SR.53 – the great rocket-powered hope!

It was the dying days of WW2, and the German state, and its conquered territories, were being assaulted day and night by the Allies non-stop air offensive. Vital factories producing tanks and aircraft were being hit, transportation nodes were being targeted, and the RAF and USAAF were flattening the synthetic oil plants as fast as they could be identified. This last target policy was the one that was working best, as flying ground slowly to a halt, with the last stocks of aviation spirit having been issued to the Luftwaffe. Desperate times call for desperate measures, and the Luftwaffe now possessed a rocket powered ‘point interceptor’ – the Me163 – which defended important areas, then glided back to the home field, landed on a skid and was removed from the landing area by a special towing vehicle. Now in the last weeks, it intended to use a local defence, semi-disposable (it was intended to recover the Walter motor), rocket-powered interceptor to combat the streams of B-17s and B-24s passing overhead – and the Bachem Ba349 was to be launched from a vertical tower!

As we know, the Me163 made little impact, and the Bachem Ba349 ‘Natter’ was never launched in anger, but in the early 1950s the Royal Air Force was facing a potential tactical problem of similar magnitude. The Tupolev Tu-4, NATO reporting name ‘Bull’ (a reverse-engineered B-29 Superfortress) was equipped with free-fall nuclear weapons, and the Tu-16, NATO reporting name ‘Badger’ (first generation strategic jet bomber) was going to be equipped with short-range stand-off nuclear missiles. It was essential, therefore, that the U.K. and its vital air bases be defended. A fast-climbing interceptor became a necessity.

The Air Ministry issued the Operational Requirement No. 301 in May 1951. This was to be for a rocket-powered interceptor, able to reach 60,000 ft in 2.5 minutes. It was to be ramp-launched, glide in for a landing on an skid undercarriage and then be removed from the landing field using a special towing vehicle. In effect, the RAF had reinvented the Me163 and crossed it with aspects of the Ba329 !

Finally, some sense prevailed, and a new Operational Requirement to G.124T allowed for a mixed-power interceptor, with a rocket motor for initial climb and intercept and a small turbojet for recovery to base. Two companies were awarded contracts for prototypes under Specification F.173D, A.V. Roe (the builders of the Lancaster and Vulcan) and Saunders-Roe who had produced mostly marine aircraft. The Avro 720 ran into technical problems early on, as their chosen rocket engine, the Armstrong Siddeley Screamer (rated at 8,000 lb static thrust) was rather difficult and dangerous technically, as it used liquid oxygen to oxidize the kerosene fuel; the Avro 720 was cancelled on September, 1953.

The Saunders-Roe submission, the SR.53, was a neat clipped delta-wing machine, powered by a combination of the de Havilland Spectre rocket engine (hydrogen peroxide and kerosene) and an Armstrong-Siddeley Viper 8 turbojet of 1,750 lbs static thrust. The idea was for three prototypes to be built, with a first flight in July 1954 and an ‘in service’ date of 1957. However, only two prototypes were finally to be built, XD145 and XD151.

Since the armament required was just two ‘Firestreak’ infra-red guided missiles, and the endurance was only 7 minutes at full power, it was recognized that a bigger aircraft would be of even more utility, so Saunders-Roe simultaneously developed plans for the SR.177. This was to be offered to the Royal Air Force, the Royal Navy and the German Navy, who were expressing a great deal of interest. After all, who better to understand rocket powered flight than the Germans, plus they had a huge potential problem with Soviet air bases being literally minutes away over the East German border!

With such an unorthodox fighter there were bound to be long delays, and it wasn’t until June 1956 that the first tiny SR.53 was rolled out under great secrecy, then transported by road to the RAF’s experimental establishment at Boscombe Down, Wiltshire. On the 16th January, 1957 the very first engine runs were undertaken, and everyone was looking forward to the start of a successful test program. Then it happened – utter disaster!

No, not a structural failure, or an engine problem, no – the infamous 1957 Defence White Paper happened! Presented by Duncan Sandys, one of the most hated men in British aviation history, and the Minister of Defence at the time. It said that ALL defence and attack was to be by rockets in future, and there would be NO MORE manned aircraft developed. Therefore on 4th April, 1957, before even the first flight had taken place, the SR.53 was cancelled. Along with many other fine projects which went under that day, this spelt the virtual end of the independent British aircraft industry. It also spelt the end for the SR.177, also, despite the fact that Saunders-Roe and others fought hard; the contract for the West German Navy went to the Lockheed F-104 Starfighter, in very controversial circumstances (bribery charges involving politicians and a member of the Dutch Royal family were proved).

A limited amount of flying was undertaken under a research contract, which lead to the death ‘under mysterious circumstances’ (the wording on an online RAF Museum document) of the head of the testing program, Squadron Leader John Booth, DFC on 5th June 1958, when he skidded on take-off and slammed into a set of concrete posts. Lieutenant Commander Peter ‘Sheepy’ Lamb, Saunders-Roe’s Chief Test Pilot continued the program, and managed to achieve Mach 1.45 at 56,000ft, with the SR.53 being described as docile and have excellent handling characteristics.

On the 29th December 1958, the surviving prototype was allocated to its manufacturer for aerodynamic research under Contract Kc/2P/04/CB.7(b) …. (don’t you just love Civil Servants?!). Suddenly, on the 29th July, 1960, the Air Ministry instructed Saunders-Roe to stop all further work, immediately. Personally, I think someone at the Ministry had realized that the SR.53 was an embarrassment to them, as Saunders-Roe were still hoping to revive the SR.177 on the back of the research being done with the last SR.53. Therefore on 5th August, 1960, the aircraft was released, and the contract abandoned.

After languishing at the Ministry of Technology, Rocket Propulsion Establishment at Aylesbury, Buckinghamshire (mostly for ground running tests with various experimental rockets), it was consigned to the RAF Museum in May, 1969, and put in store at RAF Henlow. What then happened was usual for an aircraft in store, bits and pieces were removed for various reasons, so when it came time for it to be refurbished for the RAF Museum, it took a three year program of replacing parts and locating a used engine, before it could be rolled out in 1981.

Since March, 1982 the only surviving RAF mixed power interceptor has been where you see it, in the ‘Research and Development’ section of the RAF Museum, Cosford (apart from a little outing to the Royal International Air Tattoo at Fairford on 19/20 July, 2003, to celebrate ‘100 Years of Flight’)

I often wonder, what if? What if the SR.177 had gone ahead (it was to be powered by a Gyron Junior turbojet of about 10,000 lbs st, and a better rocket motor, and be radar and missile equipped). Heinkel, the famous German company who were to build it, had an excellent reputation, and I think it would have proved a formidable interceptor, with a maximum speed of Mach 2.35 and a zoom climb to 100,000 ft – aided by the rocket, of course! Ah, well…..another pipe dream.

2 comments on “SR.53 – the great rocket-powered hope!”

  1. Nice ‘capture’ here, smart looking bird


  2. A thorough, lively and informative report on this aircraft and its era 🙂


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