Editing Torpedo (section)

===Pattern running===
[[File:Flachenabsuchender_Torpedo_type_I_-_running_pattern.svg|thumb|right|The functional concept of torpedoes running a ladder search pattern, launched by two submarines at a moving convoy.]]
During the Second World War, the Germans introduced programmable pattern-running torpedoes, which would run a predetermined pattern until they either ran out of fuel or hit something. These weapons would generally engage in a [[Water surface searches#Parallel track|ladder search pattern]], and were intended for engaging [[Convoy|convoys]] of vessels, commonly encountered in the Atlantic theater. The use of pattern-running torpedoes allowed a [[Wolfpack (naval tactic)|wolfpack]] of U-boats to lob large numbers of shots in the general area of a moving convoy, without concern that two different U-boats may be targeting the same vessel.

The earlier version of the weapon, FaT (''Flächenabsuchender'' - "planar seeker"), ran out after launch in a straight line, and then weaved backward and forwards parallel to that initial course, whilst the more advanced LuT (''Lageunabhängiger'' - "position-independent") could transit to a preprogrammed gyrocompass angle after reaching a set distance after launch, and then enter a more complex weaving pattern.<ref>{{cite web | title = U-boat Archive – Interrogation of U-Boat Survivors – Cumulative Edition | url =http://www.uboatarchive.net/KTB/KTBNotesArmamentCumulativeEdition.htm | access-date = 2017-04-13}}</ref>

Germany also used the Italian [[List of World War II torpedoes of Germany|LT 350 aerial torpedo]] for [[Anti-submarine warfare|ASW]]. The weapon lacked an acoustic seeker head, but it would be dropped in clusters over the approximate location of a lurking enemy submarine, and would thereafter engage in a chaotic movement pattern, in order to hit the target by random chance.

A somewhat similar concept for a chaotic underwater pattern search was experimented with by Japan during the Second World War with their [[Japanese 45 cm torpedo#Bomb-Torpedoes|Kūrai No.6 and No.7]] circling ASW bomb-torpedoes. These weapons did not possess homing capabilities, nor a propulsion system; the design resembled a [[Dart_(missile)|dart]], and would glide at high speed when launched. The functional concept envisioned multiple such weapons launched directly by an aircraft at a surfaced submarine, or at the approximate location of a submerged one. After splashdown, the weapons would move in a spiral pattern as they sank, their forward movement being enacted by the Earth's gravity.

Acoustic homing torpedoes usually possess the capability to engage in simple search patterns at the launching entity's discretion; the most common of these are the snake (weave left and right while moving forward, to achieve a wider forward-facing detection cone) and the circle (continuously travel in a circle, for omnidirectional detection around the epicenter of the circle) search patterns. A good example of a weapon possessing both of these search patterns is the [[Mark 46 torpedo|Mark 46]] lightweight torpedo, used in large numbers worldwide.