> Instead of flying the aircraft over test antennae, the airframes (usually minus their tails) are suspended upside-down, under or near the instrumentation.
Why not make a hole in the ground and put the antennae under the airplane that way?
Why not make a hole in the ground and put the antennae under the airplane that way?
Since "flying over test antennae" was an option, it shouldn't be a problem that there's solid ground (the bottom of the hole) underneath the test equipment.
I think the real answer is that they need more angles than keeping the aircraft flat and level and putting the antennae below it would provide. The aircraft have to be suspended anyway, so they can be rotated and have different profiles measured.