to be no need for Plan Ahead. However, air planners soon pointed out a critical problem. If the Soviets equipped an aircraft with a powerful carcinotron, they could fly it well off the shore and jam the relatively limited frequency band of the BMEWS. This would obscure a missile attack, and the V bombers would be forced to launch until the nature of the threat was determined. If the Soviets repeated this trick, the bomber force and its crews would be quickly worn out. The solution to this problem was to build a much smaller defensive network with enough performance to attack a jammer aircraft while it was still far enough away that the BMEWS would still be operational. This led to a new Ahead layout in 1958 with three stations arranged in a triangle covering the V bomber bases and extending to cover the BMEWS. Even this limited deployment was heavily criticised within the government, not the least of which by Prime Minister Harold Macmillan himself. He desired to move the UK's own force to missiles as well, at which point the network would be superfluous. Eventually, the plan was approved only if all other air defence radars were cancelled, and accordingly, work on the Blue Joker system ended in 1960. Air traffic control Through the 1950s, the RAF had become accustomed to treating the airspace above as their own to use as they saw fit. At that time, the RAF's fighters and bombers were jet powered and flew at altitudes and speeds that the civilian aircraft, mostly propeller-driven, could not touch. The introduction of the first jetliners, and their rapid expansion in the late 1950s, had led to a number of close calls between civilian and military traffic. This would only get worse over time. Some sort of system would be needed to cover the high-altitude traffic across the entire UK, and this led to the National Air Traffic Control Service (NATS) under Laurence Sinclair, who were planning an extensive network of their own based on the new Decca DASR-1 and Marconi S264 radars. Macmillan remained sceptical of Plan Ahead and asked the Chief Scientific Advisor to the Ministry of Aviation, Solly Zuckerman, to consider it. Zuckerman stated there was no way to significantly reduce the estimated cost of the system and still have a military use. However, he suggested one solution would be to use it as