US Air Force begins separation testing of Stand-in Attack Weapon

An F-16 from Eglin AFB drops an inert Stand-in Attack Weapon for the first time on 7 November over the Gulf of Mexico. (USAF)

The US Air Force (USAF) began separation testing of the Northrop Grumman Stand-in Attack Weapon (SiAW), according to a 2 December statement by the service.

Separation tests began on 7 November, when a Lockheed Martin F-16 assigned to the 40th Flight Test Squadron at Eglin Air Force Base (AFB), Florida, released an inert missile body over the Gulf of Mexico. Separation testing is a standard flight test to ensure that the missile can separate cleanly from the aircraft, emerging from its slipstream without difficulty.

SiAW is designed to detect and strike rapidly relocatable targets, including missile launchers and electronic jamming platforms, according to the USAF. It contains an anti-radiation homing seeker and is likely to be employed primarily to suppress or destroy enemy radars and air defences. The missile is designed for carriage within the internal bays of the Lockheed Martin F-35, allowing the stealth aircraft to strike high-priority targets while remaining distant from threats.

The missile is closely related to a similar US Navy programme, the Advanced Anti-Radiation Guided Missile – Extended Range (AARGM-ER). SiAW is intended to complement the dedicated High-speed Anti-Radiation Missile (HARM) and AARGM-ER.

Although neither Northrop Grumman nor the USAF has released SiAW's specifications, the AARGM-ER upon which it is based boasts an estimated range of 140 miles (225 km), according to Janes Weapons: Air-Launched database.