follow when working with these fuzes. Refer to figure 13-6 for arming wire installation. MK 376 ELECTRIC TAIL FUZE.— Prepare, inspect, and install the fuze as follows: 1. Ensure that the safety pin is installed in the pop-out pin. 2. Remove shipping cap. 3. Ensure moisture or foreign material is not present in the electrical connector at base of fuze. 4. With thumb, push in on pop-out pin, remove safety pin from pop-out pin. 5. Ascertain if resistance from pop-out pin against thumb is present. 6. Reinstall safety pin into pop-out pin. 7. Loosely install fuze restraining clip on the flange of the fuze. 8. Install fuze into tail fuze well, and tighten with spanner wrench until flange is seated. 9. Align pop-out vertical with bomb lugs; tighten fuze restraining clip. FMU-139 ELECTRONIC TAIL FUZE.— Prepare, inspect, and install the fuze as follows: 1. Ensure that gagrod is secured by safety pin. 2. Verify that red and black striping is not visible on gagrod sleeve. 3. Check fuze for exterior damage, moisture, and corrosion. 4. Remove plastic shipping plug and flag from connector on the end of the fuze. 5. Set the fuze switches as follows: a. Check that the low-drag arm/delay fire switch is set to X-position. b. Rotate high drag arm/delay time switch as required. It must be in a 2.6 sec position for Navy/Marine aircraft. 6. Align faceplate with bomb lugs. Insert fuze into tail fuze well. 7. Install and tighten closure ring. The fuze may spin slightly. Mk 122 Arming Safety Switch Remove, inspect, and install the Mk 122 arming safety switch as follows: 1. Remove the Mk 122 arming safety switch from its package. 2. Inspect the Mk 122 arming safety switch for deformation, corrosion, and damage to the case. Check the contact assembly for cleanliness. Check the coaxial cable for cracks and breaks in the insulation, and be careful not to stress the coaxial cable. 3. Install the Mk 122 safety arming switch as follows: WARNING The Mk 122 arming safety switch must be installed in a RADHAZ-free environment Do not pull the lanyard during handling and loading. If the lanyard breaks away from the switch, discard the entire arming safety switch so it will not be used on a bomb. Do not attempt to replace the lanyard. CAUTION When installing or removing the weapons carrier and while handling the weapon, be particularly careful to avoid damaging the safety switch. When using a Mk 49 Mod 1 weapons carrier, do not install the safety switch until the weapon has been positioned on the skid adapter. Failure to orient the switching unit retaining nut can result in damage to the arming safety switch. a. Plug the male connector of the switching unit firmly into the bomb charging receptacle, piercing the diaphragm. Then, slide the switching unit retaining nut, threads down, over the cable and lanyard. b. Secure the arming safety switch in the bomb charging receptacle by screwing the switching unit retaining nut into the bomb and tightening it with the wrench supplied. When the nut is seated on the top of the switching unit, back it off until the flattened sides of the switching unit retaining nut are at right angles to the length of the bomb and the coaxial cable is aft of the lanyard. c. Insert the free end of the cable through the nearest bomb suspension lug to safeguard the cable. 13-6