YF-23A

The Northrop/McDonnell Douglas YF-23A PAV-2, on permanent static display at the National Museum of the United States Air Force (NMUSAF) at Wright-Patterson Air Force Base in Dayton, Ohio, remains one of the most visually striking aircraft ever to fly in American airspace. The airframe's distinctive diamond-shaped wing planform, trapezoidal fuselage cross-section, and canted all-moving V-tail surfaces reflect a design philosophy that prioritized low observable (stealth) performance and supersonic efficiency above nearly all other considerations. Powered by two General Electric YF120 variable-cycle engines during its flight test program in 1990 and 1991, PAV-2 demonstrated supercruise capability — sustained supersonic flight without afterburner — at speeds that reportedly exceeded those of its eventual competition winner, the Lockheed YF-22.

The YF-23 emerged from the Advanced Tactical Fighter (ATF) program, the U.S. Air Force effort launched in the early 1980s to develop a fifth-generation air superiority fighter to replace the F-15 Eagle. Two competing teams faced off: Northrop and McDonnell Douglas with the YF-23, versus Lockheed, Boeing, and General Dynamics with the YF-22. Both designs incorporated stealth shaping, advanced avionics, supercruise, and high agility requirements. The two YF-23 prototypes — PAV-1, nicknamed "Black Widow II" after the Northrop P-61, and the gray PAV-2, known as the "Gray Ghost" — flew a combined demonstration program before the Air Force selected the YF-22 in April 1991. The decision hinged largely on the YF-22's assessed advantage in maneuverability and perceived lower development risk, even as many analysts have since argued the YF-23 held edges in stealth signature and outright speed.

For professional aviators and aerospace operators, the YF-23's story is a master class in the tension between technical performance and programmatic factors that govern defense acquisition. The aircraft's defeat in the ATF competition did not reflect a failure of its aerodynamic or low-observable design; rather, it illustrates how factors including contractor experience, risk posture, and perceived operational flexibility routinely shape procurement outcomes. The YF-23's exhaust system — which used trench nozzles buried within the upper fuselage to cool and shield engine efflux from infrared detection — set a template for subsequent stealth exhaust management that influenced later programs, including unmanned combat air vehicles.

The NMUSAF's PAV-2 represents a broader curatorial value for the aviation community. Wright-Patterson has long served as the institutional memory of U.S. military aviation development, housing not only production aircraft but experimental and prototype types that illuminate the decision trees of advanced aerospace engineering. The YF-23's presence alongside aircraft like the XB-70 Valkyrie and SR-71 contextualizes the extraordinary range of aerodynamic solutions American industry explored across the jet age. For pilots operating modern stealth-adjacent platforms — from F-22 and F-35 operators to those flying business jets with reduced radar cross-sections — the YF-23 offers a tangible reference point for understanding how fifth-generation design principles were competed and refined before entering service.

The continued public interest in the YF-23, decades after its program cancellation, reflects a persistent fascination with roads not taken in aerospace development. In an era when next-generation fighter programs such as the F-47 and NGAD (Next Generation Air Dominance) are again shaping the future of air superiority, the YF-23 stands as a reminder that the best technical solution does not always prevail — and that the aircraft which lose competitions often carry forward ideas that resurface in subsequent generations of design.