Elliot's Dual-Band X/Q-band attack aircraft radar (Buccaneer 3)

[JFC Fuller]

I went hunting for the Buccaneer 3 having only previously seen references to it in Roy Boot's "From Spitfire to Eurofighter" and in Cabinet Defence Committee notes. The thing which really stuck out in Roy Boot's description of the proposal Blackburn/HS made was reference to a "High Definition dual-band radar with search, ground mapping and attack modes". This was interesting because Ferranti/Elliot offered a dual-band Q/X-band radar for Tornado in the early 1970s (it lost to a solution from Texas instruments), see here:

http://www.raf.mod.uk/rafcms/mediafiles/F0BEA060_5056_A318_A8C37150DFA8B0F2.pdf

Based on what I found in the archives today, 9-10 years earlier, Elliot Automation offered an almost identical radar solution for the Buccaneer 3, it would also have used a Cassegrain antenna. The key difference seems to be the computer for which Elliots were offering the Autonetics Felecia (Elliots had a close relationship with Autonetics, they were license producing the VERDAN for TSR-2), Elliots were also offering the Autonetics N.16 inertial platform as part of their solution.

Away from the radar specifics: Buccaneer 3 was to A.W.162T, and I have to say it seems to have been a mess. The work done under this requirement seems to lack the analytical rigour that normally accompanies defence programmes in this period. Instead there seems to have been a vague three page requirement drafted that was sent to a range of companies whom subsequently both sent responses independently (like the Elliots one I mention above) and talked to each other. The initially planned in-service date of 1965 was very aggressive and almost certainly unachievable. At some point, the entire effort was redrafted under a new requirement A.W.418 or Buccaneer 2* which itself died late in 1964. A.W.418 looked at a number of possible radar solutions but seemed to favour a variant of the TFR from TSR-2.

There were multiple proposals to both requirements, the file itself is a bit of a state, but I hope to try and identify them all at some point but it would quite the effort. It was the radar I was most interested in, not least because of the striking similarity between it and the proposed Ferranti/Elliot solution for Tornado a decade later.

 

[overscan (PaulMM)]

Interesting, thanks for sharing.

 

[yellowaster]

Interesting. The RRE contracted Elliott to produce an (experimental) Q-band mapping/strike radar with cassegrain scanner sometime circa 1966 for flight trials of various signal processing and display techniques. Apparently in connection with (variously) Buccanneer 2*, AFVG and UKVG. Was flown in a Varsity and then a Canberra in late 1960s/early 1970s. (see "Black Box Canberras" for a photo of the radar in the nose of a Canberra) I've assumed this was the experimental version of the radar being proposed for Tornado. Would be interested in more detail on the Buccaneer 3 dates ie. were Elliott looking at Q-band mapping before the RRE contract ?

 

[JFC Fuller]

If I am reading the document correctly Elliots were offering their Q/X-band solution well before any RRE contract. I will try and check the dates at some point (probably a few weeks though) but I recall it being circa 1962. There is a note in the file from the RRE actually questioning the idea- they seem to have been left out of the loop on A.W.162T initially but ultimately did a very in-depth study (the conclusions of which I have yet to read).

From this Royal Air Force Historical Society Paper, pg.130 "A FOOTNOTE – COULD A DEVELOPED BUCCANEER HAVE FILLED THE BILL?";

...I [Peter Hearne] was guilty of the sin of suggesting to the Director of Naval Air Warfare in 1961 that, since the RAF was getting into the digital age in the TSR2, the RN could get similar benefits by retrofitting their Buccaneers. Although the seed was sown with both the RN and Brough, not much happened at first. However early study work on conventional weapon modes for the TSR2, and early ideas on flexible response, suggested to us at Elliotts, as we then were, that we ought to look at how we could use these new technologies to improve the accuracy of conventional weapon delivery in as wide a range of weather conditions as possible.

With the cancellation of TSR2 this study work speeded up and Elliotts augmented their existing support team at Brough with a very small group of resident senior system engineers. What emerged was a proposal for the now standard type of package for a largish (by mid- 1960s standards) digital computer together with a gas-spin gyro IN platform plus improved displays and an element of auto terrain following.

However, the ‘New Big Thing’ was the proposed radar sensor suite which incorporated a dual X and Q Band Forward Looking Radar together with an LLTV (later FLIR) system. The idea was to try to produce a complementary group of data-fused sensors which started with the longer range detection of the X Band radar, switched to the higher definition of the Q Band in the last part of the run in, with a final ‘low light’ or thermal image for the drop when conditions permitted. It was this same sensor which was put forward jointly by Elliotts and Ferranti for Tornado.

Under Tornado’s collaborative rules, this radar suite would undoubtedly have required a longer and costlier development programme than Texas Instruments’ re-packaged F-111 system. However, at the anticipated start date for the Buccaneer programme in 1967 we were already seeing encouraging Q Band performance in a Canberra test bed and it is arguable that a single-nation development programme would have achieved at least equivalent time scales for a Buccaneer 2* IOC.

Although Brough had dreams of afterburning Mach 1.7 supersonic Buccaneer Mk 31⁄2 versions, it seemed to us, as simple minded system engineers, that this new system package in a minimum-change Mk 2 airframe represented the most cost effective solution. It would have produced a major improvement in all-weather attack capability at an earlier date whilst retaining the Buccaneer’s penetration speed and the advantages of its significantly greater radius of action, points which were brought out in the symposium. It would have retained a big cold- thrust by-pass engine which could have been augmented for take off, either by water injection or, if and when growth was required, by later Spey variants. This seemed a far surer bet than venturing into the world of re-heat, variable intakes and thin wings. All in all it seemed to go some little way towards our basic system specification of being able to detect and identify an enemy soldier on a bike on top of a mountain at night in a rainstorm and then knock him off. As Kosovo and Afghanistan have shown, this is a capability that is still to be developed in 2002.

Such changes as were needed to the Buccaneer airframe were principally in the radome and nose bay volumes, which were enlarged and stretched, the avionic cooling system and the rear equipment bay, and, last but not least, the cockpit layouts where we evicted the ergonomic slum from the rear seat and substituted a creditable glass cockpit with two large side-by-side electronic displays. The extensive nature of the system change was such that it was best built into newbuild aircraft, thus avoiding fatigue life limitations, although it would have been possible to retrofit younger existing Mk 2s if one could have put up with the aircraft down time.

One feature was the improvement of the existing rather simple Sidewinder fit of some RN aircraft with a proper radar-range-bracket- and-seeker-circle acquisition display on a greatly improved HUD, based on the one supplied to the A-7D/E programme. In addition to providing a credible self defence capability, this HUD would have greatly improved flight safety, compared with the primitive ‘stone age’ Strike Sight. The HUD also had its own very capable self- contained weapon aiming and flight director computer facilities, the effectiveness of which were well demonstrated by Skyhawks in action against tanks on the Golan Heights in 1973. As a last ditch attempt to provide an upgrade to the Buccaneer we offered to carry out a contractor-funded installation and trial of the HUD using the existing aircraft sensors, radar, etc on an in-service Mk 2. Although it would have made a major contribution to improving night low level safety factors by replacing the radar altimeter lights with a ‘proper’ height director, as well as providing effective low level CCIP weapon aiming without the need for ‘pop up’, the trial was turned down by OR on the grounds that it might jeopardise the Tornado.

And from pg.60., in relation to the Tornado IDS nav-attack system;

b. The UK Government desperately wanted the Ferranti IN platform, which was a good bit of kit at the time of selection and one into which a great deal of UK Government money had been sunk. They also wanted the Elliott Fly-By-Wire/CSAS/autopilot which was an evolution of the TSR2 Flight Control System.

c. The UK had also proposed a very innovative Ferranti/Elliott- conceived dual band Q/X radar system with a single larger diameter antenna which, it was claimed/hoped, would considerably improve the resolution of the mapping radar for blind attack. They also supported a UK computer selection with some bias towards the Elliott 920 ATC which was a 128k machine (later evolved to 250k) already in hand for the Nimrod Mk 2 sonar with strong in- service software support and provenance from the earlier 920 series computers in the Jaguar and the Nimrod Mk 1.

The experimental flying work for this is referenced in Dave Forster's Black Box Canberras a long with a photo of the antenna and several of a Canberra with the required large nose cone.

 

[JFC Fuller]

The Buccaneer 3 was ostensibly offered up for cancellation, in a Cabinet Defence Committee meeting, in February 1963 and this was re-confirmed in July of the same year in the same forum. It had been stated that the Buccaneer 3 would cost £20-30 million to develop. However, this cancellation came with a very significant caveat;

...but to allow for the normal development of Buccaneer 2.

One of the Royal Navy's roles, as part of NATO strategy, was launching an attack on Northern Russia at the outbreak of War with the Soviet Union (NATO carrier strike group 2). The long range strike role of the Buccaneer was a key component of the UK contribution to this. This is an oft forgotten mission of the UK's Cold War big carrier fleet, in reality a naval liaison officer had been included in the Air Ministry's Targets Committee prior to the creation of the National Strike Coordinating Committee to ensure Air Ministry and Admiralty nuclear strike plans were coordinated, in 1961. The Defence Minister is recorded as feeling that:

...it would be right for the Navy to drop the long-range strike role when the Buccaneer Mark 2 at reached the end of its useful life.

I can not help but think that the emergence of the Buccaneer 2* designation is an almost deliberate attempt to circumvent the abandonment of the Buccaneer 3, which was offered up for sacrifice by the Navy itself. My interpretation is that the Admiralty felt it's carrier programme was under threat, which it was, the Buccaneer 3 discussions take place in that context and it is at the same meetings that the CVA-01 programme is cut from four to three units. So the Buccaneer 3 is offered up as a sacrificial lamb but the Admiralty doesn't really lose anything, it can continue to pursue Buccaneer upgrades and gets to keep the existing aircraft, essentially putting off dropping the long-range strike role indefinitely. Obviously subsequent events undone all this. In the meantime, work on the proposed Buccaneer 3 nav-attack system continued, to eventually be unsuccessfully offered for what became Tornado.

 

[A Tentative Fleet Plan]

More information.

Page 406.

 

[DWG]

More information.

Page 406.

Fascinating to see something substantial and defence related in New Scientist, that's rare as hens teeth nowadays.

 

[Archibald]

One of the Royal Navy's roles, as part of NATO strategy, was launching an attack on Northern Russia at the outbreak of War with the Soviet Union (NATO carrier strike group 2). The long range strike role of the Buccaneer was a key component of the UK contribution to this. This is an oft forgotten mission of the UK's Cold War big carrier fleet, in reality a naval liaison officer had been included in the Air Ministry's Targets Committee prior to the creation of the National Strike Coordinating Committee to ensure Air Ministry and Admiralty nuclear strike plans were coordinated, in 1961.

Fascinating indeed.

 

[A Tentative Fleet Plan]

I've found some images of an Elliott Q-Band Experimental Radar. This could be the Strike Radar, as the Source describes its use as a mapping radar, with its output be overlaid on the Ferranti Moving Map Display.

QER (Q-band Experimental Radar)

At around this time there was increasing interest in exploring the use of shorter wavelengths for radar, and whether good quality mapping could be achieved. We received a research project to produce a ground-based radar for RRE which could be used to compare the quality of mapping of the Malvern Hills (from RRE) using radar at Q-band compared to what the OS maps showed. This required the development of a monopulse aerial system with associated transmitter, receiver etc. Some time into the project the requirements were changed, and we were asked to make the system fully airborne for trials in a Varsity aircraft. I was project leader, and gained invaluable experience during this period. Prior to the airborne trials we carried out trials from the upper floor of our building in Borehamwood, comparing our results against the OS maps. In one trial it looked as though there was an echo in the received signal, as the maps showed just one line of electricity pylons. We checked the circuitry carefully and could find no problems, so visited the area where the echo signals seemed to come from. Since the maps had been printed, another row of pylons had been built, and the finer resolution of our Q-Band aerial combined with a short pulse magnetron had resolved the two rows.

The transmitter and receiver (TR) unit for this radar was housed in a pressurised cylindrical container (pressurised so that the high voltages associated with pulsing the magnetron didn't cause damage by arcing at low pressures), and heat was removed by a forced air circulation system driving air through a heat exchanger in the double wall of the case. Additional cooling was via piped cooling to individual units in the TR unit. Novel zero displacement sealed fluid connectors were designed, and allowed the internal units to be removed for servicing without the need to release other units.

After bedding down trials, test flights were flown with the mapping output fed into a Ferranti moving map display, which I was privilged to see. This allowed the air-crew to see either the OS map or the radar map, or the radar map overlaid onto the OS map thereby confirming one's position.

Source

Archived Source