The Man Who Helped Test Both the F-15 Eagle and F-117 Stealth Fighter Has Passed Away

August 23, 2019 Topic: Security Blog Brand: The Buzz Tags: F-117MilitaryTechnologyWorldF-117

The Man Who Helped Test Both the F-15 Eagle and F-117 Stealth Fighter Has Passed Away

A true legend. 


On Aug. 15, 2019 Norman “Ken” Dyson, a U.S. Air Force (USAF) and civilian test pilot most noted for his work on the “Have Blue” and “Tacit Blue” experimental stealth aircraft, died at 81.

As told by Air Force Magazine, Dyson was a fighter pilot who became a test pilot. After having flown the F-100 and F-4 in the Vietnam War, he returned to serve as an Air Force test pilot, where he flew weapons development tests in F-100, F-101 and F-4 aircraft, and as an F-15 test pilot during its early days. He became director of the F-15 Joint Test Force, then the Air Force’s highest-priority combat aircraft program.


He began work on top-secret programs, including the Lockheed “Have Blue” stealth demonstrator that led to the F-117 Nighthawk, the first stealth attack jet, in 1976. Dyson was flying Have Blue No. 2 in July 1979 when an engine fire caused a violent oscillation of the fly-by-wire aircraft, forcing him to eject. The jet was destroyed but Dyson survived and went on to fly the Northrop “Tacit Blue.”

Built in the early 1980s in great secrecy, the revolutionary Tacit Blue aircraft tested advanced radar sensors and new ideas in stealth technology.

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.

After Dyson retired as a lieutenant colonel, he went to work for Rockwell (now part of Boeing), and flew the B-1 bomber through much of its test program. Dyson flew the X-31 Enhanced Fighter Maneuverability demonstrator too. A multinational project with Germany to explore post-stall flight the X-31 was test-flown during the early 1990s at NASA’s Dryden Flight Research Center, Edwards, CA, to obtain data on control in the post-stall flight regime. The X-31 program demonstrated the value of thrust vectoring – directing engine exhaust flow – coupled with advanced flight control systems, to provide controlled flight at very high angles of attack.

Dyson retired from Rockwell as its chief test pilot and director of flight test in 1993.

For his Air Force combat and test flying, Dyson received the Legion of Merit, two awards of the Distinguished Flying Cross, and nine Air Medals, among other decorations. 

A member and one-time president of the Society of Experimental Test Pilots, Dyson was also named an Engineering Fellow of the University of Alabama, Distinguished Aerospace Engineering Alumnus of the Texas A&M University, and a Distinguished Alumnus of the USAF Test Pilot School. 

Dyson received the SETP’s Iven C. Kincheloe award—its highest honor, awarded by peers—in 1989 for his work on Have Blue, and received it again in 1996 for his work on Tacit Blue (retroactive to 1982), when those programs were, respectively, declassified. In 1997, he was named to the Aerospace Walk of Honor in Lancaster, Calif.

This first appeared in Aviation Geek Club here