 When Andrei Tupolev likewise used the Junkers firm's techniques for all-metal aircraft construction, his designs ranged in size to the enormous, 63 meter (206 ft) wingspan eight-engined Soviet "Maksim Gorki", the largest aircraft built anywhere before World War II.The de Havilland DH.88 Comet racer of 1934 was one of the first designs to incorporate all the features of the modern fast monoplane, including; stressed-skin construction, a thin, clean, low-drag cantilever wing, retractable undercarriage, landing flaps, variable-pitch propeller and enclosed cockpit.Unusually for such a highly stressed wing at that time it was still made of wood, with the thin stressed-skin design made possible by the appearance of new high-strength synthetic resin adhesives.