An aggressor squadron or adversary squadron (in the US Navy and USMC) is a squadron that is trained to act as an opposing force in military wargames. Aggressor squadrons use enemy tactics, techniques, and procedures to give a realistic simulation of air combat (as opposed to training against one's own forces). Since it is impractical to use actual enemy aircraft and equipment, surrogate aircraft are used to emulate potential adversaries. The first formal use of dissimilar aircraft for training was in 1969 by the Navy Fighter Weapons School (better known as "Topgun"), which used the A-4 Skyhawk to simulate the performance of the MiG-17. The success of formalized dissimilar air combat training (DACT) led to transition of Navy Instrument Training Squadrons equipped with the A-4 into Adversary Squadrons at each Master Jet Base. The USAF followed suit with their first Aggressor squadrons at Nellis AFB equipped with the readily available T-38 Talon. Origins In the Second World War, the antagonists captured each other's aircraft and introduced them into a modest DACT role. The Germans created a unit known as "Touring Zirkus Rosarius" with captured P-51s, P-47s etc. that visited fighter bases and even let the senior pilots fly the adversary aircraft themselves. The RAF created No. 1426 Flight RAF with Luftwaffe captured fighters (Bf-109s and FW-190s) that were fully tested and then taken to USAAF and RAF bases for familiarization training. Aggressor aircraft used in the United States Domestically-made aircraft US aggressor squadrons fly small and low-wing loaded fighters that are used to represent those of the potential adversaries. Originally Douglas A-4s (US Navy) and Northrop F-5s (US Navy, Marines, and Air Force) were flown along with T-38 Talons that were immediately available and served as placeholders until new F-5E/F Tiger II aircraft were introduced. These were eventually supplemented by early-model F/A-18As (US Navy) and specially built F-16Ns (for the US Navy) and F-16A models (for the Air Force). At the end of 2005, the USAF started using the larger and faster F-15 Eagle as an aggressor aircraft alongside the F-16 at Nellis Air Force Base. However, the USAF began phasing out its F-15 aggressors towards the end of 2014. With the deactivation of the 65th Aggressor Squadron, the F-16C is once again the only dedicated aggressor type at Nellis AFB until 2022, when the 65th was reactivated with the F-35A Lightning II to better simulate stealth fighter threats. Foreign-made