CHAPTER 5 - AIR-LAID MINES AND TORPEDOES

Since World War II, the U.S. Navy has developed sophisticated air-launched torpedoes and air-laid mines. These weapons incorporate components so sensitive that their operation is classified information. Therefore, the information in this TRAMAN on air-launched torpedoes and air-laid mines is limited. You will be referred to publications containing detailed information for the weapons discussed throughout the chapter.

MK 46 AND MK 50 TORPEDOES

LEARNING OBJECTIVE: Identify the purpose and use of the Mk 46 and Mk 50 torpedoes. Recognize the torpedo configurations to include warshot and exercise and aircraft-launched torpedoes. Identify Otto Fuel II.

The Mk 46 and Mods torpedo (fig.5-1) is the primary weapon used in antisubmarine warefare (ASW).

MK 46 TORPEDO CONFIGURATIONS

The Mk 46 Mods torpedo can be assembled into one warshot (tactical) and three REXTORP

Figure 5-1.-Mk 46 torpedo.

(recoverable exercise torpedo) configurations (fig. 5-2).

Mk 46 Warshot Configuration

The warshot configuration of the Mk 46 and Mods torpedo consists of a nose section, warhead control group, long fuel tank, and afterbody. A tactical warhead (contains explosives) is used in the warshot configuration.

Mk 46 Exercise Configuration

There are three versions of exercise torpedoes available for aircraft launching: (1) a torpedo with a short exercise head, extender section, and a short fuel tank; (2) a torpedo with a long exercise head and a short fuel tank; or (3) a torpedo with a long exercise head, instrumentation for tracking on 3D ranges, and a short fuel tank. All three configurations use Mk 85 and Mods exercise heads.

For detailed information concerning the component configuration of the Mk 46 and Mods torpedo, you should refer to Mk 46 Torpedo/Mk 46 REXTORP Flight Accessories (Description, Operation, Installation, Removal, and Trajectory Data), NAVSEA SW512-AO-ASY-010.

Mk 50 Torpedo

The Mk 50 (fig. 5-3) is a lightweight, high-speed, antisubmarine torpedo that is compatible with all airborne ASW platforms. It has improved design features to ensure greater reliability and increased capabilities over previous torpedoes. The three major sections of the torpedo are nose, head, and afterbody. The nose contains the transmitter and receiver. The afterbody provides propulsion and control. The exercise head provides buoyancy for the torpedo. The warshot head contains an explosive charge. The exercise torpedo is identified by an orange nose and afterbody with a 6-inch blue strip around the circumference of the ballast assembly. For further information on the torpedoes, you should refer to United States Ammunition Historical and Functional Data, NAVSEA SW010-AB-GTP-010.

AIRCRAFT-LAUNCHED TORPEDO CONFIGURATIONS

To air-launch torpedoes, you will use launch accessory equipment. This equipment includes suspension bands to attach the torpedo to the aircraft and torpedo air stabilizers to ensure a predictable air trajectory and water entry. Torpedoes are configured and issued to the fleet depending on tactical or training requirements. As an Aviation Ordnanceman (AO), you are not responsible for the assembly of the torpedo at the organizational level. However, you are responsible for the installation of launch accessory equipment.

Figure 5-2.-Mk 46 recoverable exercise torpedo (REXTORP).

Figure 5-3.-Mk 50 torpedo configurations.

The physical characteristics, such as weight, length, etc., of the Mk 46 torpedo vary. These characteristics depend on the configuration of the torpedo itself (warshot or exercise) and the configuration of the attached launch accessories. The Mk 46 torpedo is configured with aircraft-launch accessories for either helicopter or fixed-wing aircraft launching.

The basic items of accessory equipment used in launching torpedoes from fixed-wing aircraft and helicopters are the torpedo air stabilizer and suspension band assembly. The torpedo air stabilizer ensures a predictable air trajectory and water entry without torpedo structural damage. The air stabilizer reduces the descent speed of the torpedo relative to the speed of the launching aircraft. A static line or release lanyard deploys the parachute when the torpedo is dropped from the aircraft. The deployed parachute stabilizes the torpedo during descent to the water, slows the descent speed to an acceptable velocity for water entry, and assures the proper water entry angle. The

Figure 5-4.-Mk 28 Mod 2 torpedo air stabilizer.

Mk 28 Mod 2 (fig. 5-4) or the Mk 28 Mod 3 (fig. 5-5) air stabilizers are used on torpedoes configured for fixed-wing aircraft. The Mk 31 Mod 0 (fig. 5-6) or the Mk 31 Mod 1 (fig. 5-7) air stabilizers are used on torpedoes configured for helicopters.

Mk 78 Mod 0 or Mod 1 suspension bands (fig. 5-8) are used in pairs to suspend the torpedo from the bomb racks or shackles of the launching aircraft. The bands wrap around the torpedo and are secured by tension

Figure 5-5.-Mk 28 Mod 3 torpedo air stabilizer.

bolts. After the bands are installed, the torpedo is loaded aboard by engaging the suspension band lugs in the bomb racks or on the bomb shackles of the aircraft. The torpedo is loaded internally for fixed-wing aircraft launch and externally for helicopter launch. When the bomb rack/shackle hooks are released, the torpedo drops. Release wires unlatch the suspension bands, allowing them to break away from the torpedo as it is launched from the aircraft.

Figure 5-6.-Mk 31 Mod 0 torpedo air stabilizer. 5-4

Figure 5-7.-Mk 31 Mod 1 torpedo air stabilizer.

Figure 5-8.-Mk 78 Mod 0 and Mod 1 suspension band assemblies. 5-5

For detailed information concerning aircraft launch accessories, you should refer to the U.S. Navy Aircraft Torpedoes Accessories and Trajectory Data and Quality Assurance Test and Inspection Plan for Installation of Torpedo Mk 46 Launch Accessories, NAVSEA SW512-AO-ASY-010.