The Army had a vertical reference mission in 1964, for which they devised a creative guidance approach.
The mission involved carrying a sling load at the end of a 2000 ft cable, and flying the load around a specific course, and then landing the load precisely and softly, back at the start point. Moonless nights only.
The load was a full size model of the UH-1B and it was built with a double skin, separated by a dielectric. The skin was separated into a good number of sections, each with individual electric connections to a battery powered tape recorder.
The mission, flown by a CH-47A, would begin by landing next to the model and hooking up the sling. A WWII searchlight was oriented vertically, with a beam that extended well beyond the needed 2000ft. The ship was hovered up the beam, slowing near 2000ft so as to gently lift the model.
After pickup the beam was shut down and the CH-47 would fly assigned headings on a dedicated FT Bliss radar.while the assigned weapons for the night would fire live ammo at the model. each night flown involved a different weapon, varying from 30 cal to 40mm. Each hit on the model would be recorded as the projectile would short the two skins in that area.The return of the model to the takeoff site involved the reverse searchlight procedure. The CH-47 would stay a bit off to one side of the beam so as to keep the cable from draping all over the model.
Simple and innovative, the testing was almost completed, when one night with the larger caliber weapon in use the sling was shot away half way to the CH-47 and it was decided that sufficient data had been collected.