Published: 5/22/1998

In February, Yakovlev design bureau was asked by the Federal Aviation Service of the Russian Federation (FAS RF) to look at the possibility of a long-range version of the Yak-42D airliner as a possible replacement for the ageing Tu-134. The new version, unofficially named Yak-42DD, is seen by Yakovlev engineers as a derivative of the current production model with reduced empty weight. The engineers found that the empty weight of the basic aircraft can be reduced by 1526kg by replacing old and heavy avionics and equipment with a modern foreign suite. Further, as much as 2300kg of additional fuel can be carried in the existing fuel tanks provided their analogue contents sensors are replaced with new digital ones. Thus modified, the airliner will meet the mandatory requirement to have a range of no less than 4,000km with 90 passengers (and reserve fuel in accordance with AP-25/FAR-25). The empty weight can be further reduced by shortening the fuselage by 160mm. While the maximum take-off weight limitation remains unchanged, this would allow the aircraft to take more fuel with a fixed commercial load. Installation of AlliedSignal avionics suite might save another 200kg. With all that in place, the Yak-42DD would have a ferry range in excess of 6000km. But this figure can be even greater if Motor SICh agrees to install FADEC system developed for the D-436 on the production D-36 engines in use on the Yak-42. Separately, Yakovlev has asked Motor SICh to introduce "extreme thrust" mode on the newly-built D-36s so as to allow the airplane to fly with higher weights from hot-and-high airfields. In May, Yakovlev submitted its proposals on the Yak-42DD to FAS RF. The Service says that if the Yak-42DD meets its expectations, then it would attempt to approach the Government and financial structures with a proposition to compile a state investment programme on replacing the Tu-134s for the new version of the Yak-42. Yakovlev says that currently the routes regularly flown by the Yak-42s average at 1,400km. Meanwhile, operators continue to show an interest in the current production model. In 1997, the aircraft production factory in Saratov delivered four Yak-42s. In May the factory rolled out a new Yak-42D tailored to specific requirements of FAPSI, the Federal Agency of Governmental Communications and Information. The aircraft is said to be fitted with special communications equipment, but Yakovlev refuses to specify it. However, the design bureau confirms that the aircraft has a luxurious VIP cabin, similar to that on the LUKOil Yak-42D. According to sources at Yakovlev, RAO Gazprom has recently ordered one more Yak-42D in VIP version, again with VIP cabin similar to that of the LUKOil aircraft. It is known that the LUKOil-type VIP cabin costs $0.35m. The number of serviceable Yak-42s is now 148, of which 50 are fitted with seats with reclining backs in place of original fixed ones (which save some weight). Yakovlev says that the improvements which are to be introduced on the Yak-42A will gradually be introduced into the production Yak-42D model, without waiting for the Yak-42A program to get fully approved and certificated by MAK, the Interstate Aviation Committee. This applies to the new APU, in-flight operable spoilers, kitchen equipment, seats and so on. Yakovlev says it already holds complimentary certificates on installation of some of these items. In fact, the last ten aircraft built were fitted with new comprehensive kitchen equipment and seats with reclining backs. In parallel, operators themselves replaced the original seats on 40 older aircraft. Out of the 148 operable Yak-42s, 87 are in service with Russian operators. At the end of 1997, Yakovlev obtained a complimentary certificate for the Yak-42, permitting a lifetime of 20,000 flight hours and 14,000 flight cycles. The work is in progress to increase these figures to 25,000 hours and 20,000 flight cycles. Out of 135 Yak-42s in service with CIS and Baltic operators, 23 have already logged over 15,000 flight hours. Yakovlev design bureau has almost completed the programme of overhauling airframes with over 20,000 flight hours on wings. The necessary work on such an airframe would require 60,000-70,000 man-hours. Yakovlev has developed documentation on fitting the Yak-42 with Global Positioning Systems in addition to its existing avionics suite. The company also prepared documentation on installation of Collins avionics. In the meantime, work on the Yak-142 model, with D-436 engines and extended fuselage accommodating 156-160 passengers in an all-economy layout, is halted due to insufficient funding. Yakovlev estimates that some $60m would be required to prepare a comprehensive pack of documentation for this model. Some independent financiers, including INCOM bank are said to be interested in funding this effort, but so far no commitments have been made. (IN598.6) (VK)

Article ID: 161