I have not found any evidence of any nav-aids having been installed in the X-15.
For practical purposes,a straight-line flight and tracking range was established,commencing over Wendover AFB in Utah to Edwards AFB with control and telemetry stations at Ely and Beatty.
The launch B-52 would be guided by the ground control stations to position it at the correct place in space for count-down and launch.The exact point was determined by whether it would be a high-speed mission using the full 485 mi. distance or a shorter distance for high-altitude flights.
Weather conditions had to be acceptable for a full let-down and approach to be made in visual conditions.
The flight was planned to allow the X-15 to arrive overhead Edwards AFB at 15,200 ft altitude and 240 KIAS.Downwind turn would follow at 8,700 ft and 240 KIAS.Final turn followed at 5,800 ft/240 KIAS,flare started at 3,200 ft/240 KIAS.Speed was bled off until touchdown occurred at 180 KIAS.
Communication was by UHF.
Launch altitude was 38,000 ft.
"Luck and superstition wins all the time"!