SR-71, chased by a "clean" F-104 (no external tanks or weapons) at Edwards AFB, or Palmdale - I can't recall the buildings and runway. The starfighter could probably keep up as the SR has a lower T/W Thrust to Weight, but would very quickly run out of gas.
All test flights have a chase aircraft, whose duty is simple: keep the TP from hitting the ground. Test flying is intensely demanding on attentional resources, the guy/gal is always referring to the test "card" with the necessary parameters, speed altitude, G, switch settings, etc and continually talking to Test Ops, who are monitoring the data. Stick, Search, Shut Up is the brief for the chase aircraft. I flew test chase in the T-38 for a year at Edwards. Fascinating.
All test flights have a chase aircraft, whose duty is simple: keep the TP from hitting the ground. Test flying is intensely demanding on attentional resources, the guy/gal is always referring to the test "card" with the necessary parameters, speed altitude, G, switch settings, etc and continually talking to Test Ops, who are monitoring the data. Stick, Search, Shut Up is the brief for the chase aircraft. I flew test chase in the T-38 for a year at Edwards. Fascinating.