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A/A47U-3A AND A/A47U-4 TOW TARGET REELING MACHINE-LAUNCHER SYSTEMS
Mk 8 Target Release Ring - 14313_185

Aviation Ordinanceman - Aviation theories and other practices
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weapon training system. It is used to tow aerial targets for gunnery and aircraft missile firing exercises. The system is a semiautomatic tow-reel and target-launching mechanism externally mounted on the aircraft. The A/A47U-3A system consists of an RMK-19A/A47U-3 reeling machine launcher, a PEK-84/A47U-3 reeling machine-launcher control, and the applicable interconnection cable assemblies. The system uses saddle-mounted aerial targets from 7 to 12.5 inches in diameter that weigh up to 225 pounds. Target towlines, which have constant diameters or stepped diameters with combinations of monofilament and/or stranded wire, are used. The system operates with various towline splices, ranging in diameter up to 0.250 inch and with flexible lengths up to 106 inches. Typical towlines consist of 10,000 feet of 0.190-inch diameter 3 by 7 stranded steel cable (5,400-pound tensile strength) or 42,000 feet of 0.097-inch diameter 1 by 7 stranded steel cable (2,060-pound tensile strength). The reeling machine-launcher system has a nominal reeling speed capability of 3,500 feet of towline per minute. Adjusting the power unit blade angle limitations increases the speed to a maximum of 5,000 feet per minute. The operator manually controls the system, and it provides   launcher   up/down,   brake   on/off,   and   reel in/out  functions.  You  can  control  target  reeling  and recovery speeds by manually adjusting the power unit blade angle. Operation of the system is controlled from the   PEK,   which   is   located   in   the   cockpit   of   the launching aircraft. The A/A47U-4 tow target reeling machine-launcher system is identical to the A/A74U-3A  except  for  weight  and  size.  The  lighter weight  and  smaller  size  design  of  the  A/A47U-4  was developed  to  adapt  this  towing  system  to  a  variety  of aircraft. If you want more information on the A/A47U-3A tow  target  reeling  machine-launcher  system,  refer  to Tow Target Reeling Machine-launcher System A/A47U-3A, NAVAIR 28-10A-16. TOW CABLES AND ASSOCIATED EQUIPMENT Steel cables used in target towing are manufactured specifically for that purpose. Three of the several types of cables used are discussed here: the 3/32-inch, 7 by 7 cable;  the  1/8-inch,  7  by  19  cable;  and  the  1/8-inch, 1 by 19 armored cable. The 3/32-inch cable comes in 10,000-foot spools, has a minimum breaking strength of 920 pounds when new, and is 7 by 7 in construction. It consists of seven strands; each strand has seven wires, and is commonly referred to as 7 by 7. This cable weighs 1.5 pounds per 100 feet. The 1/8-inch cable is shipped in either 11,500- to 12,500-foot spools or 7,000- to 7,500-foot spools. It has a  minimum  breaking  strength  of  2,000  pounds  when new. It is 7 by 19 in construction (7 strands, 19 wires per strand) and weighs 2.9 pounds per 100 feet. The 1/8-inch-armored cable is shipped in spools. It has a minimum breaking strength of 2,160 pounds. It is constructed   of  one   strand   of  19  wires,   with   a  flat armoring wire swaged spirally around the strand with a minimum   of   6   turns   per   inch.   The   armored   cable weighs 4 pounds per 100 feet. Cross-sectional views of these three cables are shown in figure 8-4. These cables are not lubricated. The use of grease, oil,  paraffin,  or  other  lubricants  on  the  cable  is  a  fire hazard.  An  explosive  vapor  is  created  in  the  towing aircraft as the cable is reeled out at high speeds. Since the cables are not lubricated, they must be stored in a dry place, or cleaned and coated with corrosion-preventive compound according to instructions. Continual use of a cable reduces its strength. Target towing subjects the cable to severe stress in addition to the  damage  caused  by  gunfire.  You  need  to  inspect cables  frequently.  The  cable  should  be  repaired  or replaced  if  there  are  indications  of  fraying  (broken wires),  birdcaging  (partial  unwinding  of  the  strands along the cable), or snarling (unwinding of the strands 8-4 Figure 8-4.—Cross-sectional view of tow cables.







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