“Be secret and exalt, because of all things known, that is most difficult” – when the poet Yeats wrote that early this century, he couldn’t have dreamt, how true that would be for a group of dedicated aerospace professionals in the pursuit of the advancement of technology.
It is difficult to imagine achieving a unique level of accomplishment and not being able to express it. But those were the rules then.
In the late 1970s the United States was committed to a policy of détente with the former Soviet Union. While the Soviets spoke of arms control they deployed massive conventional forces posing a serious threat to global security. To counter this potential danger the United States adopted the strategy of employing superior surveillance technology and techniques.
In 1978 the then Northrop corporation received a contract to meet this technological challenge head-on. The classified project was so shrouded in secrecy that at one time the US Air Force claimed that it would never be revealed to the public. It was given the code name Tacit blue.
“We were giving a very challenging task so that the whole program was exciting and it’s hard to break out what’s most exciting in. Working with a very talented group of people as a team, there’s a lot of camaraderie.” – Irv Waaland
“Well I believe we did aviation history and I believe that the airplane would say for historical reasons and I imagined that someday this was hat would happen. In fact I wish it had happened a few years earlier. It’s there are people that should share in this that are now deceased and they should… it’s a great day for all it works on the airplane.”
Tacit Blue tested the very latest advances in aviation stealth technology. The Air force, Defense Advanced Research Projects Agency (DARPA) and Northrop aircraft ultimately proved that curved surfaces could result in low radar return from ground radar.
“It’s the aerodynamics of the vehicle that are so different from anything else because the airplane is aerodynamically unstable in yaw and pitch. So as a result you have to have a computer-controlled flight control system which gives you the flying qualities of the airplane.” – Dick Thomas, Tacit Blue project test pilot
With the stealth features first demonstrated by Tacit Blue an aircraft could safely operate close to the battlefield forward line with minimum fear of detection, while sending vital information to ground command centers.
Tacit Blue proved that a stealthy aircraft could have curved surfaces unlike the faceted surfaces of the F-117 Nighthawk which greatly influenced later aircraft like the B-2. Tacit Blue’s design also minimized the heat signature emitted from the engines, further masking its presence. Tacit Blue was aerodynamically unstable, but it had a digital fly-by-wire system to help control it.
With its low, “all-aspect” radar signature, Tacit Blue demonstrated that such an aircraft could loiter over and behind the battlefield without fear of being discovered by enemy radar. Using advanced sensors, it could also continuously monitor enemy forces (even through clouds) and provide timely information through data links to a ground command center. Moreover, these sensors functioned without giving away the location of the aircraft.
First flight for the “Whale” took place, Feb. 5, 1982, and it was not the easiest vehicle to fly. The Tacit Blue aircraft flew 135 times before the program ended in 1985. The aircraft often flew three to four flights weekly and several times flew more than once a day. After reaching about 250 flight hours, the aircraft was placed in storage in 1985.
Tacit Blue did not go into service as its battlefield surveillance role was given to a standoff platform based on a commercial airline design. Using the sensor systems developed for Tacit Blue, the E-8 Joint Surveillance Target Attack Radar System, or Joint STARS, came to be.
Tacit Blue was declassified and placed on display at the museum in 1996.
On May 22nd 1996, the US Air Force unveiled the Tacit Blue aircraft in a ceremony where many of the program’s key contractor supplier and government personnel received the recognition they long deserved.
Affectionately known as the whale it resembled the plane joined other historic aircraft in one of the most spectacular aerospace museums in the world – the U.S. Air Force museum in Dayton, Ohio.
Although only a few people were able to attend the Tacit Blue ceremony others were there in spirit. The hundreds of Northrop Grumman employees subcontractors and customers who dedicated many years to this program.
After enduring years of a silent Odyssey set adrift on strange seas, this Whale and her whalers are finally recognized and home at last displaying for the future their spirit of innovation.
Tacit Blue’s stealth philosophy has been used in almost every stealth aircraft in existence today. Thanks to this unusual aircraft, we came a long way to modern stealth fighters and bombers.
Tacit Blue technical notes:
Crew: One
Engines: Two Garrett ATF3-6 high-bypass turbofan engines
Design operational speed: 287 mph/250 knots
Operating altitude: 25-30,000 feet
Weight: 30,000 lbs.
photos- National Museum of the USAF
