This supercharger (Serial No. 1) was installed in the Wright Apache XF3W-1, Bureau No. 7223, flown by Apollo Soucek in 1930 when he made a world record altitude flight to 43,166 ft over Washington, D.C. This is a NACA. Model 2E Roots-type blower case built by the Allison Engineering Company for the U.S. Navy Bureau of Aeronautics. It is one component of the supercharging system that also included an air intake duct (or scoop), a driveshaft, intercooler, and exhaust. This system was connected to a Pratt & Whitney Wasp R-1340B engine that powered the XF3W-1 aircraft, and it made possible the high-altitude record.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.