MOSCOW --- The aircraft plant in Kazan has started restoring the key technologies in the interest of producing the upgraded Tu-160 (NATO reporting name: Blackjack) strategic bomber. A schedule has been approved for the manufacturing of the most important part of the future aircraft - the titanium main longitudinal beam.
Experts point to the significance of the fact and remind that the shop had been virtually wiped out following the collapse of the Soviet Union. The company admits that many of its facilities have been neglected, according to the BUSINESS Online news portal.
The Kazan Aircraft Plant, an affiliate of Tupolev, has started restoring a unique technology - the annealing and welding of titanium parts by means of the ELU-24 electron beam welding and UVN-45 annealing units.
The Kazan Aircraft Plant awarded two contracts for restoring the Tu-160 manufacturing equipment in March 2016. Both are to be carried out by March 30, 2017. Elektromekhanika in the city of Rzhev undertook to square the UVN-45 away for 948 million rubles ($16.5 million), while a subcontractor for rebuilding the ELU-24 was not selected at the time. According to the corporate newspaper, Rzhev-based NITI Progress has been selected for this job. It will be paid 710 million rubles ($12.3 million).
In the later 1970s, the productionizing of the Tu-160 necessitated a total reconstruction of the Kazan Aircraft Plant. Among other things, the construction included the erecting of a new building that housed the titanium unit machine assembly shop and the above-mentioned units. The upgrades also included the unique equipment for processing 20-m-long monolithic variable-thickness titanium-alloy slabs, because such slabs make up 38% of the Tu-160’s airframe.
The mainstay of the bomber is its main longitudinal beam 12.4 m long and 2.1 m wide, around which the other airframe components were mounted. For instance, the wing panels were hinged on its flexible joints. In order to manufacture the main longitudinal beam, the neutral or vacuum electron beam welding was developed as manufacturing process.
"As is known, titanium cannot be welded in the air, because it goes ablaze and the fire cannot be put out. Therefore, it is welded either in vacuum or in a neutral environment," Nazir Kireyev, an advisor to Tatarstan’s prime minister, told BUSINESS Online. "High precision up to a fraction of the millimeter is a must in welding."
The beam was milled from two halves that were then welded together in a vacuum chamber with the use of special additives and brazing fluxes. This welding technique is reportedly remains unique and may well be regarded as the country’s priority.
"This kind of welding has been performed by the Kazan Aircraft Plant alone and it emerged in connection with the Tu-160 only," Kireyev reminded. "No other aircraft has had a titanium wing center section."
"The ELU unit is used for wing center section welding. There will be no upgraded Tu-160, unless we re-learn how to make the beam," a BUSINESS Online source in the aircraft industry says. "As is known, money allocated for the rebuilding the [ELU-24 and UVN-45] units is big. Will the job be done on time? It is hard to say, because the units have been out of repair seriously and for a long time, since the 1990 literally wrought havoc at the shop."
"Everything has been neglected there," the Vperyod corporate newspaper admitted with respect to the two units. According to the paper, there even has been no relevant paperwork left. At the same time, the authors of the article are rather optimistic: "The team of Shop 45 has been much spoken about of late, because a new machine assembly shop is being set up there. No sooner had the director ordered the establishing of Shops 45 and 40 that the results were produced. Kazan-based Giproniiaviaprom approved a new layout of the shop. Each stage of the work was planned in detail. The ELU-24 and UVN-45 units are to be tested and accepted and the manufacture of the components of the main longitudinal beam and wing pivot assembly is to begin by March 30, 2017."
According to Shop 45 Manager Alexei Potapov, a schedule has been approved for the gradual manufacture of the Tu-160’s advanced main longitudinal beam and wing pivot assembly. In addition, the shop’s roof is being repaired and the commissioning work is underway in support of installing the advanced vacuum, control, cooling and electric automation systems.
The Paton Institute in Kiev supervised the electron beam welding and vacuum annealing in the 1970s.
"Right, the work was supervised by the Paton Institute. It was situated in Ukraine, but this does not mean it was all-Ukrainian. Mind you, 25 [research] institutes were involved in the making of the electron beam welding unit. Now, everybody able to do at least something in this sphere will be contracted," Kireyev told the BUSINESS Online news portal.