Lock-on after launch

Lock-on after launch, or LOAL, is a capability of missile systems to lock-on to its target after being launched from its carrier vehicle. The term is normally used in reference to airborne weapons, especially air-to-air missiles. LOAL is an important part of modern weapon systems as it allows the weapons to be carried internally to increase stealth and then acquire the target once it has left the launching aircraft. LOAL systems normally rely on cuing from a helmet mounted sight or onboard sensors like radar or FLIR, and use a simple strapdown inertial guidance system to know where to look after launch. Examples of LOAL weapons include the ASRAAM air-to-air missile and later versions of the AGM-114 Hellfire anti-tank missile. The older method of launch has retroactively become known as lock-on before launch, or LOBL, although this term is not commonly used and is a backronym to distinguish it from LOAL method.