A new post is up at
RetroMechanix.com presenting the Robert C. Stroop SP-6 and SP-7 "Speed Plane" projects of 1935-9:
These were a pair of designs submitted to the US Army Air Corps which featured a folding scissor "X-wing" to convert the aircraft from biplane to monoplane configuration, the intention being to combine the short field length and climb capabilities of the former with the speed of the latter. The article features 10 images reproducing rare correspondence, drawings, and photos relating to these unusual and innovative projects.
-Jared