First flight not until 2001

Published: 6/7/2000

The Deputy General Director of SibNIIA (Siberian Scientific Research Institute of Aviation) Stanislav Kashafutdinov based in Novosibirsk, has reported that the first flight for the Sukhoi S-38L agricultural aircraft has been postponed until 2001. SibNIIA is currently contracted by Sukhoi to optimise the S-38L aerodynamics, which, according to Kashafutdinov, currently demonstrate a lift/drag ratio of 15 on the clean aircraft and with equipment fitted still manages a credible ten. Kashafutdinov claimed that the design work on the S-38L design had been frozen, although the preparation of manufacturing documentation was 'nearly completed'. The aircraft's conventional low wing design originally started in 1993, with the construction of the prototype reported to have begun in January 1994. The plane is powered by a M-337 piston engine capable of operating on the readily available AI-92 automobile petrol with an internal fuel capacity of 210 litres. The original engine, the 340hp VOKBM M-14P was replaced by the smaller Czech 210 hp M-337AK.1 produced by LOM, as the cheaper and lighter of the two options. According to Boris Rakitin, General Director of Sukhoi Advanced Technologies however, the rising cost of the imported engine may lead to changes as it is in danger of pricing the aircraft out of the reach of its potential market. The price differential would however, have to be substantial, given the Russian's engines weight and the design changes involved to fit it into the air frame. Working parameters for the aircraft are an operational height of 1-15 m at a speed of 180-200 km/hr, with a lifetime set at ten years or 3000 hours. The projected unit price of the aircraft in the last three years has also fallen in US dollar terms from $100,000 in 1997 to $55,000-70,000 reflecting the use of ordinary aluminum alloys in its construction. The 1200 kg aircraft gives, according to Kashafutdinov, higher pilot protection than any other crop sprayer. Placing the 600litre chemical tank between the engine and pilot's cockpit increases the survivability of the pilot in a crash. The S-38L also has a cutter wire arrayed from the top of the canopy to the tail with the intention of cutting wire the aircraft may fly into during low-level flight. The aircraft's airfoils and wing shape guarantee the sprayer a stall speed of 76 km/hr. The aircraft also has considerably improved ventilation to prevent inhalation of the chemical by the pilot. The position of the pilot is however, regarded as poor during taxiing as the pilot is unable to see the wheels of the aircraft hidden under the low forward wing. Kashafutdinov was however, highly critical of some of the aircraft currently available for agricultural roles. The agricultural Il-103, he described as 'incompetently designed for the chemical spraying role'. He also said that the Aviatika-890 'Farmer' ultra-light exposed pilots to inhalation risk by placing the chemical tank near the pilot and there had been 'numerous' accidents as a result. The aging An-2 he said, had to fly too high because of its weight with the resultant inaccurate laying of chemicals, expensive both for the operator and the environment.

Article ID: 1846