with PCB. According to aviation author Derek Wood, the P.1150 was to have been capable of Mach 1.3. NATO requirements In August 1961, NATO released an updated revision of its VTOL strike fighter requirement, NATO Basic Military Requirement 3 (NBMR-3). Specifications called for a supersonic V/STOL strike fighter with a combat radius of . Cruise speed was to be Mach 0.92, with a dash speed of Mach 1.5. The aircraft, with a payload, had to be able to clear a obstacle following a takeoff roll. Victory in this competition was viewed being of a high importance at the time as it was seem as being potentially "the first real NATO combat aircraft". However, due to changes made to the requirement, the P.1150 was considered undersized and thus unsatisfactory, which led to a desire for a redesign. Wood views the decision not to persist with the original P.1150 design a "serious setback...it would have provided a first class basic type". HSA formed an agreement with the German Focke-Wulf aircraft company to collaborate on a joint study that looked into the issue of equipping the P.1150 with two additional lift engines. However, in October 1961, West Germany elected to entirely withdraw from the programme. This was a blow directly felt not only by HSA and the development team, but by the British Air Ministry, who had been also seeking to collaborate with its West German counterparts on the VTOL aircraft. Meanwhile, further studies served to confirm fears the P.1150 would be too small to meet customer specifications, so Camm initiated work on an enlarged derivative design. In conjunction with HSA's redesign, Bristol worked to enlarge the original PCB engine and raise the exhaust heat to increase thrust to 146.8 kN (30,000 lbf). It could have theoretically reach speeds of up to Mach 1.7–2. The new, larger aircraft design soon emerged, initially designated P.1150/3, then redesignated P.1154. In January 1962, HSA submitted the P.1154 design to NATO via the Ministry of Aviation. NBMR.3 also attracted ten other contenders, among which was P.1154's principal competitor, the Dassault Mirage IIIV. The Mirage IIIV was supported by British Aircraft Corporation (BAC), and also had the favour of several members of the Air Staff. In May 1962, the P.1154 emerged as the winner in the competition for the NBMR.3. While the P.1154 was judged to be technically superior, the Mirage acquired a greater level of political palatability