I have finished playing ace combat x: skies of deception and shooting it down is a pain in the ass. When playing AC:X, you have two mission choices sometimes and you have a mission to shoot down the Alect Squadron with their older aircraft, or do another mission and engage them on Fenrirs. When engaging them on their older aircraft, they are a bit hard to shoot down but eventually, you can shoot them down. When engaging them with Fenrirs, my tactic is to find one visibly, speed towards them head on with a lock and fire, firing from the front and fast makes it harder for them to evade. I call it "Supersonic Stab". I suggest any aircraft for this method but my choice are F-22, Adf-01 Falken and the Wyvern.