CHAPTER 4 PYROTECHNICS

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1 CHAPTER 4 PYROTECHNICS Pyrotechnics are items that produce their effect by burning, and are consumed in the process. Pyrotechnics, as used in the military, are items that produce a bright light for illumination or colored lights or smoke for signaling and decoying. All Navy pyrotechnic devices contain combustible chemicals. When ignited, these chemicals generate a flame, flash, infrared (IR) radiation, smoke, sound display, or combinations of these effects for many purposes. Some of these effects are visual and audible signaling, area and target illumination, reference-point marking, indication of practice weapon impact or fuze action, tracking, decoying, simulating, and smoke-screen generation. Dye-marking devices are pyrotechnics and screening devices, even though their display is not the product of combustion. They are classed as pyrotechnic or screening devices because their end purposes are quite similar to those of the true pyrotechnic. Dye-marking devices are used to establish reference points on the surface of the water. In some cases, the dye is spread on the surface by explosive means. Pyrotechnics generally function by means of an ignition train, similar to the explosive train of highexplosive ammunition. For further information on pyrotechnics, you should refer to Pyrotechnic, Screening, Marking, and Countermeasure Devices, Naval Sea Systems Command (NAVSEA) SW050-AB-MMA-010/Naval Air Systems Command (NAVAIR) LEARNING OBJECTIVES When you have completed this chapter, you will be able to do the following: 1. Identify the purpose of hand-manipulated signaling devices. 2. Describe the purpose of area and target illuminating devices. 3. Describe the characteristics of aircraft-launched smoke and flame marking devices. 4. Recognize the methods used to launch functional aircraft-launched smoke and flame marking devices. 5. Identify the purpose of decoy devices. 6. Identify the purpose of practice bomb signal cartridges. 7. Recognize the safety precautions to follow when working with pyrotechnics. HAND-MANIPULATED SIGNALING DEVICES Hand-manipulated devices are used for various signaling purposes, such as identification, recognition, warning, and distress. Pyrotechnic Pistols Pyrotechnic pistols Mark (Mk) 1 Modification (Mod) 0 (Figure 4-1) and AN-M8 (Figure 4-2) are breech loaded, double-action, single-shot devices. The barrel is hinged to the frame and held in position by a breech block or latch pin. All are fired by pulling a pistol-type trigger. 4-1

2 Figure 4-1 Pyrotechnic pistol, Mk 1 Mod Figure 4-2 Pyrotechnic pistol, AN-M8. These devices are capable of firing various types of marine signaling devices. Refer to Table 4-1. Table 4-1 Pyrotechnic Pistols and Projectors ITEM Mk 1 Mod 0 Pyrotechnic Pistol AN-M8 Pyrotechnic Pistol Mk 31 Mod 0 Surface Signal Projector Mk 124 Mod 1 Marine Smoke and Illumination DEVICES LAUNCHED Mk 2 Marine Smoke Signal Mk 1 Marine Illumination Signal Mk 1 Marine Illumination Signal Mk 2 Marine Smoke Signal Mk 50 Decoy Flare AN-M37A2 through AN-M45A2 Aircraft Illumination Signal AN-Mk 1 Marine Location Marker M11 Aircraft Illumination Signal Mk 80 Hand-Fired Signal Mk 110 Hand-Fired Signal The Mk 124 Mod 1 signal is intended to be used for either day or night signaling, as appropriate, by personnel on land or sea. The signal is a one-handed operable device, intended for rescue use. Its light weight (237 grams) and small size permit it to be carried in life vests or flight suit pockets and on life rafts. This signal (Figure 4-3) consists of an aluminum case approximately inches long and inches in diameter; each end is provided with a protective cap. The case has three raised beads around its circumference on the flare (night) end. These circumferential beads positively identify the flare end, by the sense of touch, for nighttime use. A label adhered to the outer surface of the case further identifies the smoke (day) and flare (night) ends and provides precise instructions for use. The case contains four subassemblies: smoke candle, smoke igniter, flare candle, and flare igniter. The igniter is one-hand operable and consists of an arming lever that must be extended before functioning and a mechanism that cocks (then releases) the firing pin.

3 For proper functioning of the Mk 124, extend the lever to the armed position and then depress it to cock and release the firing pin. This action allows the striker on the firing pin to hit the primer, which ignites the flare candle (night) or the smoke candle (day) depending on the display desired. The signal emits an orange smoke or red flare for approximately 20 seconds. Mk 79 Mods 0 and 2 Illumination Signal Kit The Mk 79 Mods 0 and 2 signal kit (Figure 4-4) consists of a Mk 31 Mod 0 Surface Signal Projector, a plastic bandoleer that holds seven Mk 80 Mod 0 signals, and an instruction sheet. A 48-inch-long cord is attached to the bandoleer and signal projector. The Mk 79 Mod 2 kit contains Mk 80 Mod 2 signals. The Mk 80 Mod 0 Hand-Fired Signal consists of an aluminum case approximately 2.25 inches long and 0.50 of an inch in diameter. The case contains Figure 4-3 Mk 124 Mod 1 marine smoke and illumination signal. a percussion primer on one end and a steel end cap on the other end. The primer end of the case is threaded for attachment to the Mk 31 Mod 0 projector. The signal contains 3.0 grams of red pyrotechnic flare composition, 1.0 gram of black powder ignition composition, and 250 milligrams of black powder expellant charge. The Mk 80 Mod 2 signal is similar to the Mod 0 design. The Mod 2 design incorporates an expellant charge disc assembly and replaces the black powder ignition charge with 1.0 gram of red lead/silicon ignition mixture. In an emergency or during rescue operations, downed aircrew personnel use the distress signaling device kits. Because it is small and lightweight, personnel can carry it in pockets of flight suits or in life rafts. The projector aims and fires the signals. Each signal contains a single red star. On activation, this star is propelled upward to a height of between 250 and 650 feet. The star burns for a minimum of 4.5 seconds. NOTE This first step is very important because the signal is threaded and screwed into the end of the projector. If you do not cock the projector before screwing in the signal, the firing pin could be forced into the primer of the signal, possibly firing the signal prematurely. To operate the device, cock the projector firing pin by moving the trigger screw to the bottom of the vertical slot, and slip the screw to the right so it catches at the top of the angular slot. After cocking the firing pin, remove a signal from the bandoleer and mate the projector with the signal. While pointing overhead at a slight angle away from the body, rotate the projector clockwise until the signal 4-3

4 is seated. While firmly gripping the projector, fire the signal by slipping the trigger screw to the left, out of the safety slot, and into the firing slot. Figure 4-4 Mk 79 Mod 0 and 2 Illumination Signal Kit. Mk 108 Mod 1 Illumination Signal Kit The Mk 108 Mod 1 Illumination Signal Kit is intended to be used as a signaling device. The kit is small and light in weight so that it can be carried in the pocket of a flight suit or on a raft. The signals in this kit produce a single green star display at a minimum altitude of 250 feet for a minimum time of 4.5 seconds. This kit consists of one Mk 31 Mod 0 Surface Signal Projector, a plastic bandoleer holding seven Mk 110 Mod 1 Hand-Fired Signals, and an instruction sheet. A 48-inch-long cord is attached to the bandoleer and signal projector. The Mk 110 Mod 1 Hand-Fired Signal consists of an aluminum case approximately 2.25 inches long and 1/2 inch in diameter. The case contains a percussion primer on one end and a steel end cap on the other end. The primer end of the case is threaded for attachment to the Mk 31 Mod 0 projector. The signal contains 3.0 grams of green pyrotechnic flare composition, 1.0 gram of red lead/silicon ignition composition, and 250 milligrams of black powder expellant charge. 4-4

5 AREA AND TARGET ILLUMINATING DEVICES The illuminating devices discussed in this chapter are designed to be launched or dropped from aircraft. Aircraft flares are used to illuminate large areas for bombardment, reconnaissance, emergency aircraft landing, or other purposes where a high-intensity light is required. LUU-2B/B Aircraft Parachute Flare The illumination unit (LUU)-2B/B flare is 36 inches long, 4.9 inches in diameter, and weighs about 30 pounds. The flare is supplied only as an all-up-round (AUR), and may or may not be shipped assembled with drogue trays for dispenser launch. Drogue trays are no longer used because the suspension underwing unit (SUU)-44 dispensers are no longer in service. The flare is hand launched or configured for launching from Improved Multiple Ejector Rack (IMER) or Improved Triple Ejector Rack (ITER) aircraft bomb racks or from the SUU-25(series) launchers. Components The LUU-2B/B flare (Figures 4-5 and 4-6) has four major components: Mechanical timer assembly Parachute suspension system Ignition system Case-candle assembly Figure 4-5 LUU-2B/B and LUU-19(series) aircraft parachute flare. The mechanical timer assembly consists of a mechanical timer and related hardware in a Lexan plastic housing. The mechanical timer is a three-gear timer, powered by a torsional mainspring. A phosphorescent plastic decal with calibrated markings from 250 to 11,000 feet of fall is located on the face of the timer cover. A white, plastic dial timer knob is used to set the desired drop distance. Settings of 250, 500, and 1,000 to 11,000 feet can be selected. A safe setting is also provided. 4-5

6 Figure 4-6 LUU-2B/B and LUU-19(series) aircraft parachute flare cutaway. An 18-foot diameter cruciform-shaped canopy parachute suspension system is used for good stability of the LUU-2B/B flare. The riser cables connect the parachute to a bulkhead. The bulkhead separates the parachute compartment from the remainder of the flare assembly. One cable is attached to an explosive bolt for parachute dump at candle burnout. In the ignition system, a lanyard is attached to one of the parachute riser cables. This lanyard is threaded through the bulkhead and past the candle in an internal raceway along the side of the aluminum case. The raceway leads to the ignition assembly in the ignition housing near the candle's face. The lanyard is attached to a triggering mechanism, which consists of the out-of-line igniter (OLI- 2/A). Upon ignition, the firing pin initiates the pyrotechnic firing train. The case-candle assembly contains a tamp-cast illuminating candle that consists of a composition of magnesium, sodium nitrate, and a polymer binder. The flare is designed so that the outer aluminum case is partially consumed during candle burning. Operation A lanyard is attached to the timer knob on the flare timer during flare uploading procedures. The lanyard is also connected to the bomb rack or green arming cap, depending on the launch configuration. At launch, the lanyard pulls the timer knob out of the timer (requiring approximately 30 pounds of force), starting the clock mechanism. After the preset time (drop distance) ends, the three locking pawls in the timer assembly release, retracting and releasing the timer assembly. A spring, located between the timer assembly and the packaged parachute, expels the timer assembly, which, in turn, initiates removal of the parachute from the flare case. When the cord breaks, it separates the timer assembly from the parachute. As the parachute system deploys and its main cables are pulled taut, the ignition lanyard is pulled to activate the ignition system. The ignition lanyard must exert a pull force in excess of 90 pounds to pull the slider assembly in line. This, in turn, releases the firing pin against the primer. The primer ignites a propellant wafer that produces sufficient heat for candle ignition. Pressure buildup during candle ignition blows off the igniter housing, and the candlepower reaches a nominal value. Just before candle burnout, the explosive bolt functions to release one of the suspension cables, causing the parachute to dump. The LUU-2B/B candle is not ejected from the case on the LUU-2B/B flare. Only the parachute is removed from the case, which is accomplished by a mechanical timer and spring. Therefore, if the timer knob should be accidentally pulled during handling when the timer is not on the safe setting, the timer and release mechanisms can be forcibly hand held onto the flare housing to prevent ejection of 4-6

7 the timer and release mechanisms. When the timer completes its cycle, the timer mechanism can be taped on the flare housing and marked for disposal. If the timer is ejected from the flare and a portion of the parachute comes out of the housing, the parachute can be stuffed back into the housing, taped, and marked for disposal. If the parachute should accidentally deploy on the flight deck/line, the opening shock from deck winds or jet blast is not sufficient to ignite the candle. LUU-19(Series) Aircraft Parachute Flare The LUU-19(series) aircraft parachute flare (Figures 4-5 and 4-6) consists of four major subassemblies: the timer assembly, parachute suspension system, ignition system, and candle assembly. The timer has a decal with calibrated markings from 250, 500, and 1,000 to 11,000 feet of fall and a safe position. The LUU-19(series) is IR spectrum variant of the LUU-2B/B paraflare. The LUU-19(series) has the same physical dimensions as LUU-2B/B, but weighs 6 pounds more and provides IR illumination of the target area for night vision goggle- (NVG-) capable aircraft. The flare is compatible with all standard flare launching systems and can be deployed from aircraft wing-mounted racks and the SUU-25(series) launchers. It can also be hand launched from an aircraft. The LUU-19(series) has been developed to illuminate in the near IR region of the spectrum. This illumination dramatically enhances the capability of the military's night vision devices used for covert night operations while eliminating the need to use other flares that radiate bright illumination. AIRCRAFT-LAUNCHED SMOKE AND FLAME MARKING DEVICES Smoke and flame marking devices are pyrotechnic devices dropped on the ground or on the water's surface to emit smoke and/or flame. Reference points established by these devices serve a variety of purposes. They can be used to determine wind direction and approximate velocity, mark the location on the surface for emergency night landings, establish an initial contact point for continued search for a submarine, or locate target areas in antisubmarine warfare. Mk 25 Mods 3 and 4 Marine Location Marker The Mk 25 Mods 3 and 4 (Figure 4-7) Marine Location Markers (MLMs) are launched from aircraft or surface craft. They are launched from aircraft to provide day or night reference points for marking the course of enemy submarines in antisubmarine warfare operations. They are suitable for any type of Figure 4-7 Mk 25 Marine Location Marker. 4-7

8 sea-surface reference-point marking that calls for both smoke and flame for a period of 13.5 to 18.5 minutes. Mods 3 and 4 function identically. The differences include the configuration of the base assembly arming procedure, the addition of a protective cap on the Mod 4, and the pyrotechnic scuttling feature of the Mod 4. Physical Description The Mk 25 marker consists of a cylindrical outer tube about 18.5 inches long and 3 inches in diameter. A valve assembly is fitted into the projecting chimney at the marker's nose end. The smoke and flame are emitted from this opening. At the opposite end is a heavier aluminum base assembly to which the outer tube is crimped. The heavy base end causes the marker to float in the water with the chimney out of the water and the base in the water. Within the base assembly is a Mk 72 Mod 0 seawater-activated battery. The Mk 25 Mod 3 battery is shielded from water contact by two plugs fitted into 1/2-inch holes on two opposite sides of the base assembly. A rigid cover (arming plate), held in place by a retainer ring, is recessed into the base end. An arrow in the center of the arming plate indicates its safe or armed position. The words SAFE and ARMED are stamped into the base rim. Also, a machined notch in the rim at the armed position helps during night use. When the arming plate is in the safe position, it physically blocks the base plugs internally to prevent them from being accidentally pushed in. When in the armed position, the arming plate no longer blocks the base plugs, allowing them to be pushed in at the appropriate time. A black rubber G-ring circles the base assembly approximately 1/4 inch from the crimp, which holds the outer case. The Mk 25 Mod 4 has an arming cap that is housed at the base under the protective cap. The arming cap is rotated and removed to arm for deployment. If the marker is not deployed, the arming cap can be replaced and rotated to safe and the protective cap reinstalled. Functional Description To activate the seawater battery, the base plugs on the Mod 3 are pushed in or the arming cap is rotated and removed on the Mod 4 before the marker is actually launched. An electric squib ignites the marker, and the seawater-activated battery supplies power. When the marker enters the water, seawater enters the battery cavity and serves as an electrolyte, causing the battery to produce a current that activates the squib. The squib ignites the starter mix, which, in turn, ignites the red phosphorous pyrotechnic composition. Gas buildup forces the valve assembly from the chimney in the nose, and yellow flame and white smoke are emitted. Burning time averages 13.5 to 18.5 minutes. Although the Mod 3 marker is normally used in seawater, it can be used in inland bodies of fresh water by using table salt and following the procedures outlined in Pyrotechnic, Screening, Marking, and Countermeasure Devices, NAVSEA SW050-AB-MMA-010/NAVAIR Launching Methods Currently, there are two methods of launching the Mk 25 marker by hand or by sonobuoy launcher. To launch the Mod 3 by hand, rotate the base arming plate clockwise to the armed position. Next, push the base plugs into the battery cavity, located in the marker base, and throw the marker into the water. It functions as previously discussed. To launch the Mod 4 by hand, remove the protective cap, rotate and remove the arming cap, and throw the marker into the water. 4-8

9 If the base plugs (one or both) of a Mod 3 marker are disturbed so that the watertight integrity of the battery cavity is compromised and the marker is not launched immediately, install the Mk 34 Mod 0 marine marker adapter kit. Use the Mk 34 Mod 0 adapter kit when the marker is launched from a sonobuoy launcher. The adapter kit fits over the base end of the marker, and, when properly installed, seals the battery cavity. Install the adapter kit by rotating the marker base arming plate to the armed position and pushing the base plugs into the battery cavity. Remove the black G-ring, and install the adaptor kit around the marker base so that the seal plugs on the leaf-spring ends cover the holes into the battery cavity. Install the U-pin to hold the adapter in place. To hand launch a marker with a Mk 34 adapter kit installed, remove the U-pin and the adapter and throw the marker into the water. Before launching the Mk 25 marker from a sonobuoy launcher, install a Mk 34 adapter kit (Figure 4-8) on the Mod 3 marker. The adapter kit provides a safe environment for the marker until the last possible moment before launch. Because of the physical difference in size between the Mk 25 marker and the sonobuoy launch tubes, a sonobuoy launch container (SLC) and spacer assembly (Figure 4-8) is used to launch the Mk 25 marker from a sonobuoy launcher. Figure 4-8 Spacer assembly and sonobuoy launch container. 4-9

10 Place the Mk 25 Mod 3 marker, with the Mk 34 adapter installed, in the cavity of the split foam spacer assembly section with the U-pin in the up position. Remove the U-pin and install the other half of the split foam spacer assembly enclosing the marker. Remove the MK 25 Mod 4 protective cover and place the marker into the cavity half. The arming cap is fully depressed and released to expose the word ARM, and the other foam spacer split section is placed over marker. The foam spacer assembly containing the marker is then installed into the SLC against the obturator. Foam pads are installed, and the end cap is locked into slots in the SLC, retaining the assembly inside the SLC. A JAU-22 cartridge is installed in the SLC, and the loaded SLC is installed in the sonobuoy launcher aboard the aircraft. To launch the Mk 25 marker, the JAU-22 cartridge is initiated through the aircraft circuitry. It develops sufficient gas pressure inside the SLC to force off the SLC end cap and expel the foam spacer assembly containing the Mk 25 marker. Once out of the SLC, the split foam spacer assembly is separated by the airstream, freeing the marker. The airstream then separates the Mk 34 adapter kit from the Mod 3 marker, allowing them to fall to the water as separate units. Upon entry into the water, the marker emits smoke and flame as previously discussed. Mk 58 Mod 1 Marine Location Marker The Mk 58 Mod 1 MLM (Figure 4-9) is designed for day or night use in any condition calling for long-burning smoke and flame reference-point marking on the ocean's surface. In addition to being used for antisubmarine warfare, it is used for search and rescue operations, manoverboard markings, and as a target for practice bombing at sea. The marker produces a yellow flame and white smoke for a minimum of 40 minutes and a maximum of 60 minutes. It is visible for at least 3 miles under normal operating conditions. Physical Description The Mk 58 Mod 1 MLM consists of a cylindrical tin can approximately inches long and 5 inches in diameter. The can contains two pyrotechnic candles of a red phosphorus composition. The ignition end of the marker has three holes two for smoke and flame emission and one for water to enter the Mk 72 Mod 1 seawater-activated battery. Adhesive foil disks Figure 4-9 Mk 58 Mod 1 Marine Location Marker. 4-10

11 hermetically seal the two emission holes. A reinforced adhesive foil strip with a rectangular pull ring hermetically seals the battery cavity hole. The adhesive foil seals are protected during handling and shipping by a replaceable polyethylene protective cover. Launching Methods The Mk 58 Mod 1 marker may be hand launched, externally launched from suitable aircraft bomb racks by using breakaway suspension bands, or launched from sonobuoy launchers by using an SLC and the appropriate foam spacer. No matter how the marker is launched, the protective cover, the pull ring, and reinforced adhesive foil strip over the battery s cavity are removed. When the marker is launched from suitable aircraft bomb rack, breakaway suspension bands (BASBs) are used for external aircraft carriage. The BASBs and marker are secured to the bomb rack and an arming wire is attached to the pull ring. Attachment of a lanyard or the use of an arming wire between the pull ring of the marker and the launching mechanism is to ensure removal of the tape sealing the battery. When the marker is released from the bomb rack, the arming wire retains the pull ring and removes the foil strip covering the battery's cavity. When submerged, the Mk 72 Mod 1 battery is activated by seawater. Current from the battery initiates a Mk 13 electric squib, which ignites the starter composition of the first pyrotechnic candle. The composition ignites the starter pellet, which, in turn, ignites the first candle. When the first candle is nearly burned out, its heat ignites the transfer time fuze, which carries ignition to the second candle starter composition and initiates the second pyrotechnic candle. DECOYING DEVICES Decoy flares are dispensed from launching mechanisms on aircraft. They are fired during evasion tactics when the aircraft is threatened by enemy heat-seeking missiles. Infrared Decoys All IR decoys generate heat and infrared energy, which is used to distract an infrared heat-seeking missile away from the aircraft. Currently there are two different forms of IR decoys. One is composed of a pyrotechnic composition that is ignited and burns while falling away from the aircraft. The other is composed of a pyrophoric metal, shaped like thin wafers, that reacts with oxygen in the air once it is dispensed. Basically, the material rusts so quickly that it gives off a heat signature, which is in the sensing spectrum of the missile s heat-seeking sensor. MJU-27A/B and MJU-49/B Decoy Devices The MJU-27A/B and MJU-49/B Decoy Devices are launched from the AN/ALE-39 Countermeasure Dispensing System (CMDS), and AN/ALE-47 CMDS. A nonconventional pyrophoric metal payload is utilized in each device to provide a tactical advantage over conventional decoys in some situations. The MJU-27A/B and MJU-49/B Decoy Devices consist of a cylindrical aluminum case approximately 5.8 inches long and 1.4 inches in diameter (Figure 4-10). The base end of the flare is flanged to a maximum diameter of inches to fit the counterbore in the chamber of the dispenser blocks. The end of the flare case opposite the flanged base is closed with an aluminum end cap with an O-ring seal. These devices consist of three major elements: the payload, piston, and end cap. The payload consists of pyrophoric metal. The piston is located between the payload and the cartridge retainer. 4-11

12 The end cap has an O-ring seal for protection of the pyrophoric metal payload. The end cap is crimped to the cartridge case. This device requires the CCU-136A/A Impulse Cartridge for functioning. Figure 4-10 MJU-27 and MJU-49 decoy devices. MJU-32/B, MJU-32A/B, MJU-38/B and MJU-38A/B Decoy Flares These decoy flares are conventional pyrotechnic magnesium/teflon/viton (MTV) flares that are utilized to decoy IR heat-seeking missiles. These flares are launched from the AN/ALE-39 CMDS and AN/ALE-47 CMDS. The MJU-32A/B and MJU-38A/B are form, fit, and function replacements for the MJU-32/B and MJU- 38/B. Improvements were made to ignition reliability. These decoy flares consist of a cylindrical aluminum case approximately 5.8 inches long and 1.4 inches in diameter (Figure 4-11). The base end of the flare case is flanged to a maximum diameter of inches to fit the counterbore in the chamber of the dispenser block. The end of the flare case opposite the flanged base is closed with an injected molded polycarbonate end cap attached by a 360-degree crimp. The MJU-32A/B and MJU-38A/B have a plastic cartridge retainer threaded and sealed into the base of the flare case. These decoy flares consist of two major elements: the pyrotechnic composition (or flare grain) and the igniter assembly. In the MJU-32/B and MJU-38/B, the complete length of the grain is wrapped with adhesive-backed aluminum foil that extends over part of the igniter. In the MJU-32A/B and MJU-38A/B, the adhesive-backed aluminum foil is 1 inch wide and covers the gap between the grain and igniter assembly. The igniter assembly contains a plastic body, two ignition pellets, and bore-sensing sliders. A silicone rubber pad is located between the end of the flare grain and end cap to provide for variations in longitudinal dimensions of the parts with time. It also provides protection for the internal parts by damping vibration and shock forces. This device requires the CCU-136A/A impulse cartridge for functioning. 4-12

13 Figure 4-11 MJU-32 and MJU-38 decoy flare. MJU-55A/B and MJU-55/B Decoy Flare-Devices The MJU-55A/B and MJU-55/B Decoy Flare-Devices are launched from the AN/ALE-39 CMDS and AN/ALE-47 CMDS. The MJU-55A/B and MJU-55/B flares consist of a cylindrical aluminum case approximately 5.8 inches long and 1.4 inches in diameter (Figure 4-12). The base end of the flare case is flanged to a maximum diameter of inches to fit the counterbore in the chamber of the dispenser block. The MJU-55A/B has a black plastic squib seal installed in the impulse cartridge cavity. The end of the flare case opposite the flanged base is crimped 360 degrees around the aluminum end cap, which is sealed with an O-ring. These flares consist of two payloads: a pyrotechnic MTV grain with an igniter and a pyrophoric metal payload. The igniter assembly contains a plastic body, two ignition pellets, and two bore-sensing sliders. The two payloads are separated by a rubber separator disk. 4-13

14 MJU-57A/B and MJU-57/B Decoy Flares Figure 4-12 MJU-55 Decoy Flare-Device. The MJU-57A/B and MJU-57/B Decoy Flares are launched from the AN/ALE-39 CMDS and AN/ALE- 47 CMDS. The MJU-57A/B is a form, fit, and function direct replacement for the MJU-57/B, incorporating design features to improve safety, producibility, reliability, and unit cost. The MJU-57A/B and MJU-57/B Decoy Flares consist of a cylindrical aluminum case approximately 5.8 inches long and 1.4 inches in diameter (Figure 4-13). The base end of the case is flanged to a maximum diameter of inches to fit the counterbore in the chamber of the dispenser block. For the MJU-57/B, the end of the flare case opposite the flanged base is crimped 360 degrees around the payload stainless-steel end cap, which is inserted with a tungsten slug. For the MJU-57A/B, the end of the flare case opposite the flanged base is crimped 360 degrees around the plastic payload end cap. It also has a plastic cartridge retainer threaded and sealed into the base of the flare case. The MJU-57/B Decoy Flare consists of two major elements: the rocket motor assembly and the igniter assembly. The pyrotechnic grain is housed in a stainless-steel tube/end cap and molded plastic nozzle assembly. A tungsten slug, which is staked into the end cap, provides a forward weight in the rocket motor assembly, which acts to stabilize the payload in flight. Spring-loaded fins, which deploy once the payload is ejected from the case, also act to stabilize the payload in flight. The igniter assembly contains a plastic body, two ignition pellets, and two bore-sensing sliders. The MJU-57A/B Decoy Flare consists of two major elements: the rocket motor assembly and the igniter assembly. The pyrotechnic grain is housed in a plastic nozzle/body assembly. The forward end of the rocket motor assembly contains a tungsten ballast to help with aerodynamic stability, while the other end contains a nozzle for the unit s thrust. Wrapped around the body is a one-piece spring steel fin. The igniter assembly is attached to the nozzle end of the body. The igniter assembly contains a plastic body and two bore-sensing sliders with ignition pellets. 4-14

15 Figure 4-13 MJU-57 Decoy Flares. When properly installed in a chamber of the applicable dispenser, the case fits snugly around the firing end of a corresponding CCU-136A/A Impulse Cartridge. When the impulse cartridge is fired, the gas pressure shears out a thin disk in the case, which allows the gas to exert a pushing force against the igniter/rocket motor assembly. At this time, hot particles from the impulse cartridge ignite the ignition pellets. The pushing force on the igniter/rocket motor assembly causes the end cap to open the case crimp, and the igniter/rocket motor assembly ejects from the case. When the igniter clears the case, the bore-sensing sliders move, allowing the flame from the ignition pellets to transfer to the grain. The fins, which act to stabilize the ejected payload, fully deploy when the igniter/rocket motor assembly clears the aluminum case (Figure 4-14). 4-15

16 SM-875A/ALE SM- 875B/ALE Flare Simulator The SM-875A/ALE Flare Simulator is launched from the AN/ALE-39 CMDS and AN/ALE- 47 CMDS for training and simulation purposes. The SM-875A/ALE Flare Simulator (Figure 4-15) consists of a cylindrical plastic case approximately 5.8 inches long and 1.4 inches in diameter. The base end of the flare is flanged to a maximum diameter of inches to fit the counterbore in the chamber of the dispenser block. The end of the flare case opposite the flanged base is closed with an injection-molded plastic end cap pinned in place with two spring pins and sealed with an O-ring. Figure 4-14 MJU-57/B Decoy Flare functional sequence. Figure 4-15 SM-875A/ALE Flare Simulator. The SM-875B/ALE Flare Simulator (Figure 4-16) provides a low-cost training round that can be used to familiarize pilots and ordnance technicians with the use and handling of decoy flares. It was developed as a visually enhanced replacement for the SM-875A/ALE Flare Simulator. The SM-875B/ALE Flare Simulator is identical in size to the standard MJU-32 and MJU-38 series of flares and uses standard CCU-136A/A Impulse Cartridges. This size allows it to be used with the AN/ALE-39 CMDS or AN/ALE-47 CMDS and their standard-length blocks. 4-16

17 Figure 4-16 SM-875B/ALE Flare Simulator. MJU-50/B Infrared Countermeasure Flare The MJU-50/B IR Countermeasure Flare is launched from a MJU-33/A Multiple Flare Magazine, which is installed on a D-49/ALE-47 CMDS to decoy IR heat-seeking missiles. The MJU-50/B IR Countermeasure Flare (Figure 4-17) consists of a 1- by 1- by 8-inch aluminum case with an aluminum impulse cartridge cup glued into the base of the flare case. This cup has an O-ring that provides a seal when the impulse cartridge is installed. A length of thread is stored in this cup and held in place with a plastic plug. The opposite end is closed with a crimped aluminum disk and sealed with epoxy. Figure 4-17 MJU-50 IR countermeasure Flare assembly. 4-17

18 The MJU-50/B IR Countermeasure Flare consists of a plastic piston and a payload of pyrophoric metal. The piston is located between the payload and the cartridge retainer. The MJU-50/B requires the BBU-35/B or CCU-145/A Impulse Cartridge for functioning. MJU-61A/B and MJU-61/B Decoy Flares The MJU-61/AB and MJU-61/B Decoy Flares are launched from an MJU-33/A Multiple Flare Magazine, which is installed on a D-49/ALE-47 CMDS to decoy IR heat-seeking missiles. These decoy flares (Figure 4-18) consist of a 1- by 1- by 8-inch aluminum case, with a cavity at the base end for the impulse cartridge and an O-ring-sealed end cap crimped in place on the other end. Figure 4-18 MJU-61 Decoy flare. The internal payload of these flares consists of a pyrotechnic flare grain with an igniter assembly attached. The MJU-61A/B igniter assembly has an O-ring, and the MJU-61/B igniter assembly has a polyethylene plastic piston. A silicone foam rubber pad is between the flare grain and end cap. The function of these decoy flares is initiated when voltage is applied across the contacts of the impulse cartridge in response to cockpit command. Hot gases from the impulse cartridge shear the thin section in the base end of the flare case and enter the case. The hot gases then ignite the ignition pellets in the igniter assembly and also pressurize against the payload, causing the pyrotechnic payload to move. The moving payload causes the end cap to separate from the case. As the payload assembly moves along the length of the flare case, two bore-sensing sliders contained in the igniter inhibit ignition of the grain. As the payload assembly exits the case, force from the springs located in the igniters move the sliders. Flame from the burning ignition pellets can now pass through openings and ignite the flare grain. The burning flare grain produces IR energy, which is attractive to advanced IR-seeking missiles. MJU-64/B and MJU-66/B Infrared Countermeasure Decoys The MJU-64/B and MJU-66/B Infrared Countermeasure Decoys are launched from an MJU-33/A Flare Magazine, which is installed on a D-49/ALE-47 CMDS to decoy IR heat-seeking missiles. These decoys (Figure 4-19) consist of a 1- by 1- by 8-inch aluminum case. The base end of the case has a receptacle with an O-ring for the impulse cartridge. The opposite end is closed with a plastic end cap sealed with an O-ring. These decoys consist of a plastic piston and a payload of pyrophoric metal. The pyrophoric metal payloads emit IR energy at slightly different temperatures. The piston is located between the payload and the cartridge retainer. These decoys require the BBU-35/B or CCU-145/A Impulse Cartridge for functioning. For use, an impulse cartridge is inserted into the receptacle in the base of the flare. When the impulse cartridge in the decoy is initiated by the firing pulse, the impulse cartridge receptacle cup s frangible membrane ruptures. Pressure inside the canister increases and pushes on the piston, breaking the end cap seal and deploying the pyrophoric metal payload into the airstream. The pyrophoric metal reacts with the air to emit IR energy. 4-18

19 Figure 4-19 MJU-64 Infrared Countermeasure Decoy. MJU-68/B and MJU-69/B Infrared Countermeasure Flares The MJU-68/B and MJU-69/B Infrared Countermeasure Flares are launched from the AN/ALE-70 CMDS used aboard the Joint Strike Fighter (JSF) F-35 Lightning II aircraft. The MJU-68/B and MJU-69/B Infrared Countermeasure Flares consist of a square aluminum case approximately 1.5 by 1.5 by 10.5 inches long (Figures 4-20 and 4-21). The base end of the case is flanged to approximately 1.65 by 1.65 inches. Figure 4-20 MJU-68/B Infrared Countermeasure Flares. For both flares, the end of the flare case opposite the flanged base is closed with an aluminum end cap staked in place and sealed with room temperature vulcanization (RTV) silicone. Both of these flares consist of two major elements: the flare assembly and the igniter assembly. The pyrotechnic grain is housed in a graphite fabric/phenolic resin housing/body closed with a copper tungsten nose assembly. The nose assembly provides forward weight in the flare assembly, which acts to stabilize the flare in flight. The aft end of the flare assembly has an integral nozzle. An igniter assembly is attached to the nozzle end of the flare assembly. The igniter assembly contains a plastic body, an ignition pellet, and bore-sensing sliders. 4-19

20 Figure 4-21 MJU-69/B Infrared Countermeasure Flares. When properly installed in a chamber of the applicable dispenser, the case fits snugly around the firing end of a corresponding impulse cartridge; a CCU-145/A for the MJU-68/B and a CCU-168/A for the MJU-69/B. When the impulse cartridge is fired, gas pressure shears out a thin disk in the case, allowing the gas to exert a pushing force against the flare assembly. At this time, hot particles from the impulse cartridge ignite the ignition pellet in the igniter assembly. The pushing force on the flare assembly causes the end cap to open the case crimp, and the flare assembly ejects from the case. When the igniter assembly clears the case, the bore-sensing sliders move, allowing the flame from the ignition pellet to transfer to the grain. As pressure from the burning flare grain exiting the nozzle pushes the igniter assembly off the flare assembly, the gases produce thrust, propelling the flare through the air. The weighted nose assembly and fins integral to the graphite fabric/phenolic resin housing/body stabilize the flare in flight. Radio Frequency Expendables Active and Passive The active expendables generate radio frequency (RF) energy on their own, instead of reflecting the radar energy back toward the radar. The passive expendables are filled with chaff. Chaff is aluminum-coated glass fibers that are dispensed by aircraft to mask or screen other aircraft or to cause tracking radar to break lock. The materials are generally cut into small pieces for which the size is dependent upon the radar interrogation frequency (approximately one-half the wavelength of the victim radar frequency). Being one-half a wavelength long, chaff acts as a resonant dipole and reflects much of the energy back to the radar. RT-1489/ALE This item is commonly referred to as Generic Expendable (GEN-X) (Figure 4-22). A GEN-X is a microwave transmitter/receiver utilizing state-of-the-art microwave-integrated circuits. It is dispensed by the AN/ALE-39 CMDS and AN/ALE-47 CMDS. The security classification of the decoy is the result of resident programming within the electronic modules of the decoy. Declassification may be accomplished by removing the battery and crushing, mutilation, or burning of the modules. The decoy should be handled in accordance with instructions for Class C explosives. 4-20

21 Figure 4-22 RT-1489/ALE (GEN-X) active payload. RT-1646/ALE Series This item is an active towed decoy developed for use with the AN/ALE-50(V) CMDS (Figure 4-23). The RT-1646/ALE Series was designed to protect a variety of aircraft, including the Navy F/A-18E/F. The decoy comprises a receiver, transmitter antennas (fore and aft), a power supply, traveling wave tube, integrated solid state module, and a microcontroller module. It is enclosed in a canister that comprises the cutter assembly and towline assembly. The RT-1646C/ALE and RT-1646E/ALE function similarly to the RT-1646A/ALE Series decoy and are commonly referred to as the RT-1646 series decoy. Figure 4-23 AN/ALE-50(V) CMDS dispenser with decoy target. 4-21

22 RR-129/AL The chaff in the RR-129 (Figure 4-24) is cut into three lengths, resonant at 2.85, 5.062, and gigahertz (GHz). This item is dispensed by the AN/ALE-39 CMDS and AN/ALE-47 CMDS. RR-129A/AL Figure 4-24 RR-129/AL and RR-129A/AL chaff. The chaff in the RR-129A/AL (Figure 4-24) is cut into three lengths, resonant at 2.85, 5.062, and GHz. This unit has the improved case and end cap for reduced end cap loss during carrier catapult-assisted takeoff and arrested landings. This item is dispensed by the AN/ALE-39 CMDS and AN/ALE-47 CMDS. RR-144/AL The chaff in the RR-144/AL (Figure 4-25) is cut into a single length, resonant at GHz. This item is dispensed by the AN/ALE-39 CMDS and AN/ALE-47 CMDS and is generally used for training. RR-144A/AL The chaff in the RR-144A/AL (Figure 4-25) is cut into three lengths, resonant at 7.00, 9.32, and GHz. This unit has the improved case and end cap for reduced end cap loss during carrier assisted launching and recovery. The frequencies do not interfere with Federal Aviation Administration (FAA) radar. This item is dispensed by the AN/ALE-39 CMDS and AN/ALE-47 CMDS and is used for training. 4-22

23 Figure 4-25 RR-144/AL and RR-144A/AL chaff. PRACTICE BOMB SIGNAL CARTRIDGES Practice bomb signal cartridges are used for day and night operations and as a visual indication of bomb impact and fuze function. Three types of signal cartridges are discussed in the following paragraphs. Mk 4 Signal Cartridge The Mk 4 practice bomb signal cartridge (Figure 4-26) consists of an aluminum case. The rim end has a percussion primer, and the opposite end is sealed with an aluminum disk. The signal cartridge contains an expelling charge (smokeless powder) initiated by the primer and red phosphorus. Upon impact, the cartridge is driven forward against the firing pin, initiating the primer at the base of the cartridge. Figure 4-26 Mk 4 signal cartridge. This action fires the 3 grams of expelling charge and propels it from the open end of the practice bomb. The red phosphorus is a toxic powder that produces a bright flash (for night use) and large volumes of white smoke (for day use) when ignited. The signal cartridge will detonate upon impact, releasing volumes of smoke. Drops of 18 inches or more can cause the signal to function. The smoke is produced by the combination of red phosphorus and heat exceeding 2,500 degrees Fahrenheit ( F). The smoke can cause a choking sensation and irritation of the eyes. 4-23

24 CXU-3A/B Signal Cartridge The CXU-3A/B is a good-visibility, daytime use, fire-free signal cartridge designed for use with practice bombs (Figure 4-27). Figure 4-27 CXU-3A/B signal cartridge. The CXU-3A/B is an aluminum cylinder 6.05 inches long with a diameter of inches. The cylinder surrounds a glass ampule that contains approximately 1.0 ounce of titanium tetrachloride, a mildly toxic liquid that produces large volumes of white smoke when exposed to air or moisture. The signal cartridge weighs 2.50 ounces. Upon impact, the cartridge is driven forward against the firing pin, initiating the primer in the base of the cartridge. This action fires 3 grams of expelling charge, which, in turn, shatters the ampule and propels it from the open end of the practice bomb. The resulting cloud of dense white smoke clearly marks the impact point of the practice bomb on the bombing range. CXU-4A/B Signal Cartridge The CXU-4A/B signal cartridge (Figure 4-28) is a fire-free signal employed to provide visual indication of bomb impact point and fuze function. The signal cartridge contains titanium tetrachloride, a mildly toxic liquid that produces large volumes of white smoke when exposed to air or moisture. The signal cartridge is 2.85 inches long with a 2.10-inch diameter and weighs 6 ounces. The signal cartridge consists of 52 cubic centimeters of titanium tetrachloride inside four glass vials, which are encapsulated within a plastic container. Two signals are used in the side wells of practice bomb BDU-45/B Figure 4-28 CXU-4A/B signal cartridge. Signal cartridge function is dependent upon detonation of an associated electric fuze in practice bomb BDU-45/B. Detonation of the fuze shatters the signal cartridge container and disperses titanium tetrachloride, which combines with moisture in the air to form a white cloud.

25 HANDLING AND SAFETY PRECAUTIONS Pyrotechnic ammunition is one of the most widely used types of ammunition in naval aviation. Pyrotechnics of one type or another are carried in almost every Navy aircraft, including unarmed transport and training aircraft. All pyrotechnic and screening devices, while designed and tested to be safe under normal conditions, are subject to accidental ignition. NOTE You should be constantly aware that pyrotechnics contain chemical components that are intended to burn with intense heat, and you should act accordingly. Pyrotechnic and screening devices are normally equipped with some type of safety pin, lock, or tape that is designed to prevent accidental activation of the initiation mechanism. DO NOT tamper with such equipment. DO NOT strike, bend, or otherwise remove the safety equipment until just before the device is launched. Any devices that show signs of damage to the safety features are considered unserviceable; carefully put them to one side and promptly dispose of them according to current directives. If a pyrotechnic device should accidentally ignite, it will result in a fire hazard. In a confined area, the gases generated by this combustion could present a serious toxic hazard. Signaling charges that contain propellant charges, designed to propel the pyrotechnic candle into the air, create an extremely dangerous missile hazard. Pyrotechnic compositions characteristically contain their own oxidants; therefore, they do not depend on atmospheric oxygen for combustion. For this reason, exclusion of air, by whatever means, from a pyrotechnic fire is usually ineffective. Many pyrotechnic mixtures, particularly illuminating flare compositions, burn with intense heat (up to 4,500 F). Normally, extinguishers are not useful in this kind of fire. Carbon dioxide extinguishers, in addition to being ineffective, are potential sources of danger because they tend to produce oxygen, which supports the combustion. Foam-type extinguishers are equally ineffective because they work on the exclusion-of-air principle. NOTE Water, in flooding quantities and at low pressure, should be used to cool the surrounding area and to prevent the spread of the fire. Properly controlled and directed, water is the best fire-extinguishing agent for aircraft parachute flares burning in the open. Pyrotechnic hazards are frequently increased by such factors as age, improper storage conditions, rough handling, moisture penetration, excessive temperatures, damage to shipping containers, and other mishaps that cause the devices to become unserviceable. In most cases, immediate danger does not exist. Unserviceable pyrotechnic and screening devices on ships at sea are put to one side for normal return to an appropriate shore station for disposition according to the instructions and regulations contained in NAVSEA OP 5, Volume 1. Conditions may develop that demand emergency disposal of potentially hazardous devices. In such cases, disposition is the responsibility of the commanding officer. Under NO circumstances, other 4-25

26 than an extreme emergency, should ammunition, explosives, or other related hazardous materials be dumped at sea by a Navy vessel, aircraft, or activity without prior approval of the Chief of Naval Operations (CNO). If, in the commanding officer's best judgment, immediate disposition is necessary to protect lives and property, the commanding officer should order such disposition by the most appropriate means available. In all cases, the commanding officer must notify Naval Sea Systems Command, at the earliest practical time, of the facts and circumstances. 4-26

27 End of Chapter 4 Pyrotechnics Review Questions 4-1. For which of the following signaling purposes is a hand-manipulated signaling device NOT used? A. Identification B. Countermeasure C. Warning D. Distress 4-2. Which of the following features do pyrotechnic pistols NOT include? A. Breech-loaded B. Single-shot C. Double-action D. Double-barreled 4-3. A Mk 124 Mod 1 marine smoke and illumination signal emits what color smoke for day use? A. Blue B. Green C. Orange D. Red 4-4. A Mk 124 Mod 1 marine smoke and illumination signal emits what color flame for night use? A. Blue B. Green C. Orange D. Red 4-5. The day or night end of a Mk 124 Mod 1 signal is marked in which of the following ways? A. The day end is painted orange B. The night end is painted red C. The case has three raised beads around its circumference on the flare (night) end, and a label adhered to outer surface of the case identifies the smoke (day) and flare (night) end D. The protective plastic cap on the day end is molded, and there are prominent protrusions across the face 4-6. A Mk 79 Mod 0 Illumination Signal Kit consists of what total number of Mk 80 Mod 0 signals? A. Five B. Six C. Seven D. Eight 4-27