The United States Air Force (USAF) and United States Navy (USN) are anticipated to field their first sixth-generation fighters in 2025–2030.[1] The USAF is pursuing development and acquisition of a sixth-generation fighter through the Penetrating Counter Air[2] to replace its existing air superiority aircraft such as the McDonnell Douglas F-15 Eagle and complement existing platforms in service such as the Lockheed Martin F-22 Raptor. The USN is pursuing a similar program called the Next Generation Air Dominance, likewise intended to complement the smaller Lockheed F-35 and replace its existing aircraft such as the Boeing F/A-18E/F Super Hornet.[3]