424 was a straight-wing design similar to the B-45, B-46 and B-48 it competed with. Analysis by Boeing engineer Vic Ganzer suggested an optimum sweepback angle of about 35 degrees. By September 1945, the Braunschweig data had been worked into the design, which re-emerged as the Model 448, a larger six-engine design with more robust wings swept at 35 degrees. Another re-work moved the engines into strut-mounted pods under the wings due to concerns of the uncontained failure of an internal engine could potentially destroy the aircraft via either fire or vibration. The resulting B-47 was hailed as the fastest of its class in the world during the late 1940s, and trounced the straight-winged competition. Boeing's jet-transport formula of swept wings and pylon-mounted engines has since been universally adopted. In fighters, North American Aviation was in the midst of working on a straight-wing jet-powered naval fighter, then known as the FJ-1; it was later submitted to the United States Air Force as the XP-86. Larry Green, who could read German, studied the Busemann reports and convinced management to allow a redesign starting in August 1945. The performance of the F-86A allowed it set the first of several official world speed records, attaining on 15 September 1948, flown by Major Richard L. Johnson. With the appearance of the MiG-15, the F-86 was rushed into combat, while straight-wing jets like the Lockheed P-80 Shooting Star and Republic F-84 Thunderjet were quickly relegated to ground attack missions. Some, such as the F-84 and Grumman F-9 Cougar, were later redesigned with swept wings from straight-winged aircraft. Later planes, such as the North American F-100 Super Sabre, would be designed with swept wings from the start, though additional innovations such as the afterburner, area-rule and new control surfaces would be necessary to master supersonic flight. The Soviet Union was also quick to investigate the advantages of swept wings on high speed aircraft, when their "captured aviation technology" counterparts to the western Allies spread out across the defeated Third Reich. Artem Mikoyan was asked by the Soviet government's TsAGI aviation research department to develop a test-bed aircraft to research the swept wing idea — the result was the late 1945-flown, unusual MiG-8 Utka pusher canard layout aircraft, with its rearwards-located wings being swept back for this type of research. The swept wing was applied to the MiG-15, an early jet-powered fighter, its maximum speed of outclassed