Facts and figures
The SR53 was a relatively small aircraft, only weighing 7,400 lb empty, but 18,400 lb fully fuelled. It was an extremely elegant aircraft, its only drawback in looks being a slightly tubbiness in the fuselage as a consequence of the large amount of fuel that needed to be carried. The wing span without missiles was 25 ft 1 inch, and it was 45 ft long.
This project grew from the realisation of the limitations of the SR53. It would have been a larger aircraft, with a much more powerful jet engine: the balance of jet and rocket would be almost equal. In addition to the de Havilland Spectre motor, capable of 8,000 lb thrust, it would also have a de Havilland Gyron Junior turbojet, also of 8,000 lb thrust. In addition, it was given a limited Air Interception capability, which extended the range of weather conditions and night time operations. Coincidentally, the Navy was looking for a high-flying supersonic interceptor at the same time, and both Services, rather unusually, concluded that the same aircraft would suit them both. Proposals were sent to the Ministry of Supply in March 1954 and a design contract was placed with the company in May 1955. With remarkably little fuss, development of the P177 began in autumn 1955, and work proceeded steadily throughout 1956.
A memorandum by the First Lord of the Admiralty in April 1956 set out the Navy’s case for the aircraft5:
The P.177 is a single seat high altitude fighter capable of operating at a sustained speed of M = 1.4 in the 40,000 to 60,000 ft height band; its ceiling will be in the region of 75,000 ft and it will be capable of reaching M = 2 for short periods. It will be armed with 2 Blue Jay Mark 3 air to air Guided Missiles, with unguided rockets as an alternative armament. It will be equipped with AI [AI = airborne interception] and will have a limited capacity for night operations…
The P.177 was selected by the Naval Staff because:-
(i) It is one of the very few British aircraft likely to be better than anything American when it comes into service.
(ii) It is the only aircraft required by both the Navy and the RAF.
(iii) Its engine, radar and weapons are already being developed for other air-craft, so that the development costs should be comparatively low.
(iv) It is smaller and cheaper than the N.113 [Supermarine Scimitar] and its early substitution for that aircraft will save production expenditure.
However, two factors now intervened to threaten the project. One was a change in defence policy with regard to manned aircraft, and the second was a need to reduce the UK’s defence spending. With the arrival of Duncan Sandys at the Ministry of Defence, and the resultant 1957 Defence White paper, the RAF version was cancelled forthwith. As the White Paper put it:
Work will proceed on the development of a ground-to-air missile defence system, which will in due course replace the manned aircraft of Fighter Command. In view of the good progress already made, the Government have come to the conclusion that the R. A.F are unlikely to have a requirement for fighter aircraft types more advanced than the supersonic P1, and work on such projects will stop.
Given the extent to which the RAF was threatened, the P177 was relatively small fry, and the P1 interceptor, or Lightning as it became known in service, gave many years of service in a very similar role.
However, the Navy was still very insistent that they needed the P177, and at the same time, Aubrey Jones, who was Minister of Supply, wanted to keep the project going since there was some German interest in the aircraft. A prolonged Whitehall battle then ensued. Sandys told the Navy quite firmly that the aircraft, irrespective of merit or the Navy’s need, could not be afforded. In the same way he told Jones that if the Ministry of Supply wanted to keep the project under way then it would have to go on his budget, not Sandys’.
All this wrangling cannot have helped the progress at Saunders Roe, or the prospect of trying to sell it to the German Air Force. After all, if the RAF version had been cancelled and then the Naval version, this cannot have inspired confidence in the project. In addition, not everyone wanted to sell it to the Germans. Sir Frederick Brundrett, Chief Scientist at the Ministry of Aviation is on record as saying that the German requirement.
.. .was for a high-altitude quick climbing defensive weapon. There was no doubt that they would be best satisfied with a guided weapon and in his view the right course was to interest them in our own Stage 1 and Stage 1 and a half guided weapon developments rather than the P.177.
The Germans did not share his view, however, and in December 1957 the project was finally cancelled.
Figure 32. The P177 as it might have appeared in naval service.
Would the P177 have lived up to expectations? There is a strong probability it would have done: its smaller sibling, the SR53, did all that was expected of it. The RAF was left with the Lightning, the Navy with nothing. It could be argued that the P177 would have been too specialised for the Navy: it would not have been able to maintain a continuous Combat Air Patrol as its endurance was too limited, although it was intended to fit a probe for air-to-air refuelling. But that was not its function: it was intended to by-pass the patrolling function by its ability to reach high fast targets quickly. The concept was never put to the test, but by the late 1950s it was becoming obvious that jets such as the Lightning with re-heat on the engines could do the job as effectively as rockets.
The Lightning, however, went on to prove its usefulness against the Soviet aircraft that during the 1960s and 1970s attempted to probe British airspace. A manned aircraft does have some advantages over missiles, as the Falklands demonstrated. In reality, both are needed since they are complementary.
The Germans went on to buy Lockheed F-104 Starfighters, as did many other NATO countries. Saunders Roe was a minnow by comparison with Lockheed, and whether as many P177s would have fallen out of the sky as F-104s is also an interesting question. But the most fascinating image is of the P177 in Luftwaffe colours!
The P177 was a good deal less elegant in appearance than the SR53, the rather bulbous fuselage and pointed nose above the air intake detracting from its appearance. It was twice the weight at 14,500 lb empty, and 28,000 lb at extended load. The span was 27 ft, and it was 50 ft 6 inches long. It was within about six months of its first flight6 when the project finally cancelled in December 1957.
A history of the SR53 and P177 projects written by the Air Ministry can be found in Appendix A.