posted on Apr, 2 2007 @ 04:46 PM
Kelly Johnson submitted the A-10 concept in February 1959. It had a 109-foot-long cylindrical fuselage and semi-double-delta wings with squared tips
that spanned 46 feet. A vertical tail fin with conventional rudder provided lateral stability. It was to be powered by two General Electric J93-3
turbojets. RCS was a problem, but Johnson was more concerned with performance.
The following month he developed the A-11, featuring true double-delta wings spanning 56.67 feet. Fuselage length increased to 116.67 feet and the J93
engines were replaced with J58s. The A-11 was designed to cruise at Mach 3.2 at 93,500 feet and complete an eight-hour, 13,340 nautical mile mission
with two aerial refuelings.
Johnson pitched his A-11 concept to the CIA and reported the results of six months of radar studies. He emphasized that expected improvements to radar
systems would enable detection of any conceivable airplane that would fly in the next three to five years. He noted that the probability of detection
of the A-11 was practically 100 percent. It was subsequently agreed the airplane might make such a strong radar target that it could be mistaken for a
On July 3, 1959, Johnson received a visit from the director of the Program Office at CIA headquarters. He thought Lockheed was about to be ruled out
as a contender, but the CIA instead offered to extend Lockheed’s program and accept lower cruising altitudes in exchange for reduced RCS.
Johnson subsequently proposed the A-12 design, with the J58 engines in a mid-wing arrangement to reduce the airplane’s side profile. Chines along
the forebody reduced fuselage sloping while providing additional lift and stability. The single vertical stabilizer was replaced with two all-moving
vertical fins, one on top of each engine nacelle. They were canted inward for further RCS reduction. Serrations on the wing edges incorporated radar
absorbent materials. Conventional rudders were eventually exchanged for all-moving vertical stabilizers. The wingtips were rounded off, as well.