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. The J79 engines produced noticeable amounts of black smoke, a severe disadvantage in that the enemy could spot the aircraft. This was solved with a smoke-free combustor.
(Wikipedia)
LA=Barksdale AFB