A little old now, and apologies if you saw it at the time, but reading about flyway problems brought this to mind:
www.theregister.com
The TL;DR version is that the US Army lost contact with a drone shortly after takeoff, whereupon it flew into a tree. Over 600 miles away.
US military drone goes AWOL, ends up crashing into tree 623 miles away
Army baffled as Shadow goes invisible
The TL;DR version is that the US Army lost contact with a drone shortly after takeoff, whereupon it flew into a tree. Over 600 miles away.