The Saunders-Roe SR.177 was a 1950s project to develop a combined jet- and

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

-powered

interceptor aircraft An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are c ...

for the

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

(RAF) and

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

. It was an enlarged derivative of the

Saunders-Roe SR.53 The Saunders-Roe SR.53 was a British prototype interceptor aircraft of mixed jet and rocket propulsion developed for the Royal Air Force (RAF) by Saunders-Roe in the early 1950s. As envisaged, the SR.53 would have been used as an interceptor ...

, which was itself an experimental combined jet-and-rocket interceptor aircraft. The SR.177 principally differed from the smaller SR.53 in its adoption of a nose-mounted

aircraft interception radar Aircraft interception radar, or AI radar for short, is a historical British term for radar systems used to equip aircraft with the means to find and track other flying aircraft. These radars are used primarily by Royal Air Force (RAF) and Fleet A ...

unit, which allowed it to scan for and lock onto its own targets; a more powerful turbojet engine was also incorporated. In addition to British interests in the aircraft, the

German Navy The German Navy (, ) is part of the unified (Federal Defense), the German Armed Forces. The German Navy was originally known as the ''Bundesmarine'' (Federal Navy) from 1956 to 1995, when ''Deutsche Marine'' (German Navy) became the official ...

had also expressed their interest in the project and closely evaluated its progress with an eye towards its potential procurement. However, the SR.177 was ultimately cancelled as a result of changes in Britain's military policies in 1957. A much larger derivative of the SR.177 had been studied, which was designated as the SR.187, and was being developed with the intention of meeting the requirements of

Operational Requirement F.155 Operational Requirement F.155 was a specification issued by the British Ministry of Supply on 15 January 1955 for an interceptor aircraft to defend the United Kingdom from Soviet Union, Soviet high-flying nuclear-armed supersonic bombers. Discus ...

. However, this work was also cancelled in 1957. By the time of termination, approximately 90 per cent of the first prototype had been completed, while several other prototypes were in various states of completion.London 2010, p. 34. The prototypes were stored for several years while attempts were made to revive the project; while interest was present, including from

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, nothing more came of the project and the remaining assets were broken up.

Design and development

Background

In 1952, Saunders-Roe had been awarded a contract to develop a combined

-and- jet-propelled

, which was designated as the

.Wood 1975, p. 57. However, as development work on the project progressed, the shortcomings of the design became increasingly evident. Most particularly, as with the

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

rocket-powered interceptors of the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, the range and endurance of such an aircraft were limited by the high rate of fuel consumption by the rocket engine. However, as turbojet engines developed and became increasingly powerful and efficient, new powerplants were quickly becoming available that would make such aircraft more practical. Maurice Brennan, the chief designer of the SR.53, had also become convinced of the necessity for an airborne radar unit to be carried by the aircraft, as the SR.53 was reliant upon on ground-based radar guidance and the pilot's own vision to intercept aircraft. In particular, it was feared that pilots would be unable to focus their eyes properly at the altitude that the SR.53 was capable of. Out of a combined desire to equip the aircraft with a radar unit and to make greater use of turbojet power, a more ambitious design began to be drawn up.Wood 1975, pp. 57-58. While it had begun as an advanced design concept for the SR.53, upon the issuing of a development contract by the

Ministry of Defence A ministry of defence or defense (see American and British English spelling differences#-ce.2C -se, spelling differences), also known as a department of defence or defense, is the part of a government responsible for matters of defence and Mi ...

in May 1955 (to meet specification F.155), the project was given its own designation as the SR.177. As work continued on the SR.53, a separate High Speed Development Section was formed by Saunders-Roe to work on the SR.177.Wood 1975, p. 58. Initially, the SR.177 was a straightforward development of the SR.53, sharing much of the same configuration and equipment, and it was envisioned that the first test flight would take place during the first half of 1957. However, in February 1955, an extensive redesign of the SR.177, with the aim of making the type suitable for use by both the RAF and the Royal Navy, was commenced. Of the changes made to the aircraft, major differences included the repositioning of the jet engine to the lower fuselage lobe, which was now fed with air via a large, chin-mounted intake; the wing was also enlarged and

blown flap Blown flaps, blown wing or jet flaps are powered aerodynamic high-lift devices used on the wings of certain aircraft to improve their low-speed flight characteristics. They use air blown through nozzles to shape the airflow over the rear edge of ...

s were adopted. The turbojet engine selected was the

de Havilland Gyron Junior The de Havilland Gyron Junior is a military turbojet engine design of the 1950s developed by the de Havilland Engine Company and later produced by Bristol Siddeley. The Gyron Junior was a scaled-down derivative of the de Havilland Gyron. Des ...

, capable of generating of thrust.Wood 1975, p. 59.

Project launch

In September 1955, Saunders-Roe received instructions to proceed on the SR.177 from the British

Ministry of Supply The Ministry of Supply (MoS) was a department of the UK government formed on 1 August 1939 by the Ministry of Supply Act 1939 ( 2 & 3 Geo. 6. c. 38) to co-ordinate the supply of equipment to all three British armed forces, headed by the Ministe ...

. The Ministry also gave instruction for the production of mock-ups, windtunnel tests, and the development of construction

jig The jig (, ) is a form of lively folk dance in compound metre, as well as the accompanying dance tune. It first gained popularity in 16th-century England, Ireland, Scotland, and other parts of the British Isles, and was adopted on mainland Eu ...

s for the manufacture of an initial batch of aircraft.Wood 1975, pp. 63-64. From the onset, the SR.177 faced competition in the form of an enlarged derivative of the

Avro 720 The Avro 720 was an in-development British single-seat interceptor of the 1950s. It was designed and being developed by Avro in competition with the Saunders-Roe-built SR.53. While at least one prototype was partially-constructed, the order for ...

, which had itself been devised as a competitor against the smaller SR.53. Avro promoted the 720 to the Royal Navy, hoping to win favour away from the SR.177, which had by this point reached the detail design phase.Wood 1975, pp. 59-60. The Ministry ultimately opted to cancel all work on the Avro 720, primarily as a cost-saving measure, as well as to concentrate development work on HTP-based rocket motors, such as those powering the SR.53 and SR.177.Wood 1975, p. 61. The most significant difference between the SR.53 and SR.177 was the latter's use of a jet engine with nearly five times the thrust of the one adopted for the former. While the SR.53 had relied mostly on its rocket engine for climbing, the SR.177 would be able to add considerable endurance by conserving use of its rocket for the dash towards a target only. It was expected that the added endurance would allow the SR.177 to perform roles other than pure interception; these roles were expected to include strike and

reconnaissance In military operations, military reconnaissance () or scouting is the exploration of an area by military forces to obtain information about enemy forces, the terrain, and civil activities in the area of operations. In military jargon, reconnai ...

missions. The SR.53 design had been considerably enlarged to accommodate the new engine, and the original sleek lines were forfeited for the chin-mounted air intake. Following the

maiden flight The maiden flight, also known as first flight, of an aircraft is the first occasion on which it leaves the ground under its own power. The same term is also used for the first launch of rockets. In the early days of aviation it could be dange ...

of the SR.53 in May 1957, the development of the SR.177 became the main focus of activity at Saunders-Roe.Wood 1975, p. 63. At this point, the project was viewed as having considerable large scale potential, as both the RAF and Royal Navy appeared to be set to be customers for the SR.177. The RAF sought to operate it alongside the incoming

English Electric Lightning The English Electric Lightning is a British fighter aircraft that served as an interceptor during the 1960s, the 1970s and into the late 1980s. It is capable of a top speed above Mach 2. The Lightning was designed, developed, and manufactured ...

interceptors while, according to aviation author Derek Wood, the Royal Navy also had considerable interest in the programme. When the development contract had been issued in May 1955, it reflected this dual interest. The Navy's requirements were defined in NA.47 while the RAF's requirements were specified in OR.337, which had been issued by the Ministry of Supply as

. There was optimism that a joint aircraft for the two services could be developed, saving considerable expense, time, and effort.Wood 1975, p. 64. Negotiations on the exact number of aircraft sought by either service were protracted; but it had been established that there was demand for an initial batch of 27 SR.177 aircraft, and that sufficient tooling should be produced to enable the programme to transition rapidly to full-rate production. By April 1956, a consensus had emerged that, in order for the first five SR.177s to be completed by January 1958, these aircraft would be produced without any A.I. radar or the ability to support armaments. In July 1956, funding was secured for 27 aircraft to be produced, the first of which being expected to fly by April (later postponed to October) 1958. On 4 September 1956, a formal contract for the 27 aircraft was issued, which was sub-divided into four batches of five, four, four, and fourteen respectively, although the final eighteen were subject to evaluation and were thus pending confirmation.Wood 1975, p. 64. During 1957, a development contract for the SR.177 was announced for its use with the Royal Navy."From All Quarters: SR.177 Development Contract."
''

Flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

'', 18 October 1957, p. 602. By January 1957, the design of the main component jigs was 70 per cent complete while the component assembly jigs were almost 50 per cent complete; the manufacture of a quantity production batch was nearing, which would have likely been subcontracted to another aviation company due to the high level of workload at Saunders-Roe's Cowes facility.Wood 1975, p. 66.

Armstrong Whitworth Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Tyne and Wear, Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomot ...

, who had already taken over work on the basic wing design of the SR.177, had been selected as the second production outlet for the type. The selection of a production center for the SR.177 was complicated by a favourable event; interest in the programme from the

West German West Germany was the common English name for the Federal Republic of Germany (FRG) from its formation on 23 May 1949 until its reunification with East Germany on 3 October 1990. It is sometimes known as the Bonn Republic after its capital c ...

government. Since 1955, the revived German Air Force had sought a suitable high performance aircraft to equip itself with, and there were hopes that the SR.177 could become the foundation of a collaborative European fighter programme. The German Defence Ministry had first expressed interest in the SR.177 in October 1955; in February 1956, the British Government Committee on Security consented to discussions being held on the SR.177.Wood 1975, pp. 66-67. The prospects of a large German order for as many as 200 aircraft, and for the SR.177 to be manufactured under licence in Germany by the recovering German aircraft industry, were soon being aired, of which the British government declared its openness towards.Wood 1975, p. 67. In January 1957, the Anglo-German Standing Committee on Arms Supply reported that General Kammhuber, the Commander-in-Chief of the German Air Force, was concerned that, due to a lack of available financing until April 1958, the delivery timetable may not be satisfactory. According to Wood, Germany was keen to issue an order as soon as possible by this point.Wood 1975, pp. 67-68.

Decline and cancellation

During 1957, the fate of the SR.177 was to be subject to a massive re-thinking of air defence philosophy in Britain, being principally outlined in the

1957 Defence White Paper The 1957 White Paper on Defence (Cmnd. 124) was a British white paper issued in March 1957 setting forth the perceived future of the British military. It had profound effects on all aspects of the defence industry but probably the most affected wa ...

, which called for crewed combat aircraft to be replaced by

missile A missile is an airborne ranged weapon capable of self-propelled flight aided usually by a propellant, jet engine or rocket motor. Historically, 'missile' referred to any projectile that is thrown, shot or propelled towards a target; this ...

s. Very shortly afterwards, OR.337 was cancelled and the prospects of an order from the RAF had evaporated.Wood 1975, pp. 68-69. This was a serious blow, while it the Royal Navy and Germany remained potential customers for the SR.177, the confidence of both parties was shaken by the move.Wood 1975, p. 69. Work on the SR.177 continued for a little longer, however, in the anticipation of continued interest from Germany. In September 1957,

Aubrey Jones Aubrey Jones (20 November 1911 – 10 April 2003) was a British Conservative politician who served as Member of Parliament for Birmingham Hall Green from 1950 to 1965. Early life Jones was born in Penydarren. He attended Cyfarthfa Castle Se ...

, the Minister of Supply, was keen to support the programme and had agreed to continue funding development of five of the six prototypes. However, according to Wood, the SR.177 was subject to political in-fighting between Aubrey Jones and

Duncan Sandys Duncan Edwin Duncan-Sandys, Baron Duncan-Sandys (; 24 January 1908 – 26 November 1987), was a British politician and minister in successive Conservative governments in the 1950s and 1960s. He was a son-in-law of Winston Churchill and played a ...

, the minister who had been the prime advocate of the Defence White Paper. While Jones assured German officials that the SR.177 project was continuing, Sandys contacted them to inform them that the aircraft was effectively dead. These mixed messages led to considerable confusion and apprehension within the German Defence Ministry. Further difficulty was added when, in response to lobbying by

Rolls-Royce Limited Rolls-Royce Limited was a British luxury car and later an aero-engine manufacturing business established in 1904 in Manchester by the partnership of Charles Rolls and Henry Royce. Building on Royce's good reputation established with his Crane ( ...

, the German government insisted that the Rolls-Royce RB.153 engine be used in place of the Gyron Junior, causing Saunders-Roe to work on a further hasty redesign of SR.177. The German government also decided to change its priorities from seeking an interceptor aircraft to acquiring a

strike fighter In current military parlance, a strike fighter is a multirole combat aircraft designed to operate both as an attack aircraft and as an air superiority fighter. As a category, it is distinct from fighter-bombers, and is closely related to the co ...

instead, leading Saunders-Roe to redesign the aircraft for this role. However, even with

Heinkel Heinkel Flugzeugwerke () was a German aircraft manufacturing company founded by and named after Ernst Heinkel. It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight, wit ...

preparing to manufacture the SR.177 locally under licence, Germany chose to withdraw support from the venture in December 1957. The Minister had visited the German government in November 1957 as the Germans wanted the arrangements to be between governments instead of between their government and Saunders-Roe."West German Defence Policy."
''

'', 14 February 1958, p. 195. Of the remaining aircraft under consideration, the West German Government chose to purchase a development of the American

Lockheed F-104 Starfighter The Lockheed F-104 Starfighter is an American single-engine, supersonic interceptor. Created as a day fighter by Lockheed as one of the " Century Series" of fighter aircraft for the United States Air Force (USAF), it was developed into an ...

interceptor instead to meet the role of "high-altitude reconnaissance machine, a tactical fighter-bomber, and an all-weather fighter", along with the majority of European governments. This Lockheed coup, known as the "Deal of the Century", caused major political controversy in Europe and the West German Minister of Defence

Franz Josef Strauss Franz Josef Strauss ( ; 6 September 1915 – 3 October 1988) was a German politician. He was the long-time chairman of the Christian Social Union in Bavaria (CSU) from 1961 until 1988, member of the federal cabinet in different positions between ...

was almost forced to resign over the issue. During later investigation into Lockheed's business practices, it was discovered that Lockheed had paid out millions of dollars in "sales incentives" in each of these countries in order to secure the deal.

Prince Bernhard of the Netherlands Prince Bernhard of Lippe-Biesterfeld (later Prince Bernhard of the Netherlands; 29 June 1911 – 1 December 2004) was Prince of the Netherlands from 6 September 1948 to 30 April 1980 as the husband of Queen Juliana. They had four daughters to ...

confessed to taking more than one million dollars in bribes from Lockheed to buy the F-104.Wood 1986, pp. 67–69. Following the withdrawal of German interest and there being no requirement for the SR.177 by the RAF, the existing Royal Navy requirement was considered not worthwhile to proceed with. Accordingly, the Ministry of Supply soon chose to cancel the project. On 24 December 1957, a letter from the Ministry was received by Saunders-Roe, announcing the decision to terminate.Wood 1975, p. 70. Saunders-Roe announced that it expected to make 1,000 workers

redundant Redundancy or redundant may refer to: Language * Redundancy (linguistics), information that is expressed more than once Engineering and computer science * Data redundancy, database systems which have a field that is repeated in two or more table ...

as a result of the termination. As the jigs and near-complete aircraft was disassembled during the New Year, it was decided that the aircraft assemblies themselves should be stored in the event of the project being revived. In 1958, the SR.177 received one last burst of interest when

, which was interested in developing a rocket-jet fighter itself, approached Britain with a request for quotations for the purchase of the two prototype SR.53s along with the completion of two SR.177s. However, due to a lack of backing from the British government, this initiative did not come to anything; the Japanese ultimately turned to the F-104 as well. Woods summarises the cancellation of the SR.177 as: "...it could ultimately have been built in hundreds or thousands. Due to ridiculous defence policies and a complete lack of Whitehall inter-departmental collaboration in the technology field, one of the most promising projects in a decade was destroyed".

Specifications (SR.177 estimated)

References

Notes

Bibliography

* London, Peter. ''Saunders and Saro Aircraft since 1917.'' London: Putnam & Company Ltd., 1988. . * London, Peter. "Saunders-Roe's Rocket Fighters." ''Aircraft'', Vol. 43, No. 7, July 2010. * Mason, Francis K. ''The British Fighter since 1912.'' London: Putnam, 1992. . * Winchester, Jim. "TSR.2." ''Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft''. Kent, UK: Grange Books plc., 2005. . * * Wood, Derek. ''Project Cancelled: The Disaster of Britain's Abandoned Aircraft Projects''. London:

Jane's Janes is a global open-source intelligence company specialising in military, national security, aerospace and transport topics, whose name derives from British author Fred T. Jane. History Jane's Information Group was founded in 1898 by Fred ...

, 2nd edition, 1986. .

External links

Unreal aircraft

*

{{DEFAULTSORT:Saunders-Roe Sr.177 1950s British fighter aircraft Rocket-powered aircraft Mixed-power aircraft SR.177 Cancelled military aircraft projects of the United Kingdom Mid-wing aircraft Aircraft with retractable tricycle landing gear