212man is correct.....the aircraft was being controlled remotely.....simple automation re engine controls.
Notice the rather large and high berms all round the aircraft.....and note that Aberdeen Proving Grounds is focused upon things that go bang.....Fort Eustis in Virginia is the maintenance training base....and Fort Rucker is the home to the Aviation....and now days the military facility in Huntsville, Alabama does some aviation related testing.
From the Aberdeen Proving Grounds historical data.....During the period of conflict in Southeast Asia, APG reentered a period of intense growth and new direction.
The recreation of the Ordnance Officer Candidate School (OCS) took place and the unusual contributions of the Land Warfare Laboratory increased.
The intensive developmental efforts and scientific contributions of the Ballistic Research Laboratory, the Army Materiel Systems Analysis Activity and the Human Engineering Laboratory made the decade of the 1960s and 1970s an extraordinary time in APG's history.
The Ordnance Center and School's contributions included three-shifts-a-day training at the height of the conflict.
A significant change was made on July 1, 1971, when Edgewood Arsenal, the former chemical center and current chemical research and engineering center for the U.S. Army, was merged into APG. Although the mission functions remained separate entities, the real estate and base operations functions were operated as one post. From this point on, APG was the common identifier for both areas.