Russian Recce

[PR19_Kit]

The Ilyushin Il-28 RV

Even prior to the events of May 1st 1960, when Gary Powers U-2 was shot down by Soviet SA-2 missiles, the Eastern Bloc countries had only been too aware that various aircraft had been overflying their territories on reconnaissance missions, notably the CIA's U-2s and the RAF's Meteor PR19s. Prior to this the RAF had flown a number of PR Canberras over targets of interest in the USSR, and these had even been visually confirmed by PVO Strany pilots, but who were unable to fly at the very high altitudes reached by the Canberras. In addition RB-45 Tornadoes, flown by both USAF and RAF crews, had also made overflights across various Eastern Bloc countries, albeit at lower altitudes than those reached by the Canberras.

Communist China was also aware of similar incursions over its airspace, in this case by Taiwanese operated Canberra RB-57Ds. One of these had been shot down by Chinese SAMs, claimed to be the first ever 'kill' by a SAM incidentally, and much of the airframe had been recovered and displayed in Tiananmen Square. The aircraft, coded '5643', was shot down some six months before the Powers incident, on October 7th 1959, and confirmed only too well what the Western aligned nations were up to.

The eventual fate of 5643 has been open to some conjecture, such Communist Chinese 'successes' usually being displayed in museums for many years, but in this case the RB-57D effectively vanished. Recent research has revealed that the wreck of the long winged Canberra found its way to the Soviet Union in a technology transfer deal with the Chinese and kicked off a very little known aircraft programme there. This was the Ilyushin Il-28RV, the suffix standing for Razvedchik Vysotnyj, meaning high altitude reconnaissance, a suffix also used for the Yak-25RV 'Mandrake' aircraft.

The prototype Il-28RV was a heavily re-built IL-28 'Beagle' light bomber airframe, adapted to follow as closely as possible to the modifications used on the RB-57D. This included the longer wings, with much increased chord, stripped down airframe with all non-essential items removed. In the case of the RV this included two of the crew members as the nose was used for a camera bay and the tail turret was deleted entirely. More radically the RV was fitted with a bicycle undercarriage with outrigger legs retracting into fairings on the side of the engine nacelles.

The latter were much longer than those on the standard Il-28, as indeed was the fuselage, and housed two Tumansky R-11 axial flow afterburning engines. The afterburners were the reason for the new landing gear arrangement as the standard Il-28 mainwheels not only took up too much room in the engine nacelles with the new larger jetpipes, but were not estimated to fare well with the increased temperatures involved.

An increase in fuel tankage was one reason for the new longer fuselage, as the Martin developed honeycomb wing structure of the RB-57D proved to be beyond the technology then available in the USSR. The wing was thus an aerodynamic copy of the American design, but did not include the integral fuel cells used in the big winged Canberra.

Below the fuel tanks the bomb bay area of the IL-28 was modified to contain not only the larger cameras but also the main landing gear. This used twin identical wheel assemblies retracting forward into wheel wells in a similar manner to that employed by Ilyushin on the earlier Il-30 prototype attack aircraft, and which offered gravity deployment in the case of hydraulic failures.

By late 1960, and after the USSR had gained information from of the Powers U-2 airframe, the prototype IL-28RV was ready for taxi trials. While the main Ilyushin Experimental site was close to Moscow itself, the work on the IL-28 took place at their WWII period R&D site at Kuibyshev, in the province of Samara to the southeast of Moscow, thus hopefully keeping it away from any prying eyes. By this time of course the American 'eyes' were not looking as U-2 overflights had been banned by President Eisenhower, but the RAF's 13 Sqdn. Meteor PR19s were still operating over the USSR but with an extremely limited target list which did not include Kuibyshev as luck would have it.
Initial taxi trials of the RV proved to be somewhat problematical as the differential braking effect of the small outrigger wheels had very little effect, and at slow speeds the rudder was ineffective. Twice the aircraft ended up off the taxiway and had to be towed out, so some remedial measures were called for. Re-engineering of the forward main gear included a hydraulic steering ram that solved the problem and enabled further taxi trials, both at low and high speed, to be carried out, with the result that the aircraft was ready for its first flight by early February 1961.

On the morning of February 10th 1961, Viktor Sokolev, the Ilyushin Bureau Kuibyshev Plant's Chief test pilot, taxied the RV to the runway and after a lengthy roll-out lifted off gently into the  low clouds. Climb rate was reported as satisfactory and control response in yaw and roll was precise and smooth, but pitch control required large stick inputs for any effective control. After a climb to some 15000 ft for initial engine tests, without the use of the afterburners, Sokolev decided to return to base due to the lack of effective elevator control. The landing was successful but difficult and the aircraft was returned to the hangar for modifications.

Proposals included a replacement of the entire tailplane with an all-moving version, but eventually settled on one of increased span, thus enabling standard production components to be used for later airframes. Only three weeks later the RV took-off again and this time Sokolev announced he was satisfied with the response and climbed the aircraft to 45000 ft before returning. Throughout the Spring and Summer of '61 flight trials continued and in general terms proved satisfactory. The afterburning Tumanskys provided ample thrust at low and medium altitudes, albeit at the expense of a heavy fuel burn, and only above 48000 ft did they show a lack of power.

As the VVS had specified an altitude requirement of 56000 ft plus this posed a problem for the Ilyushin Bureau, and a special team was setup to solve it. In the meanwhile a small production line of Il-28RVs was laid down and an initial batch of five aircraft were built. During this time the early US reconnaissance satellites had overflown the Samara airfield and photos of the RV had been taken. Initially it was thought that this was the missing '5643' but close examination revealed it to be a new aircraft type, especially as more than one were seen on some passes. The aircraft was given the NATO reporting name of 'Mainbrace', after being initially titled 'Ku-B', but  was not circulated widely as the RVs did not seem to be deployed in service with the VVS.

The five production RVs carried out an intensive test programme for some months and apart from the lack of high altitude power were deemed suitable for service. The aircraft was an excellent camera platform and could carry a wide range of VVS camera fits, together with large film magazines to enable long missions to take place. However the test missions flown were limited to 'friendly territory' and were mainly used to map the COMECON countries with much higher accuracy than had been possible before.

During the Autumn of '61 the special design team came up with their proposed solution, which comprised a twin barrel rocket motor housed in the extended tall cone, with the rocket fuel oxidiser tanks located immediately forward and below the fin. The rocket used kerosene and hydrogen peroxide, thus enabling it to use the RV's main fuel tanks for some of its demands. The rocket was a two chamber engine, developed from the vernier engines used on the R-7 ICBM design of the period. The main engine gave 22000 lbs thrust at full throttle and the smaller sustainer, mounted above it in the tail cone, produced 12000 lbs, which was calculated to maintain the RV at the required 56000 ft after being boosted to that altitude by the turbojets and the main rocket engine.

Within two months the prototype RV had been modified to take the rocket and its controls and Sokolev embarked on a further series of flight tests. Initially only using the rockets at altitude, but later in all flight regimes apart from the landing phase, the performance of the RV was improved out of all recognition. The required altitude was easily reached and maintained for some 15 mins, as specified and the rockets proved to be remarkably trouble free. The only major problem turned out to be handling the hydrogen peroxide on the ground, copious quantities of water being needed to dilute and wash down any spills.

Two of the production RVs were also modified to take the booster rockets and these were trialled by the VVS recce units satisfactorily. However the short history of the Il-28RV was about to come to an end. On April 26th 1962 a stop work order was received at the Ilyushin Bureau and all six of the RVs were grounded.

All the time the IL-28RV had been developed, the 'other RV', the Yak-25RV, NATO name 'Mandrake', had been in a similar situation, taking many of its characteristics from the U-2, and being a much smaller aircraft was considerably simpler and cheaper. In addition it used non-afterburning engines and did not need rockets to reach its operational altitude. There is also some belief that political pressure applied by Yakovlev himself may have been a factor in the decision, there being no love lost between Yakovlev and Ilyushin.

It's ironic to note that on that same day the Lockheed A-12 Mach 3 reconnaissance aircraft made its first flight from Groom Lake in Nevada. The short life of the Il-28RV was surely at an end.


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Watch out for this in plastic in a Forum near you........

[Martin H]

This should be good

[PR19_Kit]

This should be good

That shows you've yet to build an Airfix Il-28, let alone two of them. 

Coming from the period when the number of parts was king, just one of the engine pods has around 12 parts!! Strewth........

[Martin H]

And i doubt ill ever build one Kit, (the airfix kit that is) The only Il-28's in my stash are a pair of Bilek/Italeri/Zvesda offerings

[PR19_Kit]

Martin,

I'm starting to think I should have started with the Bilek version too. Finding bits that actually fit is proving difficult.........