The "Tacit Blue" was built to test the advances in stealth technology. The aircraft made its first flight in February 1982 and by the conclusion of the program in 1985 had flown 135 times.
Northrop Tacit Blue on YOUTUBE
Specification
 
MODEL
"Tacit Blue"
ENGINE
2 x Garrett ATF3-6
WEIGHTS
Take-off weight
13500 kg
29763 lb
DIMENSIONS
Wingspan
14.69 m
48 ft 2 in
Length
17.0 m
56 ft 9 in
Height
3.23 m
11 ft 7 in
PERFORMANCE
Cruise speed
460 km/h
286 mph
Ceiling
9000 m
29550 ft
Comments
Richard Andersen, e-mail, 05.01.2015 00:37
I worked in the Advanced Projects Laboratory in Hawthorne on this project. I designed the Mission Computer Power and Control Console. It worked, as I was told by the operators. Later, I had the job of dismanteling it.
I worked for Northrop in their corporate flight dept. with Don Short. Dick Thomas did most of the experimental test flights on this and has passed away only a few years back. Dick's boss Hank Chouteau, whom I knew, passed away just a few weeks ago as of this writing (5 /10 /2014)
I worked on the ATF3 engine program from 1968 through 22000. The Tacit Blue had two Garrett ATF3 engines similar to the USCG ATF3-6-2C prototypes. In all five engines were delivered to Northrop with SN's 19101, 19102, 19103, 19104, and 19105. At the completion of the Tacit Blue program the remaining engines were sold to the USCG for spare parts and upgrades to ATF3-6-4C engines.
This now sits in the National Museum of the United States Air Force, at Dayton, Ohio. It looks kind of out of place amongst all the sleeker aircraft around it.