The USAF issued a request for information (RFI) to industry on January 8 for its stand-in attack weapon (SiAW) requirement for an internally-carried long-range weapon for the F-35A Lightning II.

The SiAW program seeks to develop an anti-access/area denial (A2/AD) air-to-surface capability based on the developmental Northrop Grumman AGM-88E Advanced Anti-Radiation Guided Missile-Extended Range (AARGM-ER) program. But SiAW will have a broader target set than the anti-radiation AARGM-ER, and will reportedly employ an active radar homing guidance system, different warhead and fusing, and a universal armament interface (UAI).

The UAI will allow for the uploading of targeting coordinates or aircraft sensor information in flight in order to be able to attack and defeat mobile targets in an A2AD environment. These could include theatre ballistic missile and cruise, and anti-ship missile launchers, GPS jammers, anti-satellite systems, and integrated air defence systems (IADS).

As the threshold launch platform the SiAW will be able to be carried in the F-35A/C weapons bay. But it is possible it will also be carried internally by the B-21 Raider, and externally by other types such as the F-16CG/J and F-15E. The AARGM-ER will reportedly have a range of up to 200km depending on launch profile, but no range requirements for SiAW have been publicly revealed.