 In air combat , the Phantom 's greatest advantage was its thrust , which permitted a skilled pilot to engage and disengage from the fight at will . The massive aircraft , designed to fire radar @-@ guided missiles from beyond visual range , lacked the agility of its Soviet opponents and was subject to adverse yaw during hard maneuvering . Although thus subject to irrecoverable spins during aileron rolls , pilots reported the aircraft to be very communicative and easy to fly on the edge of its performance envelope . In 1972 , the F @-@ 4E model was upgraded with leading edge slats on the wing , greatly improving high angle of attack maneuverability at the expense of top speed . 
