Prototype Information: YF-23 "Black Widow" The YF-23 was the losing aircraft in a two plane "fly-off" to develop the air superiority fighter of the 21st century for the USAF. It would have replaced the F-15 Eagle. The aircraft has been designed using next generation "Stealth" technology to make radar detection difficult and it is also aerodynamically efficient being able to cruise at supersonic speeds without afterburner which has been termed "supercruise". Unlike its conventional tailed competitor, the YF-22, the YF-23 features a V-tail.