Radar cross-section this information is new to me. This video is somewhat incorrect, but it brings up the subject of radar cross-section yes the SR 71 did change the radar cross-section by using RAM radar absorbing materials. Well-known author, Jim Goodall wrote this in the comments to me recently. In a sit down with Bob Gilliland many decades ago, I asked him what the Radar Cross Section was for the SR-71. He said that at subsonic speeds, the RCS was about 20 square inches. At Mach 3.2, the RCS