As to a tilt rotors rotor radar cross section. The rotor blades in airplane mode operate at high angles which provides the same faceting effect as on a F117 to deflect radar from returning to its source. NAVAIR tried a Lawerence Livermore airframe mounted radar blade tracker which worked ok when the target section of the blade was perpendicular to the tracker, but useless with even a few degrees of pitch as the return was deflected. The proposed solution was to add a 360 degree radar reflector to the blade to ensure a return. Obviously this was rejected as stupid. V-22's still use optical trackers for a rare maintenance action.
Note: Radar cross section is closely guarded, has little to do with presented disk area (disk presented solidity somewhat), and something a Staff Sargent would never have a clue of.
Last edited by The Sultan; 6th May 2017 at 17:48.