A hardpoint is any part of an airframe designed to carry an external load. This technical description includes mountings for engines, but most commonly the word is used to refer to the points on the wings of military aircraft where external stores - missiles, bombs, countermeasures, gun pods, and drop tanks - can be attached. Hardpoints on aircraft enhance the effectiveness of an aircraft but increase drag. By extension of the common usage, the word hardpoint is sometimes used to refer to a point on any vehicle where weapons or other accessories can be attached.
Mountings
Rather than being attached directly to the aircraft, most weapons use a mounting or pylon of some kind. This allows a standard hardpoint to carry a wide variety of weapons, which would otherwise need different fittings. It can also allow larger aircraft to carry many weapons on one hardpoint. Pylons for unpowered bombs are called "ejectors", and contain small explosive charges to push the bombs clear of the aircraft. Missiles with their own rocket engines are mounted on "rails" and clear the aircraft under their own power. A typical fighter aircraft will be fitted with a number of hardpoint mountings including bomb ejector racks, launch rails for missiles, and plumbed pylons for fuel stores.
Swing-Wing Aircraft
Swing-wing aircraft present a unique challenge because in order to minimize drag and maximize stability the hardpoints must swivel to present the least drag possible such as on the General Dynamics F-111, or the hardpoints must be placed on another part of the aircraft, such as on the F-14 Tomcat and Mikoyan MiG-27. Due to the limited number of hardpoints that could swivel on the F-111, not all hardpoints could be used if the plane was going to travel with fully swept wings.
