> The idea that DARPA was ignorant of a fighter program by one of the largest weapons contractors in the country/world is absurd. It's a more nuanced story. W

> The idea that DARPA was ignorant of a fighter program by one of the largest weapons contractors in the country/world is absurd. It's a more nuanced story. What they didn't understand was that the A-12 series of aircraft (A-12, YF-12, SR-71 and even D-21) were specifically designed with early low observables principles & materials in mind. There was a lot of classification with these aircraft, particularly due to their initial customer (CIA rather than DoD). They needed to obtain permission from the CIA to discuss the low observables aspects with DARPA. These kinds of issues (inability to discuss relevant classified developments with other defense or intelligence entities that might benefit from knowing) is a routine and valid criticism of classification practice.