TACIT BLUE initially was created to demonstrate that a low observable surveillance aircraft with a low probability of intercept radar and other sensors could operate close to the forward line of battle with a high degree of survivability. Such an aircraft could continuously monitor the ground situation behind the battlefield and provide targeting information in real-time to a ground command center.
TACIT BLUE was one of the most successful technology demonstrator programs in Air Force history, meeting all program objectives and most low observable and sensor performance goals. The aircraft made its first flight in February 1982, and subsequently logged 135 flights over a three year period. The aircraft often achieved three to four flights weekly and several times flew more than once a day.
TACIT BLUE featured a straight, tapered wing with a "Vee" tail mounted on an oversized fuselage with a curved shape. It had a wingspan of 48.2 feet and a length of 55.8 feet and weighed 30,000 pounds. A single flush inlet on the top of the fuselage provided air to two high-bypass turbofan engines. TACIT BLUE employed a quadruply-redundant, digital fly-by-wire flight control system to help stabilize the aircraft about the longitudinal and directional axes.
The TACIT BLUE program cost approximately $165 million and covered development, construction and flight test. As the prime contractor, Northrop received a $136 million contract to provide one complete technology demonstrator and a partially-developed back-up airframe. The program provided valuable engineering data that aided in the B-2 "Spirit" design.