The airfield’s immense hangar dominates the flight apron and appears much as it did when World War II vintage B-17s roared down the runway. Construction of the airfield began in July 1942. The original hangar plans were soon modified, increasing the height and length of the building, likely to accommodate the larger B-29s. Crews at Lewistown, however, trained exclusively on the various models of B-17s. Hangar construction crews laid out the lumber for the bowstring trusses on site, assembled them for fit, and then took them apart to cut the grooves and glue and spike the pieces together. The airfield accommodated one squadron in training at a time with nine B-17s to a squadron; five of the hangar’s six bays could accommodate five of the huge planes, stacked in like sardines. Before a training mission, the B-17 crews would line up outside the hangar to await the bombardier. Armed guards escorted him to the Norden bombsight shelter to retrieve the top-secret device and then escorted him to the hangar and the plane. The process was repeated upon the crews’ return.