Auxiliary Equipment


The equipment described in this section is the auxiliary equipment used for the accomplishment of the drone mission. This section does not include a description of the special tools and test equipment required for the maintenance of the drone.



The motor- generator is an auxiliary power unit which supplies electrical power to the drone, prior to launching, through the AFC set umbilical cable. The generator is similar to the one installed on the drone and may be of the adjustable or nonadjustable type. The auxiliary generator is driven by an electric motor and variable speed drive. Generator speed is controlled by an external crank handle on the drive unit, and is monitored by a meter calibrated in cycles per second.

Nominal output of the generator is as follows:  

115 volts, 400 cps, phase A, B, C.

        22 volts, 400 cps, phase 1, 2, 3.

        26 volts, 400 cps, phase A, phase A-90 degrees.

The motor -generator is started and stopped by a local START-STOP control, which incorporates a circuit breaker.



    During heavy weather operations, the drone is transported between the hangar and the launching and landing area by means of a launcher -retriever system. The system includes restraint cables, restraint roller assemblies, handling wheels, towing cables and bridles, and a towing winch. (See figure 1.) The restraint roller assemblies are attached to the four corners of the drone landing gear and pinned in place. The restraint cables (two per drone) pass through the restraint rollers. The cables are secured to the after end of the flight deck by quick release hooks and are stretched taut by tensioning devices in the hangar. The handling wheels are installed at the midpoint of the skids, and the skids are jacked clear of the deck. The towing bridles attach to the shafts of the restraint roller assemblies, one forward and one aft. The towing cables pass from the winch in the hangar, through sheaves on the deck, to the towing bridles. The electric winch is provided with two drums, each one serving alternately to tow and snub the drone, depending on whether the drone is being moved away from or toward the hangar. The drums are controlled by levers: one lever clutches the towing drum to the motor drive; the other lever serves to brake the snubbing drum. To tow the drone in the opposite direction, the levers are moved in the opposite direction, and the functions of the two drums are reversed.

    When the drone reaches the launching area, a tie down device with a remotely actuated disconnect mechanism is rigged. The quick release hooks are tripped, and the cables slacken. The towing bridles and restraint roller assemblies are removed, and the restraint cables are looped back toward the hangar. The drone is turned on the handling wheels to the required launching angle on the deck. The skids are lowered to the deck, the tie down cables are tightened, and the handling wheels are removed.

    After the drone has landed on the deck, the launcher - retriever system is re-rigged and the drone is towed back into the hangar.

1. Restraint cables
2. Handling wheel
3. Struts

4. Towing bridles
5. Quick release pins
6. Skid

7. Restraint roller assembly

Figure 1: Restraint Rollers, Towing Bridle, and Handling Wheels Installed



    The drone is equipped with orientation lights for night operations. These lights consist of an amber light forward, bracket mounted to the engine compressor case, two green lights mounted on the right-hand landing gear struts, two red lights mounted on the left-hand struts, and a white light aft, attached to the flotation case assembly mounting shelf.

    When used, the lights are turned on prior to launch and turned off following landing. No in-flight control of the lights is provided. The switch is mounted on a transformer located on the after side of the avionic panel. To turn the lights on bright, move the switch lever fully forward; to turn the lights on dim, move the switch lever fully aft. To turn the lights off, move the switch lever to its center position.



    The weapons are suspended in Mark 8 Mod 4 bomb shackles. When two Mark 44 torpedoes are carried, the bomb shackles are attached, side-by-side, to lugs on the transmission and fuselage support casting. When one Mark 46 torpedo is carried, its shackle is attached to the central lugs. The left-hand release solenoid cable is connected to the shackle release solenoid in a center installation.

    The Mark 44 torpedoes are equipped with Mark 64 suspension bands and Mark 24 Mod 2 air stabilizers. The Mark 46 torpedo is equipped with Mark 78 Mod 0 suspension bands and a Mark 31 Mod 0 air stabilizer. The air stabilizers are of the parachute type. The function of the parachutes is to stabilize and retard the torpedoes along their trajectories from the drone to water entry. As each weapon is dropped, a static line tied to the airframe opens the parachute cover allowing the parachute to open. When the torpedo hits the water, the decelerating forces actuate a release mechanism which uncouples the parachute from the torpedo.

    The suspension bands must be installed so that the center of gravity of the Mark 44 and Mark 46 torpedoes, with air stabilizers installed, is 2.7 ± 0.25 inches forward of the mast centerline.

    The weapon drop envelopes for Mark 44 and Mark 46 torpedoes are shown in the “Performance Data” section.



    The weapon skid is government furnished equipment and is used to transport weapons from the torpedo stowage house, adjoining the hangar, to the drone in the hangar. The weapon skid is a four-wheeled dolly equipped with handles, which have dead man brake grips. (See figure 2-left.) The weapon rests in chocks and is secured with a quick release strap.

    The skid is constrained on the deck by a T-shaped track and follower arrangement, and by a radius arm, which permits the skid to make the 180-degree turn between the torpedo stowage house and the hangar. The track follower is capable of limited vertical travel to permit the skid to be tilted with the front or rear wheels serving as a fulcrum.


The weapon, with suspension bands installed, is loaded on the skid in the torpedo stowage house and is transported to the drone in the hangar (figure 2, detail A). When the torpedo is positioned under the drone, the forward end of the bomb shackle is released from the drone and lowered. The handles of the skid are raised and the shackle engaged with the suspension band lugs (detail B). The tie down strap is released, the skid handles are pushed downward to raise the forward end of the torpedo and shackle, and the shackle reattached to the drone (detail C). The skid is removed and the suspension band release wires attached to the sway braces (detail D).

A section of the track entering the hangar can be moved to guide the weapon skid into the left, center or right-hand weapon position.



The control monitor is installed at the deck control station and is used to start the drone engine and monitor drone and AFC set operation prior to launching. All signals between the control monitor and the drone pass through the engine and AFC set umbilical cables.

The use of the control monitor is covered in “Normal Procedures” section. The function of the controls and indicators is described in the “Description” section. The instrument markings are explained and illustrated, where necessary, in the “Operating Limitations” section.

Prior to launching the drone the umbilical cables are remotely disconnected from the drone by the actuation of a switch on the control monitor panel.



The emergency flotation system (figure 3) is an independent, self-sustaining device, which permits recovery of a drone that has crashed at sea. The system consists mainly of an inflatable flotation bag with a flashing beacon at its top, an air tank to inflate the flotation bag, a salt water activated battery to supply power to the flashing beacon, and a hydrostatic release assembly to activate the system. The flotation bag, air tank, and battery are housed in a styrene container, bracket mounted on the rear of the avionic panel. The container is held to its mounting by a retention harness secured at one end by a locking device on the hydrostatic release assembly. A nylon line (painter assembly) is attached between the drone structure and the flotation bag to prevent the drone from sinking beyond the length of the line.

In the event of a crash at sea, the drone submerges to a predetermined depth. At this depth the hydrostatic release assembly trips the locking device, which frees the retention harness and the styrene container floats free of the drone. When the container is clear of the drone structure, a lanyard on the nylon painter assembly trips a valve which releases the air from the air tank to inflate the flotation bag, preventing the drone from sinking beyond the length of the painter assembly. The flashing beacon, which is above the water surface, guides a retrieval crew to the location of the ditching.


End of Auxiliary Equipment Section


Home Up Description Normal Procedures Emergency Procedures Auxiliary Equipment Operating Limitations Flight Characteristics Systems Operation Crew Duties All Weather Ops Performance Data


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