 Changes in operational use and additional systems have increased weight, necessitating multiple structural strengthening programs.The F-16 has a cropped-delta wing incorporating wing-fuselage blending and forebody vortex-control strakes; a fixed-geometry, underslung air intake (with splitter plate) to the single turbofan jet engine; a conventional tri-plane empennage arrangement with all-moving horizontal "stabilator" tailplanes; a pair of ventral fins beneath the fuselage aft of the wing's trailing edge; and a tricycle landing gear configuration with the aft-retracting, steerable nose gear deploying a short distance behind the inlet lip.There is a boom-style aerial refueling receptacle located behind the single-piece "bubble" canopy of the cockpit.