Beriev A-50 Mainstay

The A-50 Mainstay is a Russian airborne warning and control system aircraft based on the Ilyushin Il-76 transport plane. Russia adopted the aircraft in 1984, and the Air Force currently has 16-20 A-50 planes, according to various reports. The A-50 Mainstay SDRLO (Long Range Detection System) aircraft is based on a stretched Ilyushin IL-76 Transport in widespread service with Soviet Forces combined with an upgraded "Flat Jack" radar system. Developed to replace the TU-126 Moss (a variant of the Bear bomber), the Mainstay first flew in 1980. It was estimated that at least 12 were in service by 1990, with an annual production rate of five machines per year and about 40 produced by 1992.

The series-produced 11-76, selected as the basis for creating the A-50, was substantially refined in the area of accommodating the radar antenna with a ten-meter (in diameter) radome rotating in flight, along with other antennas, and the creation of systems for electric-power supply, cooling of the gear and accommodating the crew and their life and functional support. The A-50 is outwardly distinguished from a conventional transport aircraft by the onboard radar antenna fairing nine meters in diameter attached to the fuselage by aerodynamic struts. On the ground the fairing seems flat, but this is an optical illusion - a person can stand up straight in the interior of the "saucer."

The aircraft's wings are high-mounted, swept-back, and tapered with blunt tips. There are four turbofan engines mounted on pylons under and extending beyond the wings' leading edges. The fuselage is long, round and tapered to the rear with a radome on the chin. There is a saucer type radome on top of the aircraft. There is a stepped-up cockpit. The tail flats are swept-back and tapered with blunt tips high-mounted on the swept-back, tapered fin, forming a T. The aircraft can stay aloft without refueling for four to six hours and can remain airborne for another four hours with mid-air refueling. The aircraft has a maximum range of 1,800 kilometers, while the radar has a detection range of up to 800 kilometers, and can track 200 targets simultaneously.

The geometry of the CANDID airframe and rotodome a11owed a sonewhat better lo~-alt1tude radar coverage pattern than that of the Modified MOSS. An 1mportant quest1on was the ab111ty of the radar to determ1ne target altitude and to detect low-fly1ng targets. There are three possible techniques to achieve this capabi1ity: a radar with a phased-planar array antenna w1th electronic steer1ng (at least in the elevation plane); multiple-elevation beams; or measurement of time-difference-of-arrival for primary target returns and mult1path.

The A-50's cabin is literally crammed with gear: indicators, walls of units, the metal covers of a powerful transmitter, and instrument panels. It is made impressively and with good quality, and the designers also did not shun design, although the dimensions of units could be reduced severalfold with a more modern element base. But the crew does not completely fill the tanks with fuel because of the weight of equipment, fearing overloads on the landing gear. The Russian gear really is heavier than American gear by approximately one and a half times - that is the developmentlevel of the country's electronics as a whole. But if we Russian set the goal of substantially lightening it, it would lose in radar capabilities and would add additional fuel only for a half-hour of flight.

True, an aerial refueling device is provided, but its probe, which crowns the aircraft nose, essentially is inactive - aerodynamic characteristics, changed in connection with the antenna fairing installation, do not allow forming up behind a tanker as the aircraft is heavily jolted and shaken in the dense airstream.

The crew is not suited by the loud noise and SHF emission, but people do not even have information about the level of biological protection. The reliability of the system equipment leaves much to be desired. When in flight, engineers sometimes dash from rack to rack and transpose units from one niche to another, and each time loosen mounting screws and undo cable connectors.

The previous system was installed in the Tu-95, which is approximately the very same as the Tu-114, with a passenger design and naturally with a toilet and a corner for rest. But in the case of the 11-76 the client (the Air Force) also could have insisted on crew conveniences from the aircraft firm - there were military people on the mockup commission which examined technical proposals. With respect to the noise, it is not simple to avoid, which is why headphones with glycerin fillings are provided. But in some instances the crew prefers a lighterand more convenient set, and in another the supply people are slow. The SHF emission does not exceed permissible limits. That is the conclusion of the Institute of Aviationand Space Medicine. The tail section where the radar transmitter is located is separated by a shielding mesh and there is metallized glass in the windows.

It must be said in honor of Soviet industry that no one else proved able to create an aircraft that performed the same missions as the E-3A AWACS. The British Air Force, for example, having spent about a billion pounds, was forced to drop the development of its own DRLO aircraft and order seven of the E-3A type aircraft from the United States in 1986-87.

But time does not wait, and functional obsolescence is unfortunately not far off for the A-50. The Stealth technology and the prospects for the creation of DRLO aircraft abroad, for example, promise that. It should be noted that the E-3A AWACS is not the sole DRLO aircraft in service. The use of E-2C Hawkeye aircraft is planned along with it, for example. It is noteworthy that the use of the mushroom-shaped radomes over the fuselage is not now envisaged for some of the next generation of DRLO aircraft being intensively developed in the West; the new radars will be equipped with contoured antenna arrays built into the structure ofthe fuselage and aerodynamic surfaces of the aircraft.

Mainstays have been used by the Russian Air Force at bases in the Kola Peninsula and for observing Allied air operations during the 1991 Gulf War from bases in Ukraine. In 1994 NATO proposed making the E-3 Sentry and the Beriev Mainstay interoperable to enable Russia to provide AEW&C support to future United Nations or coalition operations.

Russia started official testing of its modernized A-50M Mainstay AWACS aircraft for the country's Air Force, a Russian electronics company said 10 September 2007. "The A-50M is the most complex aircraft and we have successfully modernized it," said Vladimir Verba, general director of the Vega Radio Engineering Corp. "The aircraft is undergoing official tests at present and has shown excellent performance so far." The modernization of the A-50M focused on the replacement of outdated analogue equipment with digital electronics systems. "We have greatly improved the processing of the information and significantly decreased the processing time," Verba said.

An operational def1c1ency of the CANDID AWACS comes from its high T-tall conf1guration which interferes w1th radar coverage over a 40-degree sector to the rear of the aircraft. This affects the employment of CANDID AWACS. A sing1e aircraft on station must always maneuver to keep the air battle or threat within the radar coverage area. An "orb1t" cannot therefore be a matter of all right­hand or left-hand turns but instead an "S" pattern with the AWACS always turning toward the threat. For multi-aircraft contiguous patrols, the loss of rear hemisphere coverage means that orbits must be more closely spaced, and perhaps synchronized. Consequently. the CANDID AWACS is better suited for a standoff applicat1on, such as beh1nd the FEBA in a tactical battlefield application, than it 1s for barrier duty, where the threat will be passing through the patrol zone. Other defic1enc1es of the CANDID 1nclude less-than-optimal internal space for equ1pment and crew and lim1ted on-stat1on endurance, estimated to be 6.3 hours unrefueled for an 800-nm-radius mission. Neither enclosures for rest and mental relief, nor a toilet are provided for the 15 crew members, who spend many hours in the air during combat work. At the time when the A-50 was being prepared for series production, there was no choice but to take the 11-76.