AERIAL ANTI-SUBMARINE WARFARE

[Music] [Music] [Applause] [Music] because of speed aircraft are capable of making surprise attacks on surface submarines at sea but the ability of the submarine to dive and maneuver underwater means that the pilot after making contact usually has only seconds in which to decide on his method of attack select his weapons and fire weapons that can be carried include rockets depth bombs and homing torpedoes loading will vary with type of aircraft area of operation intelligence and squadron doctrine pilots must know what weapons are carried in the aircraft their characteristics their uses and their loading with reference to the selector switch because the proper weapon will have to be selected for use according to the kind of attack being made let's review briefly the weapons capabilities typical anti-submarine rockets carried by aircraft have solid steel heads designed to penetrate the pressure hull of the submarine to sink or it the depth bombs are hydrostatically fused and are set to explode at a desired depth the flat nose prevents ricochet when the bomb strikes the water it also slows sinking time and makes the underwater trajectory more uniform two types of torpedoes may be carried one is passive that is it homes on submarine noises it is electrically driven and has a search speed of 12 knots and an attack speed of 18 knots the other type of torpedo is active electrically driven it homes to the target by echo ranging its search and attack speeds are the same 15 knots and its endurance is from 7 to 11 minutes there are five classes of aerial attack known as early tardy late visible and blind they are employed in the various technical situations encountered in normal anti-submarine operations the weapons used are aircraft rockets depth bombs and homing weapons their selection depends on the kind of attack to be made selection is shown for both day and night attacks this film will show and describe the aircraft tactics used in the various kinds of attacks an early attack can be made when the submarine is surfaced or is diving with at least some part of it still visible above the surface at the time of the attack a tardy attack is made within 10 seconds after the submarine has disappeared under the surface a late attack is made when the submarine has been submerged from 10 to 20 seconds at the time the weapons are fired the term visible attack applies to those situations in which the circle of the submarine is visible or rare cases in which the submarine silhouette under the surface is seen by the pilot of the aircraft the former is similar to the tactical situation in an early attack if the submarine has submerged more than 20 seconds before the attack can be delivered or if contact is made by any means other than visual such as by mad a blind attack must be made when an aircraft makes daylight contact with a surface submarine and the pilot knows that if the submarine dives he can make an attack while some part is still visible he will use rockets a 15 degree angle of attack has been found to be effective in most cases depending on altitude and speed for a rapid computation of range the altitude in feet will indicate the slant range in yards for this angle thus range can be estimated by altimeters the pilot will try to come in between 225 and 315 degrees from the beam or between 135 and 45 degrees for his attack because at any greater angle the rocket might ricochet on striking the target his best approach is at 90 degrees to the submarine for at this angle the projectile will penetrate best when it strikes at any range between 1200 and 800 yards the first rockets may be fired the shorter range is better if the attack can begin before the submarine has submerged the rockets should be aimed to enter the surface 20 feet short of the water line below the conning tower because of their velocity however they are effective up to approximately 130 feet of underwater travel they travel at shallow depth at approximately 15 feet so our value only against the surface or partially surfaced target this aircraft is searching in a submarine probability area the pilot knows his weapons carried and the loading he gets visual contact on a surface submarine he quickly maneuvers to the proper approach angle and begins his descent at the same time estimating the range and deciding whether he can attack before the submarine becomes completely submerged if it dies with time to attack while the submarine is still partially surfaced he decides on an early attack and carefully sets his selector switch for rockets within 1200 yards range and before reaching 800 he fires two rush these will help him correct his aim for further firing and he maneuvers as necessary and as time permits for best results he again fires two at 800 yards another two at 600 yards and saves his remaining rockets to fire in a ripple at 400 yards range with proper aim at least some of these rockets will enter the water 20 feet short of the target and penetrate the pressure hull of the submarine that was an early attack with at least part of the submarine visible the snorkeling submarine also offers an opportunity for early attack if the pilot can attack very quickly he might use rocket or depth bombs in a nice early attack note that death bombs are first choice the term visible attack is used to describe a situation in which the submarine although submerged is visible homing weapons are first choice and depth bombs second choice for this kind of attack this situation occurs when the pilot sees a submarine under the surface if he flies over he will probably not see it again conditions of light ocean surface and flight direction must be just right if the attack cannot be delivered immediately the pilot must mark the spot with a smoke marker drop his son a boy and then plan further localization or attack from the information he received a tardy attack is made when the pilot believes he can attack within 10 seconds after complete submergence of the submarine depth bonds are first choice either day or night if the approach is made from for or after the target it should be made within 15 degrees of the fore and aft line to obtain the best results while this approach will minimize range error it should not be chosen at the expense of a direct approach depth bonds should be released at an altitude of 100 feet or lower if practicable except in a glide attack when release should be made from the lowest altitude which will permit a safe recovery the bonds should be aimed ahead of the swirl at a distance depending upon estimated submarine speed and time since it submerged in the direct approach the purpose is to obtain a straddle and to place at least one bomb to explode close aboard the cunning tower or within the lethal radius this means within 22 feet of the submarine it will still do major damage up to 40 feet away and minor damage up to 70 feet [Applause] on making contact and deciding on a tardy attack the pilot heads for the target and descends to the best altitude for the attack he has only moments in which to set his selector switch and make the attack the recommended spacing for depth bombs is 70 feet 60 to 80 feet may be used depending on the aircraft's angle of drive altitude and air speed the pilot also considers diving speed of the target the usual forward diving speed is 10 feet per second this will vary however with different submarines if the pilot has only four to six bombs he will usually attack with the whole stick with more bombs he will save some for a second attack while watching for signs of a kill the planet starts tracking the submarine with mad or sono boys if he has more bombs he may use them or a homing weapon either active or passive depending on mad or sono boy information of the submarine's course and speed the homing weapon is second choice in a tardy day attack but is first choice at night however a diving submarine generates much noise and a passive homing weapon has a good chance of success in a late attack the submarine will have been completely submerged from 10 to 20 seconds before the weapons can be launched for this reason homing weapons are first choice because the submarine is known to be diving and will probably be cavitating the pilot will use a passive torpedo after entering the water the passive torpedo will search at 12 knots until it hears cavitation or other noises made by the submarine it will hold on the sound source and then attack the submarine at 18 knots the aircraft is searching the pilot makes a contact on a diving submarine estimating that it will have been submerged from 10 to 20 seconds before he can attack he maneuvers to altitude and position for a late attack if he does not attack on the first pass over the datum he immediately tries to establish mad contact because this offers the most reliable source of information for fire control and permits placement of the weapon well within its target acquisition range when possible he places the weapon slightly ahead of the target for greater hit probability he also drops the sauna boy to assist in post-attack analysis by recording the sound of torpedo explosion while listening to the son of boy to learn whether the attack was successful the operator continues to track with mad unless the pilot has made a kill he will attack with another homing weapon or maintain contact until assistants arrive homing weapons are first choice for the late attack either day or night depth bombs are second choice when target contact is made by any means other than visual a blind attack will be made with homing weapons blind attack means that the submarine will have been completely submerged for more than 20 seconds before a weapon can be dropped or that it was already submerged when contact was made by sono boys or mad with mad contact established the pilot flies a normal mad cloverleaf pattern to determine the submarine's track before dropping a homing weapon in most cases three marked contacts are sufficient for this purpose after estimating the submarine speed from sonic boy information the pilot must select the proper weapon a passive torpedo if the submarine is cavitating an active torpedo if the speed is very slow this aircraft has made contact on a submerged submarine and the pilot has dropped a sonoboy he has mad contact and is flying a normal cloverleaf tracking pattern to establish the submarine's trap on each mad contact the pilot drops a smoke marker the estimate of target speed is derived from both mad and sonoboy information finding that the submarine speed is slow he decides to use an active torpedo and sets his selector switch accordingly he has made three mad contacts and is now starting the attack when he gets a fourth mad contact he drops a torpedo properly launched the active torpedo finds its mark the pilot continues tracking until signs of the kill are obtained otherwise he will attack again using either a passive or active torpedo depending on the tactical situation we have discussed the main points of aerial anti-submarine warfare let's review them briefly for successful aerial anti-submarine operations pilots must know what weapons are carried they're loading with reference to the selector switch their characteristics and their uses in different kinds of attacks then they must understand the classes of attack and the selection of the proper weapons for each tactical situation an early attack is delivered when at least some part of the submarine is still visible above the surface rockets are first choice in day attacks depth bombs are first choice at night a tardy attack is made within 10 seconds after the submarine has completely submerged death bombs are first choice day or night a homing weapon is second choice in day attack or may be used instead of bombs at night if the submarine has been submerged from 10 to 20 seconds a late attack is made with homing weapons first choice day or night depthbond's second choice visible attack means a situation in which the submarine's snorkel is visible or the rare situation in which a silhouette of the submarine is seen under the surface foaming weapons or depth bombs may be used when the submarine has been submerged longer than 20 seconds a blind attack is made the pilot tracks with mad and sauna boys homing weapons will be used in both day and night attacks rocket firing may begin at ranges up to 1200 yards the best approach is at 90 degrees to the target they should be aimed to strike 20 feet from the water line a direct approach is recommended for attack with depth bombs however if this is not possible the attack should be made within 15 degrees of before and aft line of the submarine this offers a high probability of success as it tends to minimize range error bombs should be placed so at least one will fall within the lethal radius of the target 22 feet although they will do damage up to 70 feet away the passive torpedo is used in attack on a cavitating submarine the highest percentage of hits will be obtained when a torpedo is dropped to fall ahead of the submarine along its projected track the active torpedo should be dropped on mad signal or as close as possible to the submarine aircraft are effective against submarines when weapons are properly selected for the tactical situation and when attacks are made from the proper altitudes angles and ranges for the type of weapons used if you are a pilot it is your job to know that [Applause] [Music] you