with conical flash hiders on the guns, an AN/APS-6 radar pod below the nose, and a second cockpit with a raised canopy behind the pilot's canopy for the radar operator. The headroom in the rear cockpit was limited, requiring radar operators who were preferably short in stature. One of the initial production P-38s had its turbosuperchargers removed, with a secondary cockpit placed in one of the booms to examine how flight crews would respond to such an "asymmetric" cockpit layout. One P-38E was fitted with an extended central nacelle to accommodate a tandem-seat cockpit with dual controls, and was later fitted with a laminar-flow wing. Very early in the Pacific War, a scheme was proposed to fit Lightnings with floats to allow them to make long-range ferry flights. The floats would be removed before the aircraft went into combat. Concerns arose that saltwater spray would corrode the tailplane, so in March 1942, P-38E 41-1986 was modified with a tailplane raised some , booms lengthened by 2 ft, and a rearward-facing second seat added for an observer to monitor the effectiveness of the new arrangement. A second version was crafted on the same airframe with the twin booms given greater sideplane area to augment the vertical rudders. This arrangement was removed and a final third version was fabricated that had the booms returned to normal length but the tail raised . All three tail modifications were designed by George H. "Bert" Estabrook. The final version was used for a quick series of dive tests on 7 December 1942 in which Milo Burcham performed the test maneuvers and Kelly Johnson observed from the rear seat. Johnson concluded that the raised floatplane tail gave no advantage in solving the problem of compressibility. At no time was this P-38E testbed airframe actually fitted with floats, and the idea was quickly abandoned, as the U.S. Navy proved to have enough sealift capacity to keep up with P-38 deliveries to the South Pacific. Still another P-38E was used in 1942 to tow a Waco troop glider as a demonstration. However, there proved to be plenty of other aircraft, such as Douglas C-47 Skytrains, available to tow gliders, and the Lightning was spared this duty. Standard Lightnings were used as crew and cargo transports in the South Pacific. They were fitted with pods attached to the underwing pylons, replacing drop tanks or bombs, that could carry a