Original source : http://woondu.com (& http://en.wikipedia.org)
Author : the admin
After the U-2 entered service in 1955 the CIA already planed its eventual replacement. The result was the Lockheed A-12 Blackbird and later the larger Lockheed SR-71. But Lockheed company were not the only company the CIA approached to developed the U-2 replacement. The second company Convair came up with an unusual and innovative proposal known as the Convair Fish and Kingfish, but it never entered operational service.
After cancellation of the B-58B in mid-1959, Convair turned to a completely new design, similar to their earlier entry in name only. The new "Kingfish" design had much in common with the Convair F-106 Delta Dart, using a classic delta wing layout like most of Convair's products. It differed in having two of 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 the "Fish"'s Mach 4.2, but range was increased to about 3,400 nm (6,300 km).