another go at landing. Such things are a fact of life in aviation, whether humans or computers are trying to land.

However, WK050's human operators seemingly became confused at this point – and cut the throttle. WK050 "glided over the road" at the end of the runway and "crashed into a tree" around 900 metres beyond the end of the runway.

"Had no action been taken by the crew the AV (aerial vehicle) would have completed its automatic go-around, from which it could have been commanded to conduct a further approach," the report said.

The Watchkeeper programme has been dogged by poor software design and human error since its inception in 2005.

Watchkeeper is flown by Army operators drawn from 47 Regiment Royal Artillery. So far five of the unmanned aeroplanes – nearly 10 per cent of the entire fleet – are known to have crashed, with the MoD doing its best to hush up crashes unless they happen within eye or earshot of humans. Two were destroyed by crashing into the Irish Sea, which was unknown by the public until the news was blabbed by an admiral at a defence trade show a few years ago.

Another was written off after its operators disabled anti-crash software protections. The Watchkeepers' software itself has also come under fire, as was revealed earlier this year.

The crash-dogged Watchkeeper programme is £400m over its original budget of £800m, totalling £1.2bn of public money so far, and has done no operational (warzone) flying other than a token deployment for three weeks in Afghanistan in the early part of this decade. ®

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