|Last Updated: Mon Jan 27 11:18:09 UTC 2014|
Of all of the descendants of the Boeing B-29, the Tupolev Bear is the most remarkable. The Bear is a mainstay of Russia's strategic aviation forces and a key element in Russian naval strategy, being currently in production to support at least one of these roles. The new Bear H is Russia's first cruise missile carrier and as such has led the United States to deploy an immense network of Over-The Horizon (OTH) radars, quite a feat for a design of the Bear's age.
The origin of the Bear may be traced back to 1945, when several USAAF B-29 aircraft, severely damaged by Japanese defences, landed in Russian territory. While the crews were repatriated, the B-29s never left Siberia. Engineers from the Tupolev and Shvetsov bureaus, despatched from their plants, proceeded to strip the aircraft down to the last component, analysing and documenting all.
In 1945, Russian bomber design was at its worst for decades, the only production four engined bomber being of prewar design and hopelessly inadequate in comparison with the USAF's B-29 fleet. Russia needed a capable bomber to project its newly acqui red nuclear capability and copying the B-29 was the least painful way of getting one. It is to the credit of the robust B-29 that it could be successfully produced in an industrial infrastructure as obsolete as that of the USSR in 1949.
Hailed as a fully Soviet design, the Tu-4 Bull first flew in 1947 and entered series production in 1949, 1200 were eventually built. The Russians copied the airframe, powerplants, systems and the unique fire control system which remotely controlled the four gun turrets. The notable difference between the aircraft was in the Russian installation of NS-23 cannon in preference to the 50 calibre guns of the B-29.
While the Tu-4 provided Russia with a credible nuclear strike force, the US deployment of the B-50, B-36 and B-47 made it quite apparent that a more capable aircraft was required. The Tupolev bureau developed the Tu-4 design into the larger Tu-80 and Tu-85, eventually adopting the characteristic glazed nose and stepped forward fuselage used to this date.
Neither of these aircraft was considered successful and the Russians turned to their newly developed turbojets and turboprops, thus spawning two major families of aircraft - the Badger and the Bear.
The Tupolev Tu-95
The Badger and the Bear were both evolutionary and revolutionary in Russian aircraft design. The evolutionary aspect was in the design of the fuselage and systems, which directly illustrated their Boeing heritage. The revolutionary aspect was in the application of a swept wing and turbine powerplants.
The Tu-95 was designed in 1951/52 and first flew in 1955. The fuselage of the Tu-95 resembles that of the B-29 in many respects, it is circular in cross-section, with a pressurised shell fore of the wings, has substantial structure to support the thick wing roots below and behind which is situated a weapon bay. The fuselage behind the wing retains the general configuration of its ancestor, although it appears that only a single pressurised shell is used in most versions, below the vertical stabiliser; this contains the aft gunner/operators' stations. The tailplane is raised somewhat above the fuselage and a tail gunner's station is situated at the end of the fuselage. Unlike the B-29 with gunners stationed just aft of the wing, the Tu-95 gunner(s) have two large observation blisters below the tailplane. The Tu-95 did however retain part of the remotely controlled gun turret system of the Tu-4, with a retractable dorsal and a ventral barbette each containing a pair of 23mm NR-23 cannon.
The glazed nose of the aircraft housed the navigator/bombardier's station and is followed by a conventional flight deck with dual controls. The forward fuselage almost certainly houses additional stations for systems operators (eg. attack radar in later derivatives), a gunner and possibly a mission commander or political officer (this would not be a unique strategy, Japanese bombers such as the Betty carried a commanders' seat just aft and slightly above the pilots' stations and in view of the high degree of KGB control over nuclear systems during the 1950s and 1960s would almost seem the natural solution). The fuselage weapon bay is situated below and aft of the wing roots, it could fit several high yield nuclear devices. It is not clear whether the fuselage tunnel connecting the forward and rear pressurised areas as used in the Tu-4 was retained, although it would have made some sense given the expected duration of sorties.
Access to the rear pressurised area is almost certainly via a ventral hatch (cf Badger), visible on some photographs.
The Tu-95's wing and powerplant were a radical departure from its predecessors. The large swept wing with four pairs of fences carried four large engine nacelles inboard and outboard Fowler flaps and conventional ailerons. Its thickness and area provided considerable volume for fuel, the noticeable anhedral on the ground disappears under flight loading. The inboard nacelles end in large trailing edge pods which conceal the main undercarriage. This arrangement offers a wide track for stability, frees fuselage/centre section area for payload and doesn't penalise the wing structure with the need for undercarriage wells.
These attributes were so important to the Tupolev bureau that this configuration became its trademark.
The powerplants, four huge 12,000 shp Kuznyetzov NK-12 turboprops driving counter-rotating four bladed AV-60 propellers, typify Russian design philosophy - simplicity, size and attain ment of performance through brute force. At the Tu-95's dash speed of 0.87 Mach these props are supersonic well before the tips and certainly are not operating at peak efficiency. Nevertheless this configuration offered superior payload/range to the turbojets of the day without an unreasonable penalty in cruise speed and this view no doubt prevails to this day. In 1955 the speed and strike radius were adequate to defeat many Western all weather air defence fighters.
One of the interesting side effects of the Tu-95's powerplant arrangement is an incredible prop noise level, even at cruise speed the blade tips are mildly supersonic in spite of the low speed on the 750 rpm props. One can have no doubt that prop harmonics must exact a solid penalty in vibration induced failures of onboard electronic systems.
Photographed off the Cocos islands by an RAAF P-3C is a long-range maritime patrol and ASW aircraft. The AV-MF is believed to operate about four dozen of these aircraft.
Another side effect of considerable importance today is the tremendous radar cross-section of the whirling props, particularly from the frontal aspect. Not only increasing the detection range of the aircraft, the props also modulate the return and thus can betray the aircraft's identity to an appropriately built radar system.
The Tu-95, often designated Tu-20, entered service with the Dal'naya Aviatsia (DA - Long Range Aviation) of the Soviet VVS (Air Force) in 1955, making its public debut in the 1955 Aviation Day flypast. While many Western analysts didn't consider the Tu-95 a serious competitor to the turbojet powered Myasishchev M-4, unveiled a year earlier, Soviet air strategists clearly preferred the Tupolev for its superior range and more adaptable configuration. The Myasishchev M-4 Bison today serves primarily as a tanker.
While early derivatives of the Tu-95 designated by NATO as Bear served as strategic nuclear strike aircraft, the airframe was further developed as a passenger transport. The fuselage of the new Tu-114 Cleat had a larger diameter than that of the Bear and employed a low wing rather than mid wing configuration.
It achieved little success as an airliner but did provide an airframe design for the Tu-126 Moss Airborne Early Warning system. The Moss attained IOC in 1970, with a single aircraft deployed to India in 1971 in support of Indian air operations against Pakistan in the war over Bangladesh. The Flat Jack AEW radar of the Moss has been credited with very poor overland lookdown performance and this limitation in capability may well be the reason for the Russians having only ever deployed about a dozen of this type. It is now being replaced with the new Il-76 Mainstay system.
Ultimately, the deployment of the missile armed century series fighters and the new Surface-to-Air-Missile (SAM) systems led to the demise of the Bear as a strategic penetrator. It also marked the beginning of an evolutionary path perhaps unique in aviation history, a front line strategic combat aircraft maintained in production for over three decades. No less than nine distinct versions of this aircraft exist with many further subtypes of which at least one may still be in series production.
The Bear A was the initial nuclear strike version of the Tu-95, with a glazed nose, chin mounted nav/attack radar and internally carried free fall nuclear bombs. Given the state of Soviet electronic warfare capability in the mid fifties, this aircraft relied heavily on its six NR-23 cannon if threatened by interceptors in the aft hemisphere. Given the fundamental limitations of this weapon system it was soon supplanted by the Bear B.
The Bear B was a dedicated long-range missile carrier, armed with the massive AS-3 Kangaroo strategic nuclear standoff missile. The Kangaroo was a substantial weapon and was derived from the Su-7 Fitter airframe. As such it weighed about 25,000 lb at launch, of which 5,000 lb was a large thermonuclear device.
The Kangaroo was probably powered by an Al-7F afterburning turbojet like the Fitter, with which it shares wing and fuselage structure. The Bear B carried its Kangaroo recessed in a ventral bay. A fairing covered the Kangaroo's inlet and almost certainly covered the high pressure air starter system which would have been used for the turbojet. Bear B located its targets with a large Crown Drum I-band nav/attack radar which occupied most of the spacious nose. After launching the Kangaroo the Bear provided guidance for the missile.
Some sources suggest the initial use of beam riding guidance followed by datalink midcourse updates, although given the mission profile it is very likely that the Kangaroo carried a simple beacon transponder and was steered onto its target by an operator, a simple autopilot maintaining heading and attitude. An A-336Z or 346Z datalink was attributed to the Kangaroo midcourse guidance system. The Kangaroo would be launched at about 40,000 ft from where it would climb to about 60,000 ft at 1.6 Mach and then enter a shallow 1.8 Mach dive onto its target, which it would obliterate with its large thermonuclear warhead. Maximum range was estimated as of the order of 350 nm.
The Bear B carried a tail warning and gunlaying radar below the rudder, this may have been a Bee Hind although the Box Tail is usually attributed to later versions of the type. The six NR-23 guns were also retained. At a later stage these aircraft acquired the Sirena II and III Radar Homing and Warning (RHAW) equipments and the standard SRO-2 Identification Friend Foe (IFF) systems. Navaids included the A322Z Doppler system and the RSBN-2 short-range navigation system.
The Bear B entered service in the early sixties, the DA eventu ally acquiring about 50 aircraft. Some have apparently been used in the Maritime Reconnaissance role, with inflight refuelling probes fitted and a large fairing on the aft starboard fuselage.
A Bear D photographed by RAF Phantoms over the North Sea in 1973. The D version was primarily used as an intermediate launch station monitoring aircraft which provided accurate guidance data for anti-ship cruise missiles.
The Bear C was first seen in 1964 shadowing Allied shipping. This aircraft was a Kangaroo capable strike version with additional blister fairings on the aft fuselage, almost certainly housing Electronic Support Measures (ESM) antennas.
Some Bear C aircraft had their tail turrets deleted and replaced with a streamlined tailcone fairing, also housing electronic hardware.
Bear C retained the Crown Drum attack radar and was often designated together with the Bear B as the Bear B/C in view of their similarity.
First sighted in 1967, the Bear D is a major version and one of the most important types in the Russian Aviatsia Voenno Morskovo Flota (AVMF-Soviet Fleet Air Arm) MR force. While it retains the glazed nose of the Bear A it also carries the small chin radome of the I-band Puff Ball nav/attack radar, an inflight refuel ling probe and its distinguishing feature, the huge ventral radome associated with the powerful I/J-band Big Bulge surface search and targeting radar. The Bear D retains the fuselage antenna blisters of the MR/Strike Bear C but has additional ESM fairings on the tips of its tailplane.
The defensive suite includes the Box Tail fire control radar with the ventral barbette and tail turret retained as in earlier aircraft. In some later aircraft the tail gunner's station is replaced with a tailcone similar to that on some Bear C aircraft.
Bear D carries no offensive weapons but serves as an Over The-Horizon (OTH) targeting platform for ship/sub launched Surface-Surface Missiles (SSM), certainly relaying target positions and very likely also providing midcourse guidance for SSMs such as the 200nm class SS-N-3A/B Shaddock and possibly the newer sub launched 300nm class SS-N-12.
The AV-MF employ 45 of this aircraft which has been reported as being based at the Cam Ranh Bay airbase in Vietnam.
The Bear E is a long-range recce version of which few were apparently built. Its airframe is that of a Bear A with an inflight refuelling probe, rear fuselage blisters and a sensor pallet in the bomb bay.
Tu-142 Bear F
The Tu-142 is another AV-MF version. It entered service around 1970 and is tasked with long-range Anti Submarine War fare (ASW) patrol and Maritime Reconnaissance (MR). Bear F is also a major version and its production was resumed as late as in the 1980s, while the basic type has been through various system upgrades.
The fuselage of the late model (mod 2, 3, 4) Tu-142M Bear F is mission oriented with an A style but lengthened forward fuselage with a glazed nose and chin radome as on some Bear Ds, inflight refuelling probe, increased windscreen depth and bulged nose wheel doors. The ventral radome of the surface search radar (possibly a derivative of the Big Bulge) was shifted forward to allow stores carriage in the main weapon bay, these include torpedoes and depth charges of various types. The ventral and dorsal barbettes were removed from the aircraft to provide space for a sonobuoy dispenser bay. Many Bear F aircraft also carry a Magnetic Anomaly Detector (MAD) boom at the top of the vertical stabiliser. Many earlier aircraft also had enlarged inboard engine nacelles but this was later abandoned.
The Tu-142 like all later versions of the Bear is fitted with the 14,795 shp NK-12MV turboprop which offers a dash speed of about 500kt at 40,000 ft and an unrefuelled combat radius of 4,475nm. Approximately 55 of this version are in AV-MF service and the type is apparently stationed at Cam Ranh Bay.
The Bear G is the designation of a recent retrofit to older Bear B/C aircraft. Like its predecessors the Bear G is a long-range missile carrier, it is armed with a pair of very potent AS-4 Kitchen missiles. The Bear G carries an inflight refuelling probe and retains the distinctive radome of the Crown Drum attack radar, housing a new Down Beat nav/attack radar common to the Backfire/AS-4. This suggests the use of the Backfire's fire control and nav/attack systems.
An additional small radome is situated just beneath the refuelling probe, its purpose is unclear although it could belong to weather/nav radar or a high power ECM antenna (cf B-52G). Bear G is fitted with a tailcone fairing similar to some Bear Ds but retains the ventral barbette and its associated observation blisters. The rear fuselage ESM blisters are further supplemented with additional radomes above and below the new tail section, these are very probably associated with ECM systems.
One analyst is quoted as having associated the tailcone with a large trailing VLF antenna (cf Tacamo) but this seems inconsistent with the aircraft's strike role.
The Tu-126 Moss is essentially a Tu-114 Cleat airframe, developed in turn from the Bear and fitted with an airborne early warning radar system. The Moss proved a failure in service and only about a dozen were ever built, its role nowadays being taken over by the more capable Mainstay derivative of the 11-76 Candid.
This table was compiled from various sources and items such as weights, performance and equipment fit should be treated with caution. Many sources attribute the Bee Hind fire control radar to Bear Bee Hind was carried by early versions but was superceded by the larger Box Tail equipment. Late model Bear F and Bear H may carry newer generation systems although at this stage nothing has been published in the open literature (Author).
Bear G is tasked with long-range strike and can carry both anti-shipping and nuclear versions of the AS-4 Kitchen on its two wing root and one fuselage stations. The 14,3301b liquid propellant rocket powered Kitchen was first deployed in the sixties and was carried on Blinder and Backfire aircraft much like the RAF's somewhat smaller Hawker Siddeley Blue Steel on Vulcans and Victors.
It carries a 2,000 lb warhead which may be conventional or nuclear. Kitchen is usually launched at about 35,000 ft from where it will climb to about 80,000 ft and cruise at 2.5 to 3.0 Mach before entering a shallow dive to its target which may be up to 250nm from the launch platform (some sources suggest up to 400nm). Alternately Kitchen may be launched directly into a shallow dive at a target up to 170nm away. Kitchen employs inertial or autopilot midcourse guidance and a J-band active radar seeker is used for terminal homing in the anti-shipping versions. IOC for the Bear G was estimated as 1984 and while this aircraft has the ability to hit land targets, its primary role lies in interdicting Western shipping lanes for which it is best equipped.
With targeting data furnished by AV-MF Bear D/F, satellite (radar ocean surveillance satellite systems) and its own radar and ESM systems, Bear G can easily prey on any shipping which isn't covered by an extensive air defence system. The range and speed of the Kitchen coupled with the Bear G's ability to support it with powerful standoff jammers enable the aircraft to attack from beyond a vessel's SAM umbrella. While a USN CBG with its E-2C/F-14/F-18 cover may keep the Bear at bay, other shipping is extremely vulnerable to this 4,500nm radius aircraft.
The Bear H is the newest strike aircraft in this family and is reported to still be in series production at the Kuybyshev plant. This aircraft is Russia's first cruise missile carrier armed with the new AS-15 Air Launched Cruise Missile, conceptually similar to the AGM-109 Tomahawk family.
Based upon the late model Bear F airframe, Bear H carries a J-band Short Horn attack radar and is devoid of most of the blisters and protrusions carried by earlier versions. The ventral barbette is absent together with its associated observation blisters but the tail guns and fire control radar remain. As with the Bear G a small radome is fitted beneath the refuelling probe.
Bear H also has the large fuselage bomb bay of very early versions although it appears that much of the aft fuselage was redesigned, as evidenced by different jointing. The AS-15 ALCM is carried in the bomb bay (8), under the wing roots (4) and offers 1,500nm class range. It is unclear whether this missile employs some form of Tercom guidance, as its deployment coincides with that of the Glonass (Soviet equivalent to US Navstar GPS) satellite navigation system which would be a far cheaper alternative.
Its accuracy is adequate for nuclear strikes. The Russians have certainly made a commitment to Bear H as over 40 of this type are reported in service with the DA VVS and simulated strikes against the Pacific coast of the US have been flown on numerous occasions over the last year. It is expected that Bear H will be supplemented and supplanted by the B-1-like Blackjack A.
The Bear J is the latest derivative of the Bear (and was first reported in this year's edition of Soviet Military Power). This aircraft serves as a Very Low Frequency (VLF) communications relay platform much like the US Navy Tacamo, supporting nuclear ballistic missile launching submarines. While no details were available at the time of writing, the requirement for endurance and airframe life implies the use of new Tu-142M airframes.
Because Bear J must carry a lengthy trailing VLF wire antenna, it will almost certainly use the tailcone fairing common to some C, D and all G aircraft, but in this instance housing the antenna cable drum and supporting drive and feed hardware. No secondary role has been attributed to this aircraft but it may function as an Elint platform.
Despite its age the Bear remains one of the key types in the Soviet inventory, with the DA having roughly 150 aircraft (mainly G/H) and the AV-MF about 100 aircraft (mainly D/F). By Western standards the Bear is a dated and unsophisticated airframe with a large infra-red and acoustic signature and a large radar cross section. It is however adequate for many of its roles and its 4,500nm class unrefuelled operating radius is an asset in its maritime reconnaissance and strike roles.
Hunter-killer pairs of AV-MF Bear D/F aircraft and DA Bear G aircraft represent a capable sea control weapon system which when operated from forward bases such as Cam Ranh Bay can cover a large proportion of the Free World's shipping lanes at extended ranges.
It is surprising that the permanent stationing of eight Bear D/G aircraft at Cam Ranh attracted so little attention in Australia, as this will result in an infrastructure capable of supporting deployments of Bear G strike aircraft at very short notice if required. The haste with which the Government has proceeded with the Jindalee OTH-B radar system is not unreasonable under these circumstances.
As a final thought, it is quite paradoxical that the Bear, a symbol of Soviet global power projection over the last three decades, is a direct descendent of Boeing's B-29. It is worth remembering.
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