Millstone

Millstone is the service name of the ASM-43 Bracken precision surface weapon. Its controlling equipment identity, production period and authorised aircraft use are recorded in Aviation Manufacturing and Systems. The weapon entered production in 1984 for the A-43 Dart and NS-44 Cutlass.

Role and construction

The missile is used against armoured vehicles, fortified structures and other high-value surface targets. Short- and extended-range configurations use a common 3.5-metre airframe, 0.3-metre body and 200-kilogram multi-purpose tandem warhead. Depending on launch height and route, the two configurations have nominal ranges of 50 and 120 kilometres and fly at approximately Mach 0.9 to Mach 1.2.

SkyNet Systems is design and integration authority. Millstone Defence Systems supplies the warhead and propulsion section under contract, AeroFlux Dynamics supplies control actuators, and FrictionLess Technologies supplies low-observable surface treatments. SkyNet retains responsibility for guidance software, aircraft interfaces, acceptance testing and configuration control.

Guidance and employment

The guidance package combines inertial navigation with satellite updates and terminal laser or satellite-coordinate guidance. A secure data link permits route or target updates before terminal attack. Crews may select a direct, shallow or steep terminal approach according to the target and surrounding terrain. The extended-range configuration can hold in a pre-planned subsonic orbit for up to ten minutes while the crew confirms a target. The missile can be released from 100 to 5,000 metres above ground level; its practical launch envelope is governed by the aircraft's target-quality data, weather and rules of engagement rather than range alone.

The weapon does not attack several targets in one flight. A Dart may instead carry and programme several missiles, each assigned to one target or aim point. Post-launch control is available when the mission requires confirmation or a change of aim point, while a validated fixed target can be engaged without continuous crew guidance.

Service use

Dart crews use Millstone for precise attacks where unguided weapons would impose excessive risk or where a target must be struck from beyond local air defences. The weapon's association with the aircraft reflects the Dart weapon-systems officer's ability to confirm targets, assess collateral risk and manage more than one weapon during a sortie. Naval NS-44 crews used the same equipment identity with naval handling and corrosion-control procedures.