Hardpoint

A hardpoint is an attachment location on a structural frame designed to transfer force and carry an external or internal load.

The term is usually used to refer to the mounting points (more formally known as a weapon station or station) on the airframe of military aircraft that carry weapons (e.g. gun pods and rocket pods), ordnances (bombs and missiles) and support equipments (e.g. flares and countermeasures, targeting pods or drop tanks), and also include hardpoints (also known as pylons) on the wings or fuselage of a military transport aircraft, commercial airliner or private jet where external turbofan jet engines are often mounted.

For example, SEPECAT Jaguar has had some versions fitted with overwing hardpoints for air-to-air missiles directly above the innermost wing pylons, instead of putting them on the wingtips.

The pylons are automatically jettisoned if the wing sweep moves past 26 degrees, which would mean that the aircraft is accelerating towards transonic speeds.

The order can be for example from left to right (F/A-18 Hornet) or vice versa (F-15 Eagle), or mirrored and from outboard to inboard.

[3] The use of a pylon is necessary to clear the carriage item of control surfaces as well as prevent undesired disturbance of the flow of air toward the wing.

For example, in the Vietnam War, the "Wild Weasel" defense suppression version of the F-105 Thunderchief, the F-105G, could carry the usual AGM-45 "Shrike" anti-radiation missile on a standard pylon and launcher, but the newly developed AGM-78 Standard ARM required a specially designed and unique "LAU-78/a" launcher which was unique to that missile.

A military pylon provides carriage, deployment, and the ability to jettison external stores – weapons, pods, fuel tanks or other ordnance.

These adaptors can be bomb racks, launchers or other types of support structures each with their own provisions for mounting all other assemblies.

Depending on specific stores from 1,000 pounds (450 kg) upward, three or four lugs can be used within the defined suspension range.

A Multiple Ejector Rack (MER) usually refers to a support structure which enables the carriage of six stores.

A Triple Ejector Rack (TER) refers to a support structure which enables the carriage of three stores.

It is an extruded, machined aluminum member that provides structural rigidity to the launcher and includes provisions for mounting all other assemblies.

Aircraft such as the F-4 Phantom II, the F-18, and the Panavia Tornado ADV have semi-recessed fuselage stations to reduce drag.

The rapidly expanding gases, created by impulse cartridges, actuate ejector pistons and release the missile from the launcher.

Stealth aircraft such as the Chengdu J-20 use retractable launchers which moves out on rails allowing the weapons bay to be closed while still hanging outside.

A rotary launcher is a rotating suspension equipment mounted inside the bomb bay of a bomber.

Rotary launchers have stations of their own and offer the ability to select certain stores within the bomb bay for release.

For an external store emergency release, there is for example an emergency jettison button in the F-4 Phantom II, a feature found on all naval aircraft in case an engine or catapult fails during launch; in such cases, a pilot can press the "panic button", and jettison all stores, reducing weight and hopefully allowing the aircraft to avoid hitting the sea, and to climb away to decide on further action.