Jun 052013
A late 1970’s/early 1980’s design for a supersonic transport from Lockheed included an unusual engine layout… two turbojets on the underside, two turbojets on the topside. This would certainly prevent shockwaves from the inlet spike of one engine from interfering with the inlet of another nearby engine, but it would also make the engines on the topside somewhat questionable during high-alpha (angle of attack) flight, such as takeoff and landing. Note that the drawing wa made with an early CAD program.
