the J58 engines buried in the rear fuselage, and twin vertical surfaces at the rear. The intakes and exhausts were arranged to reduce radar cross section, and the entire aircraft had the same sort of angular appearance as the later Lockheed F-117. The leading edges of the wings and intakes continued to use pyroceram, while other portions used a variety of materials selected for low radar reflection, including fiberglass. The new engines reduced the cruise speed to Mach 3.2, compared to Mach 4.2 for the FISH, but range was increased to about 3,400 nm (6,300 km). In July 1959, Lockheed and Convair presented preliminary designs and RCS estimates to the review panel. Lockheed's was designated the A-12, and was a variation of their A-11 design. President Eisenhower was briefed on 20 July and he approved moving ahead with a final decision. On 20 August, the companies presented their final designs for Kingfish and the A-12. Lockheed's design was estimated to have longer range, higher altitude and lower cost. Johnson expressed skepticism of Convair's claimed RCS, and complained that they had given up performance to achieve it: "Convair have promised reduced radar cross section on an airplane the size of A-12. They are doing this, in my view, with total disregard for aerodynamics, inlet and afterburner performance." On 28 August 1959, Johnson was notified that the A-12 had been selected. The decision was based not only on aircraft performance but also on contractor performance. During the U-2 project, Lockheed had proven its ability to design advanced aircraft in secret, on-time, and under-budget. In contrast, Convair had massive cost overruns with the B-58 and no secure R&D facility similar to the Skunk Works. Lockheed promised to lower the RCS in a modified version of the A-11 known as the A-12, and that sealed the deal. The A-12 entered service with the CIA in the 1960s, and was slightly modified to become the Air Force's SR-71. Aftermath Some small-scale work on the Kingfish continued even after the choice of the A-12, in case the A-12 ran into problems. This did not occur, and the Kingfish funds soon dried up. The CIA continued studies into even higher performance aircraft, and studied replacing the A-12 under Project Isinglass. Isinglass focused on a new design blending features of the General Dynamics F-111 and Kingfish. The new design aimed to produce a reconnaissance aircraft capable of reaching