8 June 1966 – The “second North American XB-70A Valkyrie prototype, 62-0207, crashes at Edwards Air Force Base, California, following a mid-air collision with a Lockheed F-104 Starfighter, NASA 813, previously 013, while the aircraft were in close formation for a photoshoot at the behest of General Electric. The pilot of the F-104N, Dr. Joseph A. Walker… and Maj. Carl Cross, the copilot of the XB-70, are killed.” (1)
“The USAF summary report of the accident investigation stated that, given the position of the F-104 relative to the XB-70, the F-104 pilot would not have been able to see the XB-70’s wing, except by uncomfortably looking back over his left shoulder. The report said that Walker, piloting the F-104, likely maintained his position by looking at the fuselage of the XB-70, forward of his position. The F-104 was estimated to be 70 ft (21 m) to the side of, and 10 ft (3 m) below, the fuselage of the XB-70. The report concluded that from that position, without appropriate sight cues, Walker was unable to properly perceive his motion relative to the Valkyrie, leading to his aircraft drifting into contact with the XB-70’s wing.” (2)
Source: (1) Wikiwand List of accidents and incidents in 1966; (2) Aviation-Safety.Net