v1.0.2 / 01 sep 10 / greg goebel / public domain
* In the 1960s, the Soviet Union developed a jet cargolifter, the "IlyushinIl-76", for military and civil service. The Il-76 proved a great success; itwas the basis for a series of flight refueling tanker, the "Il-78" and"Il-78M", and an airborne warning and control system (AWACS) aircraft, the"A-50". A number of special-purpose variants were also built. This documentprovides a history and description of the Il-76 and its derivatives.
* In 1966, Soviet authorities initiated work on a new four-jet cargolifteraircraft for use with the "Voyenno Trahnsportnaya Aviahtsiya (VTA / MilitaryTransport Aviation)" component of the "Voyenno Vozdoozhnyye Seely (VVS / RedAir Force)" and the Soviet Aeroflot civil airline organization. The newtransport was expected to replace the turboprop Antonov An-12; it wasspecified to have a payload capacity of 40 tonnes (44 tons) and a range of5,000 kilometers (2,700 NMI), with good rough-field capability.
A directive was issued to the Ilyushin OKB (experimental design bureau) fordevelopment of the machine, with the work being performed by a team under OKBchief engineer Genrikh Vasilyevich Novozhilov. It is said this was the firstIlyushin aircraft not built directly under the control of OKB founder SergeiIlyushin; his health was failing and he would retire in 1970. Afterconsideration of various options, go-ahead for full development of the"Il-76" was given in late 1969. A full-scale, if partial, mockup was builtin 1970, with the first prototype built at the OKB's prototype factory inMoscow.
Initial flight of the prototype was on 25 March 1971, with test pilot EduardI. Kuznetsov at the controls. The flight was performed from the secretflight test center at Zukhovskiy near Moscow. The flight lasted an hour,with Kuznetsov giving the machine glowing praise after landing, or so sourcessay -- usually a new aircraft, even a good one, has some quirks to work out,and contrary to common legend, test pilots don't generally walk out after oneflight and praise the machine to the skies. However, it does appear that theIl-76 was a fairly solid machine, since the prototype was flown to France on25 May 1971 to appear at the Le Bourget Air Show near Paris.
The aircraft was described to the press there in a bit of typical Sovietmisinformation as a "purely commercial aircraft", intended for air transportto remote and otherwise inaccessible regions, which was maybe half the truth.NATO assigned the type the codename "Candid", which would become "Candid-A"when another line of Il-76 variants with defensive armament were observed, tobe codenamed "Candid-B".
A static test airframe was then completed, followed by a second flightprototype, which took the air in the spring of 1973, to pay a visit to LeBourget as well. The story about being a "commercial freighter" wasmaintained, though some Soviet officials coyly admitted that the aircraftmight have "military applications". The two prototypes would be retained astest and trials machines; incidentally, they would help set an impressivearray of performance records for the Il-76.
Approval for production was granted, with responsibility for productionfarmed out to State Factory Number 84 in Tashkent, in what is now theindependent nation of Uzbekistan. The plant had previously built An-12s andother transport aircraft, but the Il-76 represented a challenge, since it wasmuch more sophisticated than anything built there before. The obstacles wereovercome and the initial flight of the first production machine on 8 May1973.
Service deliveries for operational evaluation began late in 1973, with theIl-76 reaching full service with the VTA in 1975. All production Il-76swould be built in the Tashkent plant. After the first ten productionmachines were built, the factory switched to an improved "Il-76T"configuration, where "T" stood for "transportniy (transport)". It wasexternally much the same but had an additional fuel tank in the wing centersection and some other small changes. It retained the NATO codename of"Candid-A".
* The general configuration of the Il-76T was so much along the lines of theearlier US Lockheed C-141 Starlifter military transport that it is hard tobelieve Ilyushin engineers didn't find the C-141 an interesting source ofideas. Like the Starlifter, the Il-76T featured a high-mounted swept wingwith anhedral droop and four turbojets on underwing pylons, plus a high swepttee tail. The main landing gear was stowed in large fairings alongside thefuselage to ensure that the cargo bay remained unobstructed. Cargo wasloaded through a rear ramp, with a upward-folding rear door andoutward-folding clamshell doors, all of which were hydraulically actuated.
However, the Il-76T was clearly not a copy of the C-141. Anybody who built afour-jet high-speed cargolifter was likely to come up with a configurationalong such lines, and the resemblance between the two aircraft was no greaterthat, say, between the Messerchmitt Bf-109 and the P-51 Mustang. The twocargolifters were easily distinguished by anyone who could tell one type ofaircraft from another, and the Il-76T had distinctly Soviet features. It wasfitted with glazing under the nose for use by a navigator, handy for gettingmap references and for observing parachute cargo drops. The wing featuredhigh-lift devices to provide short takeoff capability. The landing gear wasclearly designed for rough-field operation, with the nose gear featuring fourwheels in a line-across arrangement, and each main gear assembly featuringtwo rows of four wheels. The end result of the whole was larger and heavierthan the C-141, slightly inferior in payload and range but much superior inrough-field capability.
The wing was fitted with wide-span two-section triple slotted trailing-edgeflaps, as well as full-span leading-edge flaps, which were "nocked out" toclear the engine pylons. There was an aileron on each wingtip and eightspoilers on each wing: four spoilers outboard to provide roll control and"lift dumping" on landing, plus four inboard to provide lift dumping. Thetail control surfaces were conventional, including rudder and elevators.Leading edge flight surfaces were de-iced by engine bleed air.
The Il-76T was powered by Soloviev D-30KP turbofans providing a maximumthrust of 117.7 kN (12,000 kgp / 26,455 lbf) and fitted with bucket-typethrust reversers; normally only the thrust reversers on the outboard engineswere used. The undercarriage also featured hydraulic antilock brakes toreduce landing roll. The nose gear retracted forward and the main gearretracted into the fuselage sponsons, the gear assemblies pivoting 90 degreesso that the axles were parallel to the fuselage, tucked in "sideways" so tospeak. The main gear doors were closed after extending the landing gear toprevent them from being filled with mud or slop in operations off of roughairfields. The tire pressure could be adjusted in flight from 2.5 to 5atmospheres to deal with different types of airfields. There was a turbineauxiliary power unit (APU) in the left landing gear sponson for enginestarting and ground power, with an intake door that was closed in flight tokeep the APU from windmilling.
The cargo hold had a volume of 321 cubic meters (420 cubic yards). It wasfully pressurized and had a titanium floor, with a fold-down roller conveyorsystem and cargo tie-downs in recesses along the edges. There were fourcargo hoists in the roof of the hold to help haul cargoes on board, with thehoists extendable out the rear to allow cargoes to be secured and then hauledin. The tail ramp could be used as lift as well; there was ahydraulically-operated "leg" on the belly of the aircraft forward of thecargo ramp to prevent the aircraft from tipping backwards when the rampleft the ground.
Standard freight modules could be carried. One interesting feature was thatthe aircraft could be quick-converted to a "jetliner" configuration byfitting a set of three modules in the cargo bay. The modules were based onstandard cargo containers; each was 6.1 meters (20 feet) long and 2.4 meters(8 feet) wide and could accommodate 30 passengers, seated four abreast,giving a total passenger load of 120. The modules also provided a galley anda toilet -- it is unclear if only one or all three of the modules had suchfacilities. A similar three-module scheme was used to convert the aircraftinto a flying headquarters / VIP transport.
The cockpit featured an analog layout, typical for the time, and photos showit painted in the usual Soviet turquoise "ergonomic" color scheme. Thewindshield was electrically deiced. There were crew entry doors on each sideof the aircraft parallel to the nose gear, with the doors hydraulicallyactuated to allow opening in flight, when they could be used as slipstreamshields to for parachute jumping. There was an emergency exit hatch on eachside of the fuselage just parallel with the forward wingroot and behind thewing, giving four hatches, plus an escape hatch on the left side of the nosefor the navigator. This hatch was also hydraulically operated to work as aslipstream deflector, the crew diving out down a chute. Apparently nobodytrusted this scheme and it was never used for emergency escape, but the chutewould turn out handy for stashing contraband.
There was also a circular hatch at top behind the cockpit for exit afterditching at sea, and an inflatable life raft stowed behind in thewing-fuselage fairing. There was a prominent radome under the nose for aKoopol navigation radar; since the radome protruded under the bottom line ofthe fuselage to provide coverage to the rear, a special nose-gear tow barwith a kink in it had to be implemented. There was also a weather radar inthe upper nose. ILYUSHIN IL-76T "CANDID-A" _____________________ _________________ _______________________ spec metric english _____________________ _________________ _______________________ wingspan 50.5 meters 165 feet 8 inches wing area 300 sq_meters 3,229 sq_feet length 45.69 meters 152 feet 10 inches height 14.76 meters 48 feet 5 inches empty weight 89,000 kilograms 196,210 pounds max payload weight 40,000 kilograms 88,185 pounds MTO weight 170,000 kilograms 374,780 pounds takeoff field length 850 meters 2,790 feet landing field length 450 meters 1,475 feet max cruise speed 800 KPH 500 MPH / 432 KT service ceiling 15,500 meters 50,850 feet range with max payload 6,660 kilometers 4,140 MI / 3,600 NMI _____________________ _________________ _______________________
The Il-76T was followed in production in the early 1980s by the "Il-76TD",the suffix standing for "transportniy dahlniy (long-range transport)". TheIl-76TD featured uprated Soloviev D-30KP-2 engines providing 122.6 kN (12,500kgp / 27,560 lbf) thrust. It also had enlarged fuel tanks, airframereinforcements to handle higher takeoff weights, and various small changes.It retained the "Candid-A" codename.
* The Il-76/T/TD were labeled as "civil" machines, though in practice theyoften operated in military service and in fact Aeroflot was clearly on thetail end of deliveries. As mentioned, a parallel sequence of strictlymilitary "Candid-B" machines with defensive armament was built as well, withthe parallel nature of the production emphasized by the fact that the secondproduction machine was built to military configuration. This machine wasrolled out in October 1973 and designated the "Il-76M", with the "M"indicating the military nature of the variant.
The defensive armament consisted of a prominent "UKU-9K-502-1" manned tailturret, where "UKU" stood for "unifitseerovannaya kormovaya ustanovka" or"standardized tail installation". This designation was derived from the factthat exactly the same tail turret was fitted to the Tupolev Tu-95MS "Bear"and Tu-22M "Backfire" bombers. The turret's "sting" consisted of twinGryazev-Shipoonov GSh-23 two-barreled 23-millimeter cannon. The GSh-23 wasan ingenious weapon, the two barrels of each cannon being arranged in a"teeter-totter" fashion so that the firing of one barrel hinged the otherbarrel forward to be loaded and fired in turn. The effect was a very highrate of fire, with a cyclic rate of 3,600 rounds per minute.
A PRS-4 Krypton fire-control radar was fitted under the rudder to guide thecannon. Although such defensive armament might have seemed futile, with afighter armed with air-to-air missiles (AAMs) able to easily stand off out ofrange and blow the big transport out of the sky, the cannon also amounted toa countermeasures system, since they could fire chaff and flare rounds toconfuse AAMs. The gunner sat in his own pressurized compartment, generallyentering through a door in the rear cargo bay bulkhead. If he needed to bailout, there was a hydraulically-operated escape hatch on the right side.
Unlike the Candid-A machines, the Candid-B machines were equipped for trooptransport and paratroop dropping, with a row of fold-down seats along eachside of the cargo bay. A double row of seats could also be easily installeddown the center of the cargo bay, and for troop transport an upper deck withseats could be installed as well. Up to 140 troops or 125 paratroops couldbe carried. For paradrops, the cargo bay was depressurized while the cockpitremained pressurized; the jump alarm system was so loud and obnoxious thatparatroopers said they were eager to jump out. The jumpmaster could observeoperations through the nose glazing. The Il-76M could also be fitted forcarriage of stretchers and medical attendants, though this was rarely done.
Some later production Il-76Ms had a defensive countermeasures system,apparently a radar-warning system, with six antennas in small blisterfairings arranged around the aircraft to give 360 degree coverage. Some werealso fitted with an inert gas generator that pressurized the fuel tanks,reducing the chance of an explosion.
* The Il-76M was followed by the "Il-76MD", the suffix meaning "military longrange", which aside from the tail turret was generally similar to theIl-76TD, with the uprated D-30KP-2 turbofans. The Il-76MD had provisions forfitting defensive chaff-flare dispensers to the rear fuselage. Two storespylons could be fitted to each outer wing, for a total of four pylons, eachof which could handle a 500 kilogram (1,100) load. The pylons were rarelyattached; it was troublesome to fit them, since they were heavy and had to beheld up by ground crewmen standing on ladders. Il-76 crews occasionallyperformed practice drops of leaflet canisters, but that's about as much useas was ever made of the pylons.
Demilitarized Il-76M/MDs, with the tail guns and other combat-related gearyanked, sometimes ended up in commercial service. Oddly, some Il-76T/TDswere observed with markings identifying them as Il-76M/MDs despite the lackof a tail turret, while some Il-76M/MDs were observed similarly marked asIl-76T/TDs despite being fitted with the tail turret. These machines aresometimes referred to as "Falsies".
Il-76 export users included Algeria, Cuba, China, India, Iraq, Libya, NorthKorea, and Syria. Most users only obtained a handful of aircraft, but Indiaand Libya obtained 24 each, and Iraq was the big export user, with at least38 delivered. The Indian Air Force (IAF) gave their Il-76MDs the colorfulname of "Gajraj (King Elephant)".
* Once in service, the Il-76 was put into regular use for airlift of suppliesfor the Red military around the Soviet "empire", often flying to bases inEastern Europe and elsewhere. The first major foreign campaign was in late1977, when Aeroflot-marked VTA Il-76s performed an airlift to assist theEthiopian government in its civil war with separatists in the Ogaden andEritrian provinces.
The Il-76 was one of the backbones of Soviet airlift during the war inAfghanistan in the 1980s. It was a difficult mission from the start, theinitial problem being the fact that the Afghan terrain was so high andrugged. On the day of the Soviet invasion, 25 December 1979, an Il-76M raninto a mountain, with all crew lost. Things got worse once the Mujahedin,the Afghan guerrilla movement, got their hands on "man-portable air defense(MANPAD)" missiles. On 26 November 1984, an Il-76M was hit by a capturedStrela-3 (NATO SA-7 Grail) MANPAD, setting off an explosion that ripped theaircraft apart in mid-air. The Strela-3 was not generally regarded as a veryeffective weapon, but in this case the results were all that the Mujahedinmight have hoped for.
Il-76 flights into Afghanistan were then suspended for about a year and halfto figure out how to respond, the conclusion being to fit Il-76s operating inthe theater with twin APP-50 chaff-flare dispensers. The original fit wasinside the rear of the main landing gear sponsons, but the definitive fit wasto scab a dispenser on each side of the rear fuselage. A automateddispensing system was fitted to some Il-76s to dump chaff and flares on amissile launch alarm, but the system had a high false alarm rate and was notadopted for general service. The general procedure was for the tail gunnerto keep a watch out and manually activate the dispensers if a missile waslaunched.
New tactics were evolved, with Il-76s landing and taking off in a tight,steep spiral to make them poorer targets. This procedure caused high levelsof airframe stress, and so the aircraft were often patched with aluminumplates. Mil-26 Hind helicopter gunships guarded the base perimeter to keepMujahedin armed with MANPADs from sneaking in close, and the gunship crewswere also ordered to soak up MANPADs to keep them from hitting a transport.By that time, the Mujahedin were being equipped by the US with the StingerMANPAD missile, which was much more effective than the Strela-3; every nowand then a Hind had to take a Stinger hit.
Soviet forces left Afghanistan in early 1989, but the Soviet-backedgovernment managed to hang on until 1992, and in the meantime Il-76scontinued to fly into the country. An Il-76MD was lost on 27 March 1990 onapproach into Kabul, though the problem was clearly pilot error, not hostileaction. On 6 June 1990, an Il-76MD loaded with fuel was hit by a Stinger;the pilot made a wheels-up landing but the aircraft was a writeoff.
In the last days of the Soviet-backed government, Il-76s were used to pullout Soviet personnel, with an Il-76MD destroyed on the ground by artillery on28 August 1992. The crew survived, to be snatched up by another Il-76MD thatmanaged to get off the runway with its mainwheel tires shot to pieces. Theaircraft that was destroyed in the incident seems to have been unlucky; inthe summer of 1988, it had been hit by a Stinger while flying an airliftmission in support of the pro-Soviet government of Angola in Africa, losingan engine but landing safely.
* Even the replacement of the Soviet-backed government and the rise of theMuslim-fundamentalist Taliban didn't quite end the adventures of the Il-76 inAfghanistan. On 3 August 1995, a MiG-19S fighter operated by the Talibangovernment intercepted an Il-76TD operated by the Russian airline Airstan andforced it to land in Kandahar. Taliban officials were annoyed at Russianbacking of anti-Taliban Afghan forces and wanted to use the crew as hostagesfor the return of Taliban members believed to be held by the Russians. TheRussian government negotiated to no effect; a scheme to perform a commandoraid to free the hostages was dismissed as impractical.
However, the crew was resourceful enough to rescue themselves. They managedto talk their captors into giving them access to the Il-76TD in order to keepit in flightworthy condition, and on 16 August 1996, after over a year incaptivity, they made a run for it, taking off with three of their guardsalong with them, and flying at low level to Iran with a huge cloud of dust inthe aircraft's wake. Fighters were scrambled to intercept, but the pilotsassumed that the aircraft was heading north to Russia and failed to stop theescape.
* The Il-76 was seeing action in various ways elsewhere. On 23 September1980, just after the start of the Iran-Iraq War, an Iraqi Il-76 in civilcolors was coming into Baghdad just at the very time Iranian McDonnell F-4Phantoms happened to pass through on a raid. The Il-76 was a tempting targetand was promptly shot down, crashing just beyond the airport runway.
During the 1980s, the US Reagan Administration had a protracted feud withLibyan dictator Mohamar Qaddafi, which reached a peak in early 1986 whenLibyan agents were implicated in a plot to bomb a disco club in Berlin thatkilled a US soldier. On 15 April 1986, the Americans conducted a large-scaleair strike against Libya codenamed Operation EL DORADO CANYON. One of thevictims was a Libyan Arab Airlines Il-76T that was caught on the ground, withwitnesses saying the aircraft ended up so full of holes that it looked like asieve. The Il-76 was only a part of a long list of casualties, and Qaddafiwas suitably intimidated.
* The Il-76 was a witness to the post-Cold War world, helping withdrawRussian forces from Eastern Europe in the early 1990s. During the troublesin what was once Yugoslavia, Russian and Ukrainian Il-76s, often painted inwhite United Nations colors, often flew into Sarajevo on humanitarianflights. One overshot the runway on 31 December 1994, suffering some damagebut with no harm to the crew, but sniper activity made recovery of theaircraft impossible and it was abandoned. Il-76s have also been used onhumanitarian missions in Africa.
The Il-76 has a good safety record but has been in its share of accidents.On 12 December 1995, an Il-76MD operating in support of the Rooskiye Vityazi(Russian Knights) flight demonstration team was leading the team's SukhoiSu-27s back from a tour in Malaysia, with a stop planned at Cam Ranh Bay inVietnam, an American-built facility that the Russians had taken over. Thelanding system at the airfield there was in poor shape and the sky was sockedin; the Il-76MD came in too low, and though the pilot caught the error andpulled up, three Su-27s flew into the ground. The Il-76MD pilot wascourt-martialed and sentenced to six years in prison, but was granted amnestybecause of his good past service record.
In one of the worst accidents in aviation history, on 12 November 1996 aKazakhstan Airlines Il-76TD collided with a Saudi Arabian Airlines Boeing 747jumbo jet on approach to New Delhi. All 39 on board the Il-76TD were killed;astoundingly, two of the 312 on the 747 survived.
* By the time of the fall of the USSR, about 700 Il-76s had been built. Thetype continues to be produced in Tashkent, and remains in extensive servicein Russia, former Soviet republics, India, and elsewhere -- with Iranacquiring a small fleet when Iraqi Il-76s were impounded after a mass"defection" of Iraqi Air Force aircraft during the Gulf War.
In fact, an improved version, the "Il-76MF", was promoted after the fall ofthe USSR. The US Air Force had found that their C-141A Starlifter often ranout of storage volume before it ran out of lift capacity, and so Lockheeddeveloped the stretched C-141B upgrade to permit more cargo volume. Planswere made for a stretched Il-76 early in the program, but such schemesfaltered on the non-availability of an engine adequate to lift the heavierairframe: the D-30KP series had simply run out of steam for furtheruprating.
In the 1980s, however, the Soloviev OKB developed a next-generation turbofan,the PS-90 series, for the Tupolev Tu-204 twinjet airliner. In the 1990s, thestretched Il-76 concept was revived, with the aircraft to use the improvedSoloviev engines. A model was exhibited at the Moscow AeroShow in 1992, withthe initial prototype performing its first flight on 1 August 1995, with testpilot Anatoliy V. Knyshov at the controls.
The Il-76MF featured a 3.3 meter (10 foot 9 inch) fuselage plug installedfore and aft of the wings, giving a total stretch of 6.6 meters. The stretchmeant higher capacity for troopship operations, so the number of emergencyexits on each side of the fuselage was increased from two to four. The fourPS-90A turbofans provided 157 kN (16,000 kgp / 35280 lbf) thrust each; theywere not only about 28% more powerful than the D-30KP-2 turbofans theyreplaced, but had 15% better specific fuel consumption, lower noise, andlower emissions. They also featured cowling thrust reversers instead of thebucket reversers of the D-30KP series.
Maximum payload weight went from 40 to 60 tonnes, demanding wingreinforcement. The wing configuration was otherwise not changed and therewas no major revision to the landing gear either. Avionics were upgradedoverall, including a "glass cockpit" with color flat-panel displays, anupgraded Koopol-3 navigation radar, and new communications gear. A newTA-12-60 APU was fitted as well. Although the "MF" suffix suggested amilitary transport, there was no tail turret. ILYUSHIN IL-76MF: _____________________ _________________ _______________________ spec metric english _____________________ _________________ _______________________ wingspan 50.5 meters 165 feet 8 inches wing area 300 sq_meters 3,229 sq_feet length 53.2 meters 174 feet 6 inches height 14.76 meters 48 feet 5 inches max payload weight 60,000 kilograms 123,300 pounds MTO weight 210,000 kilograms 463,050 pounds max cruise speed 850 KPH 530 MPH / 460 KT range with max payload 6,300 kilometers 3,915 MI / 3,400 NMI _____________________ _________________ _______________________
There were reliability problems with the PS-90A engines at first, requiringthem to be derated for a time, but the troubles were resolved. Although theVVS has evaluated and formally adopted the Il-76MF, the exact number ofIl-76MFs built to this time is unclear. Jordan purchased two in 2005, makingthat country the first foreign user of the variant. Commentaries in theWestern aviation press suggested the Jordanians got a pretty good deal,pointing out that the Il-76MF had about three-quarters of the lift capacityof the modern Boeing C-17, range equal to the C-17, but about a quarter ofthe flyaway cost. How operating costs compare is hard to say:Soviet-Russian gear has a reputation for a certain crudity, but it is alsooften very rugged, reliable, and easy to maintain.
The Russian Air Force is very reliant on the Il-76MD and wants to keep theirmachine in service, with an upgrade program in the works to refit theexisting machines with PS-90A engines and the improved avionics of theIl-76MF. The upgraded machines are to be designated as "Il-76MD-90"; somenew-build aircraft with a similar or the same configuration are also underconsideration, with these machines sometimes referred to as "Il-476".
* There were a number of specialized Il-76 subvariants. In the 1980s, fourIl-76MDs were modified to a specialized "standoff jammer" configuration,designated the "Il-76PP", where "PP" stood for "postanovschchik pomekh"or "ECM aircraft". They carries the Landysh (lily) countermeasures system,being decorated with blade antennas, small antenna fairings, wingtip antennapods, and two oversized "cheek" fairings forward of and merging into thelanding gear sponsons. Each cheek fairing contained an Ivchenko Al-24VTauxiliary power turbine to provide power for the Landysh system, with eachAPU providing 2,100 kW (2,820 SHP) and driving four electrical generators.
The IL-76's original APU had to be moved back in the left landing gearsponson and fed by an "elephant ear" intake. The main passenger doors had tobe modified to fit around the cheek fairings, and the forward emergency exitswere deleted. A cooling system drew in air from inlets on the front of thelanding gear sponsons, with the air exiting through an exhaust in the cargobay doors. The Beriev OKB performed the modifications.
These aircraft were referred to as "Chipmunks" because of the cheek fairings.The concept was not successful, the Landysh system being unreliable as wellas a power hog, and the platform suffered from electromagnetic compatibilityproblems -- always an issue with a high-powered jammer system, since suchthings have a nasty tendency to jam themselves. Although the Chipmunks wereextensively evaluated, they never went into service.
* Two Il-76s were built in the mid-1980s as flying command post /communications relay aircraft and designated "Il-76VKP", where "VKP" stoodfor "vozdooshniy komanndniy poonkt (airborne command post)". The noseglazing was faired over and a long "canoe" fairing for a satellitecommunications antenna was fitted over the top of the aircraft from thecockpit back to the wing fairing. Various antennas littered the fuselage,including a large blade antenna on each side of the tail. The forwardsection of the maingear sponsons was swollen, and a long antenna could bespooled out from the aircraft to perform very low frequency (VLF)communications with Soviet ballistic missile submarines. The Il-76VKPs wereclearly the Soviet answer to the US "Take Command And Move Out (TACAMO)"aircraft, intended to support Soviet strategic nuclear forces in a crisis.
* Beginning in the late 1970s, a total of five Il-76s was converted for useas engine testbeds and designated "Il-76LL", the "LL" standing for"letauschchaya laboritoriya (flying laboratory)", a suffix commonly given toSoviet test and trials machines. They were fitted with engineeringworkstations and a modified electrical system to provide power for the testgear, and generally had twin heat exchangers on the left fuselage behind thewing. In most pictures of Il-76LLs, the engine under test was mounted on theleft inboard engine pylon. The Il-76LLs tested a wide range of engines,including turboprops, propfans, and turbofans, such as the big Lotarev D-18Thigh-bypass turbofan.
A number of Il-76s were used as avionics testbeds, but these were mostlyinvolved in secret military projects and not much is known about them; infact it's hard to determine if they were actually given the designation of"Il-76LL". One was used as a testbed for a side-looking radar system,featuring distinctive antenna fairings on the fuselage forward of the wing,first flying in 1988. It also had other systems, including an infraredscanner, and was sometimes used for land surveys. Other Il-76s were used totest electronic intelligence (ELINT) gear or systems for the A-50 "Mainstay"AWACS, described below.
One of the most distinctive, if highly secret, of the Il-76 testbeds was the"A-60", a testbed for an airborne laser system developed in response to theUS "Star Wars" missile-defense effort of the 1980s. The A-60 was developedin conjunction with the Beriev OKB and featured a prominent nose radome,clearly for a targeting radar system; a pop-up turret on the rear spine forthe laser; and big "cheek" fairings like those of the Il-76PP standoff jammeraircraft for auxiliary power turbines, clearly to power the laser.
* Other minor variants and modifications included:
A number of variants were considered but not built, including a drone carrierand controller platform; and a spacelaunch booster carrier, with the boostercarried on a dorsal rack.
* The Soviets had some problems getting organized on inflight refueling. Itdoesn't appear to have been generally that big of a technical challenge, thedifficulties being mostly due to the fact that they had less strategic needfor inflight refueling, and other priorities kept bumping acquisition of atanker fleet down the queue. The VVS did acquire numbers of Tupolev Tu-16N"Badger" and Myasischchev 3MS2/3MN2 "Bison" tankers in the 1960s, but theseaircraft were only capable of single-point refueling, and by the 1970ssomething a bit more capable was clearly required.
There were plans early on to use the Il-76 as a tanker, but the initialversions didn't have the lift capacity to do the job. The development of theuprated Il-76MD made a tanker variant more attractive, leading toauthorization of a development program. The sole "Il-78" tanker prototypeperformed its initial flight on 26 June 1983, with OKB test pilot V.S.Belousov at the controls. The variant proved satisfactory, leading tointroduction to VVS service in 1987. The type was given the NATO codename of"Midas".
The Il-78 tanker featured three hose-drum units (HDUs), with one under eachwing and one on a stub pylon on the left side of the tail. The HDUs werebuilt by the Zvezda organization and designated "UPAZ-1", where "UPAZ" stoodfor "unifitseerovanniy podvesnoy agregaht zahprahvki" or "standard suspended[external] refueling unit". The UPAZ-1 was basically a stock item that couldalso be carried by tactical aircraft for buddy tanker operations. Each HDUwas in the form of a square-section pod with a conical nose. The nose coneretracted inward to admit airflow to drive a ram-air turbine for the fuelpump, and there were red-green-yellow "traffic lights" on the rear of the podto communicate with pilots of client aircraft. The HDUs had a high fuel flowrate of 2,500 liters per minute (660 US gallons per minute).
The HDUs could be easily detached, and Il-78s have been observed with thewing HDUs removed. The tail HDU installation looked like a clearimprovisation, but it permitted installation of a centerline refueling pointwithout demanding major structural changes to the aircraft. Early productionfeatured the centerline pod mounted directly on the rear stub wing, but laterproduction featured the pod hung off a pylon beneath the stub wing --apparently to reduce the effects of turbulence on the refueling hose.
Although the UPAZ-1 HDUs could draw fuel from the aircraft's fuel system, twolarge fuel tanks could be pallet-mounted inside the aircraft's cargo bay tosupport tanker operations. A fuel dump system was fitted to the aircraft toallow the tanks to be drained in case of an emergency. The cargo-bay fueltanks could be pulled to allow the aircraft to be used in the transport role.While the HDUs were controlled from the cockpit by the flight engineer, thetail cannon position was used as an observing post, with another "trafficlight" array on the back of the turret where the cannon used to be, plusperiscopes under the position staring forward to allow the observer to keepan eye on the HDUs. The aircraft was fitted with a transponder to helpclients find it.
The Il-78 was followed by a dedicated tanker variant, the "Il-78M", whichcould not be used as cargolifter. The Il-78M had three cargo-bay fuel tanksinstead of two, and the rear cargo doors were replaced by a fixed fairing.All had the stub wing / pylon mounting scheme for the centerline HDU. TheIl-78M retained the "Midas" NATO codename, though some sources haveidentified the Il-78 as the "Midas-A" and the Il-78M as the "Midas-B".
* The Il-78/78M remains an important asset in Russian service. None wereexported as such, but the Iraqis modified a single Candid-B to a tankerconfiguration late in the 1980s, with a single HDU fitted to a pylon hangingthrough the centerline of the cargo doors. The HDU was a Douglas unit thathad been supplied by the French for carriage by Iraqi Mirage F1s. Thismachine was a clear improvisation; its ultimate fate is unknown.
The Indian Air Force (IAF) has obtained an Il-76-based tanker fleet, theaircraft being designated "Il-78MKI", with the first obtained in 2003. Theyweren't stock Il-78 or 78M machines; they were originally Il-76s obtainedfrom Uzbekistan and refurbished, then being fitted with Israeli tankermodules and French avionics. They have been used to support IAF exercises asfar afield as Alaska.
* As with tankers, the Soviets were laggards in adopting "airborne warningand control system (AWACS)" aircraft -- platforms carrying wide-areasurveillance radar and other electronics gear to detect enemy aircraft andother assets, then vector combat assets against them. In the 1960s the USSRfielded an AWACS aircraft, the "Tu-126 Moss", based on the Tu-114four-turboprop airliner, itself based on the "Tu-95 Bear" bomber.
In the 1970s, the Soviets began development of an improved AWACS based on theIl-76. The result, the "A-50", was apparently introduced to service in 1984.It was developed in cooperation with the Beriev organization. It wasassigned the NATO codename of "Mainstay".
The A-50 was organized around the Shmel (Bumblebee) surveillance system, thecore of which was a pulse-Doppler radar with a rotating antenna dome on theback behind the wings, known as a "pogahnka (toadstool)" to crews. The Shmelsystem also included identification friend or foe (IFF) capabilities and anumber of color workstations, with datalinks, including satellite links,providing communications with fighters and other assets, and a missioncomputer coordinating the whole. The aircraft was littered with otherantennas, most prominently in the form of an antenna fairing on the back justforward of the wings, and a finlike antenna on the rear of each landing gearfairing.
The nose glazing of the Il-76 was deleted, replaced with an extended antennafairing under the nose and a single small window on each side; the tailturret structure was retained, but used to accommodate electronic systemsinstead of cannon. The A-50 was fitted with an inflight refueling probe, butreports indicate that the interaction of the slipstream of a tanker with theA-50's radome created such nasty buffeting that inflight refuelingdemanded special pilot qualification.
The A-50's Shmel radar was not in the same league as that of its Westerncounterpart, the Boeing E-3 Sentry, lacking the same range or ability totrack as many targets simultaneously; the Russians did claim the system hasgood "look down" capability, able to pick out low-flying targets in "groundclutter". Exercises demonstrated the ability of the A-50 to direct MiG-31"Foxhound" interceptors, Tu-22M-3 "Backfire" bombers, and submarinessimultaneously.
Aside from the flight crew, the A-50 carried ten systems operators. Theavionics kit was heavy -- the Soviets were generally competitive with theWest in terms of airframe design, but their electronics capabilities weredistinctly inferior -- and apparently the A-50 suffered badly from weightgrowth during its development. Its aircrew facilities were said to becramped, noisy, and lacking in amenities, one particularly troublesomeomission being no relief-crew bunks. The old Tu-126 Moss, derived from alarge airliner, was much more comfortable, and an A-50 is apparently has notbeen a desired crew assignment.
During the 1991 Gulf War, two A-50s were kept on station over the Black Seato observe Coalition air activities over Turkey and northern Iraq. The A-50remains in service.
* The Soviets developed another Il-76 variant that looked something like theA-50, but was intended for an entirely different mission. The Soviets hadlong used modified Ilyushin Il-18 turboprops rigged with electronic gear tomonitor the telemetry from missile and space launches. When these machineswere finally retired, two Candid-Bs were converted to a similarconfiguration, with an antenna dome on the tail and various antennas litteredover the airframe. These machines were simply known as "Aircraft 676" and"Aircraft 776".
Following this exercise, the Soviets decided to modify five Il-76MDs to amore capable tracking and telemetry configuration, also with a litter ofantennas but this time including the Shmel "toadstool" radome. Thesemachines were designated "Aircraft 976", or "SKIP" for "samolyotniy komahndnoismereetelniy poonkt (airborne measurement and control station)". They werealso referred to as "Il-76SK", "Il-976", or "Be-976", the Beriev OKB havingbeen involved in the conversion.
Although some sources incorrectly identified the Aircraft 976 aircraft asAWACS platforms, the similarity of these machines to the A-50 was somewhatsuperficial, effectively limited to the Shmel radome. They had nose glazing,cargo doors, and a tail turret station, though the cannon were yanked andreplaced with an antenna fairing. They were fitted with wingtip pods, likethose of the Il-76PP Chipmunks, and also with a set of L-shaped antennas oneach side of the tailfin. They did not have the vent in the tailfinextension. They appeared in Aeroflot colors, though they were clearly notcivil machines.
* The Iraqis modified a few Il-76s to AWACS configurations in the 1980s. Thefirst was the "Baghdad-1", which was a clear improvisation, with a FrenchThomson-CSF Tigre surveillance radar installed in the cargo bay of a Candid-Aand the radar antenna fitted in a fixed composite radome replacing the cargodoors. It was use operationally late in the Iran-Iraq War. There's noinformation on how well it worked, but it was dubious in appearance.
The second was the "Baghdad-2", which had the Tigre radar in a conventionaldorsal radome like that of the A-50's Shmel radar. It was actually notreally an AWACS, instead being strictly a radar picket aircraft; theBaghdad-1 had fighter control links, but the Baghdad-2 did not. There werelong strakes along the rear fuselage to compensate aerodynamically for theradome. Two conversions of Candid-As were performed, to be named "Adnan-1"and "Adnan-2" after an Iraqi general who had been killed in an air accident.These aircraft were said to have performed operational service late in the1991 Gulf War. Their ultimate fate is unclear.
* Although the Baghdad conversions were unsophisticated compared to the A-50,the Indian Air Force has obtained Il-76-based AWACS platforms that are wellin advance of the A-50. These machines are fitted with the Israeli AircraftIndustries (IAI) Phalcon radar and control system. The Phalcon system is anL-band radar with a fixed phased-array antenna using electronic steering. Itis regarded as state of the art, well superior to Soviet-Russian radarsystems. The IAF Il-76 / Phalcon systems are fitted with eight multifunctionoperator consoles with large-screen color flat-panel displays, and twoelectronic countermeasures / electronic intelligence operator stations.
All these machines were upgraded from used Il-76 airframes. The deal was cutin 2004, with initial delivery in 2008 and delivery of the three completed in2009. The IAF has a follow-on batch of three more on order.
* Sources include:
* Revision history: v1.0.0 / 01 nov 06 / gvg v1.0.1 / 01 nov 08 / gvg / Minor cosmetic update. v1.0.2 / 01 sep 10 / gvg / Minor cosmetic update.
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