Editing Manual command to line of sight (section)

{{Short description|Method for guiding guided missiles}}

'''Manual command to line of sight''' ('''MCLOS''' or '''MACLOS''')<ref>{{cite journal |last1= Iyer, N. R. |first1= |last2= |first2= |date=1995 |title=Recent Advances in Antitank Guided Missile Systems |url= https://core.ac.uk/download/pdf/333720993.pdf|journal=Defence Science Journal |volume=45 |issue=3 |pages=187–197 |doi= |access-date=}}</ref> is a method for guiding [[guided missile]]s.

With an MCLOS missile, the operator must track the missile and the target simultaneously and guide the missile to the target. Typically the missile is steered with a [[joystick]], and its path is observed through a periscope-type telescopic sight. The missiles are usually equipped with a [[magnesium]] [[flare]] in the base that automatically ignites on launch and allows the gunner to visually track the fast-moving missile in a manner similar in concept to [[tracer ammunition]].

MCLOS requires considerable training and practice to master, since even a minor disruption in the gunner's concentration would likely cause a miss. These guidance systems have marginal accuracy on tank-sized targets, even with perfect line-of-sight by the gunner, due to erratic flight paths requiring timely manual corrections. As demonstrated by the Israeli Army under fire from Soviet-armed Arab states, responding to the distinctive smoke puff of a missile launch with rapid manoeuvres and immediate counter-fire minimizes their accuracy, as very few [[anti-tank guided missile]] (ATGM) gunners maintain their concentration on a fast-moving tank for the entire flight time of the missile while under suppressing fire.

MCLOS guidance today has mostly been replaced by the easier-to-use [[semi-automatic command to line of sight]] (SACLOS), which allows the gunner to merely track the target with an optical sight (which guides the missile), rather than being forced to both visually track the target and fly the missile manually. The [[Vickers Vigilant]] attempted to solve this by using a "velocity control" method with an on-board gyroscope, rather than simpler "acceleration control".