|The ANT-35 prototype at an international airshow.|
The design of the this high-speed aircraft able to carry about ten passengers started life as an unplanned project. In May 1934 the Aviation Research Technical Society (Avia-NITO - Aviatsionnoye nauchno-issledovatel'skoye tekhnicheskoye obshchestvo) and the motoring periodical Za roolyom (At the Wheel) announced a competition for a high-speed transport aircraft. The technical requirements were drawn up for both a single-engined and a twin-engined aircraft which were to possess a speed of 400-450 km/h, a range of 1,250-1,500 km, a service ceiling of 7,500 m and be able to carry five to twelve passengers with their luggage.
Several dozen projects were submitted, mainly for twin-engined aircraft, and although none was actually built, the estimated performance figures for the various projects had an influence on the design of future Soviet passenger aircraft. TsAGI did not take part in this competition, but Tupolev decided on his own account to design and build a passenger aircraft as quickly as possible, using the ANT-40 (SB) bomber then under development in A. A. Arkhangel'skiy's team as a basis. Design work on the ANT-35 began on 1st August 1935 and was carried out by Arkhangel'skiy's team. The machine emerged as a twin-engined allmetal low-wing monoplane with a retractable undercarriage. The wings, tail assembly, undercarriage and a number of other design features were taken from the ANT-40. The striving to achieve high speed determined the minimum possible fuselage cross-section, and special care was taken to ensure a tight fit of airframe assemblies and a high-quality external finish. Two French Gnome-Rhone 14Krsd Mistral Major radials (licence-built in the USSR as the 860 hp M-85) with reduction gear were installed. The heat- and soundproofed cabin had ten reclining passenger seats, general and individual ventilation, electric lighting and a heating system. The ANT-35 had all the requisite navigational, flight and radio communications equipment and the latest instruments and aids (autopilot, direction finder and so on) which distinguished it from other Soviet aircraft of that period.
In its construction the ANT-35 incorporated all the latest achievements of aviation technology which added to the aircraft's flying and operational qualities: new close-fitting NACA cowlings, oil coolers buried in the wing roots, hydraulically-operated flaps occupying the entire width of the wing centre section, a one-piece stressed-skin tailplane and rubber shock-absorbers on the engine mounts.
The first flight of the ANT-35 prototype was made by Gromov on 20th August 1936. With a normal all-up weight of 6,620 kg the aircraft achieved a speed of 390 km/h making it one of the world's fastest passenger aircraft at that time.
The prototype ANT-35's major drawback as a passenger aircraft was the lack of headroom in the cabin, and when it was placed in production the height of the fuselage was increased by 0.15 m. This new fuselage was used in the second aircraft, the ANT-35bis which was to be powered by American Wright Cyclone engines or their Soviet-built equivalent, the 820/1,000-hp M-62IR.
Construction of the second prototype at Factory No.156 began in March 1937, and the machine was to serve as the pilot example for a series to be produced in the autumn of 1937. It was transferred for completion and production technology study to Factory No.22 where manufacture was to take place under the designation PS-35. In addition to the dooblyor, two other prototype examples were built at MMZ No.156 and then passed to Factory No.22 for completion. Altogether in 1938-193 Factory No.22 built 9 production examples of the PS-35. The overall number built, including the first two, was 11.
The fact that there was no large-scale production of the PS-35 is due to the fact that in the late 1930s the Soviet Union obtained a licence from the USA to manufacture the Douglas DC-3, one of the world's best passenger and transport aircraft at the time. The DC-3 was produced in the USSR as the PS-84 (Lisunov Li-2) with the same M-62IR engines as the ANT-35 but carrying a far bigger payload in terms of passengers and cargo over a greater distance. These factors were more important for Aeroflot and the VVS than the PS-35's high speed.
The PS-35 served with the GVF for a number of years on international routes (Moscow-Prague and Moscow-Stockholm). Immediately before the outbreak of war in 1941 it also served express short-haul domestic flights (Moscow-L'vov, Moscow-Odessa). The PS-35 saw intensive service as a transport during the Great Patriotic War of 1941 -45 when it was used by a number of independent transport flights for carrying troops, dropping parachutists and partisans in the enemy rear and for delivering blood, medical supplies, ammunition, fuel and food to encircled Red Army units. The machine remained in service until 1944.