Cut out some packing from foam that can be used to brace the centre-section. I have used an old yoga-mat here, firstly to achieve a state of supreme consciousness during flight and secondly because I refuse to spend money on the four-by-eight sheet of PU insulation foam that I would generally use. The reason for including foam here besides overall rigidity is to dampen vibrations within the surface of the centre-section so that the flight-control computer is not ~ literally and figuratively ~ rattled.
