The F-15C, with avionics updated over the 'A' model, is the current front-line air superiority fighter of the United States Air Force. It adds FAST (fuel and sensor, tactical) conformal fuel tanks that fit flush against the sides of the fuselage and greatly increase internal fuel load with no extra drag. The radar has also been replaced by the newer, more powerful Hughes APG-70 system. Available since 1980, it is a significant improvement over the original 'A' model Eagle except the new equipment makes the aircraft heavier. [See also F-15A]
