all of the activity being carried out with NACA and Avro Canada’s liaison with Hawker Siddeley in the United Kingdom, it is logical to assume that both the United States Air Force (USAF) and the Royal Air Force (RAF) in Britain would have observed what was going on in Canada with great interest. In the case of the United States, General Nathan F. Twining, chief of staff, USAF, had advised the Canadian chief of the air staff, Air Marshal Roy Slemon, that the USAF was interested in a long-rage interceptor and had initiated a design competition among American manufacturers.
It was June 1954, and General Twining was expressing a specific interest in the CF-105, so much so that he had requested the Air Research & Development Command (ARDC) in the United States to evaluate the specifications of the Canadian plane with those in the design competition. On July 15, 1954, Air Marshal Slemon replied and forwarded a copy of A.V. Roe’s design study. He also stated he was pleased to open this exchange of information with the Americans. It was in keeping with the doctrine of requiring “the enemy to compete in the technological field with the combined brains and resources of the English-speaking Allies rather than three components thereof … [because] such collaboration would be superior to the individual and in some cases overlapping efforts.”2 Slemon pointed out that approval to proceed with the CF-105 was based on the knowledge that neither the United States nor the United Kingdom had or were planning to develop a similar aircraft.
The exchange of letters resulted in a team of RCAF and Avro officials providing a briefing to the ARDC on August 26, 1954. The briefing was well received, and later in 1955, when USAF assistance was requested in arranging for special wind-tunnel testing at facilities not available in Canada, help was provided without hesitation.
Despite the progress Avro was making and its vindication at NACA headquarters the previous year, Air Marshal Slemon, together with Dr. Omond Solandt, chairman of the DRB, decided an independent evaluation of the project was needed. A high-level technical delegation of USAF personnel was invited to visit Avro and study the program between October 31 and November 1, 1955. The USAF team was headed by Major General G.E. Price, director of requirements and deputy chief of staff (development). It included members from ARDC and the propulsion and fighter branches of USAF headquarters.3
The American team was told by the RCAF that increasing costs had led to a reappraisal of the project, that the defence budget was limited, and that, therefore, continuation could lead to elimination of other desirable programs. The USAF was requested to provide an opinion as to the “essentiality of the 105 Project to the defence of North America” and was asked flat out if it would abandon the program under similar circumstances! The defence of Canada had expanded to include the defence of North America, and it is probable that the Canadians were hoping to interest the USAF in eventual acquisitions. Still, it is inconceivable that the question of continuing or abandoning the project would be put so bluntly, especially when one factors in the “Buy American” mentality that might shape any answer from the USAF. Also, one might ask how well the defence of Canada had been studied by the experts before embarking on the Arrow, and if Canadian confidence was so low that the RCAF had to keep running to the United States for answers and advice. Would this become a factor in the cancellation later on?4
The USAF team was also told that the development of a new engine, the PS-13, or Iroquois, was linked to the airframe development, and that cancellation of the airframe would remove justification to proceed with the PS-13. Finally, USAF views were sought regarding choice of missiles, fire control, development costs with respect to similar U.S. projects, and comparisons to other U.S. aircraft under development. To help in its deliberations, the USAF team was handed the latest facts and figures on the project, with the parting comment that Canadian requirements in terms of numbers of aircraft would be small and therefore unit costs would be high. Even at such an early stage, it seems every vulnerability was being exposed and the very future of the project was being placed squarely in the hands of the United States.5
During the ensuing discussions, the differences in the performance between Avro’s calculations and those of the NAE and the DRB were again tabled and discussed. The U.S. team also inspected the mock-ups and tooling bays in the plant and was told of the versatility that could be incorporated into the aircraft. A full briefing was provided on the Iroquois engine being developed by Orenda.
On technical soundness, the delegation thought the risks were reasonable for such an advanced design: “In their opinion to attempt to achieve Mach 1.5 and a 2-g turn at 50,000 feet was quite a technical advance, but they saw no reason why the design should get into any particular trouble…. The delegation did not seem unduly perturbed by the fact that there was a difference of opinion about what the performance might actually be.”6
The USAF requirement for manoeuvrability was only 1.2 g at combat ceiling. Most aircraft will pull far more than 2 g, but to do it at altitude without losing power or height is quite remarkable even by today’s standards. (G measures the force of gravity on an accelerating body. To appreciate g force, think of the feeling of being pulled sideways when you make a sharp turn in a car. Or think of a roller coaster; as you go screaming down to the trough, g builds up, so that when you abruptly curve and go upward again, you feel g force pinning you to the back of your seat.)
A list of U.S. aircraft under development or consideration was tabled. It included the short-range F-102B, the medium-range F-103 to be available by 1962 or 1963, the long-range F-101B, and the long-range LR-1x1 and LR-1x2. The conclusion drawn by the Americans was that the CF-105 would be the only aircraft available to supplement the limited altitude capabilities of the F-101B prior to service of the LR-1x1 interceptor.
In fact, the U.S. team admitted that if the LR-1x1 was given the go-ahead, it would probably not be ready for service until some five to six years after the Arrow, well into the 1960s. It was also noted that for the LR-1x1 to obtain the hoped for 100-mile acquisition range for targets, a technical breakthrough in radar development would be required, and this could further delay its in-service timing. There were also stated problems with the navigation, communication, and fire-control subsystems of the aircraft.7 The long-range project would eventually be cancelled, and some people would use this as justification for the Arrow cancellation, stating that the manned interceptor was considered obsolete. But given all the problems cited by the Americans, was the LR-1x1 not cancelled for technical reasons?
With respect to the F-102B, the Canadians asked if it could operate outside the Semiautomated Ground Environment (SAGE). SAGE was a ground-based surveillance and weapons control system that could transmit data to the aircraft and automatically guide it to the target. The answer was that the F-102 was not the best aircraft to operate outside the SAGE. Hence, the utility of the F-102 for target interception would be limited to the range of the SAGE system, even though the aircraft might physically fly beyond the SAGE perimeter. This range problem would later prove to be one of the limitations of the Bomarc missile, as well. The Arrow, however, was designed to operate well beyond SAGE and did not require the assistance of SAGE during the target-interception process. In his memoirs, Prime Minister John Diefenbaker would intimate that it was the Arrow that could not operate outside of this sophisticated ground environment.
The medium-range F-103 was also discussed, but the USAF pointed out that no funds had yet been committed to this project and that technical advances in electronics would likely be needed to achieve its required performance. The Arrow appeared to remain the best aircraft that would be available in the time required, reinforcing the opinion that no American aircraft were suitable to meet the RCAF requirements.8
Considerable opinion was expressed concerning the PS-13, which Orenda was designing as a titanium engine. U.S. engine manufacturers had experienced numerous problems with titanium; however, as pointed out by the Americans, their companies were trying to integrate titanium parts into existing engines, while Orenda was designing with titanium from the start. Therefore, they expected that Orenda would not encounter the same difficulties. Given the expected high performance of the engine, the American team also wondered
