This rocky hill was the crash site of a Stingray Deluxe. Two infantry fighting vehicles with emergency personnel and their robots were dispatched to rescue the pilot, secure the site and recover the aircraft on Saturday, October 23, 2077.
They were successfully performing their mission, until radiation from the nuclear detonations swept through the area killing them were they were. Now, two hundred and ten years latter the site remains untouched. It's sentry bot successfully guarding the premises and the utility Protectron wandering around the aircraft.
Military APCs appears only in Fallout 4.