TM 1-1520-240-10 6-6-24            CAUTION Excessive    tightening    of    the    tiedown straps attached to the outboard row of tie- down fittings will limit the effectiveness of the isolated floor. 6-6-52.  Vehicle Tiedown. Because of the numerous points of attachment available, vehicles are the items of cargo easiest to tie down. An MB-1 chain devise should be used to restrain vehicle loads.   These   devises   should   be   fastened   to   the 10,000-pound tiedown fittings whenever possible. 6-6-53.  Bulk Cargo Tiedown. Typical methods of restraining large crates are shown in TM 55-450-2. If the crate is very heavy, an MB-1 tiedown devise should be used to provide forward restraint and should be fastened to the 10,000-pound tiedown fittings. 6-6-54.  General Cargo Tiedown. General   cargo   tiedown   methods   are   shown   in   TM 55-450-2. 6-6-55.  463  L  Pallet/Extended  Range  Fuel  System (ERFS). The  restraint  criteria  of  a  463L  pallet/ERFS  loaded  to 7,500 pounds is as follows. Direction Load Factor Forward 6g plus 1.5g down Aft 3g plus 1.5g down Lateral 2.25g plus 1.5g down Up 6g Down 3g NOTE The HICHS can yield locally under the above loads, but ultimate failure cannot occur; that is the cargo (e.g., pallet, ERFS) cannot be- come a flying object when the above loads are applied. The above ultimate load factors shall be applied to the entire HICHS. All other cargo will be restrained to the normal restraint crite- ria as stated in this chapter. 6-6-56.  Loading Sequence. Refer to table 6-4-2 to select the proper configuration for system components during loading. Up to three pallets may  be  winched  or  manually  loaded  on  the  system. Loading clearances are shown in figures 6-6-14, 6-6-15, and 6-6-16. 6-6-57.  Warehouse Pallets. Refer to table 6-4-2 to select the proper configuration for system components during loading. Up to 10 warehouse pallets can be loaded into the helicopter provided that the weight and C.G. requirements are within the limits speci- fied as follows. The 40- inch side should be positioned across the handling system so that the 48-inch side is on the outboard rail. Pallets may be winched or manually loaded. During loading, the pallet should be fork lifted onto the ramp extension and balanced onto the ramp rollers. On the ramp, it should be pushed on board. NOTE All cargo must be properly restrained to en- sure safe operation of the helicopter and safe- ty of personnel. Loads must be restrained in accordance with procedures and guidelines in TM 10-450-2, Helicopter Internal Loads. Individual warehouse pallets may weigh up to 3,700 lbs. However,  to  maintain  floor  isolation,  the  sum  of  the weights of longitudinally adjacent pallets must not ex- ceed 4,300 lbs. For example, pallets weighing 2,100 lbs or less may be loaded without discrimination; a mix of pallets weighing, for example, 3,000 lbs and 1,200 lbs, would require alternate loading of a 3,000 lb pallet and a 1,200  lb  pallet.  If  the  load  consists  entirely  of  pallets weighing  in  excess  of  2,150  lbs,  the  pallets  must  be spaced longitudinally such that the distance, in inches, between the forward edge of one pallet and the forward edge of one pallet and the forward edge of the subse- quent pallet will not be less than W/45.2 when W is the average pallet load in pounds. For example, load of pal- lets weighing 3,000 lbs each would need to be spaced 3000/45.2 = 66 inches center-to center apart. Pallets that are spaced longitudinally will require tiedowns for longi- tudinal, lateral, and vertical forces. In this situation there is no requirement to use the barrier systems. 6-6-58.  Wheeled Vehicles. Refer to table 6-4-2 to select the proper configuration for system components during loading. Winch or manually load the vehicles into the helicopter. 6-6-59.  Personnel. The Internal Cargo Handling System (HICHS), is com- patible for personnel only or for both cargo and person- nel. If both are loaded, the cargo should be forward of the personnel for safety. 6-6-60.  Miscellaneous Cargo. Place on a pallet or skid as desired. If a 6/E (463L) pallet is used, secure the pallet with the locks or retractable flanges. Straps or chains may be used as required. 6-6-61.  Mixed Cargo. Any of the previous cargos may be mixed as desired. The only limitation is space.