The Curtiss Lark model 41 was the follow-on aircraft, employing 4 interchangeable wing panels.
This effort ultimately proved unsuccessful, and work began on a follow-on aircraft, which resulted in the Lockheed A-12 Oxcart.
The number of electric motors was increased to eight, and the motors used were more powerful units, designed for the follow-on aircraft.
All 370 of the follow-on aircraft, the Boeing B-50 Superfortress, were built in Plant 2.
By designing in anti-radar features from the beginning, it was hoped that the follow-on aircraft would escape detection.
Had the program progressed, follow-on aircraft would have been based on the successor to the B-36, Convair's swept-wing B-60.
This concept works only if the Pathfinders correctly mark the town and the follow-on aircraft can see the marker bombs.
The follow-on aircraft to replace the A320 was rumored to be named A30X.
When this was unsuccessful, he initiated GUSTO to develop a follow-on aircraft.
In 2005, Gulfstream began designing a follow-on aircraft.