Q4. When used on F-14 aircraft, where is the M61A1 gun system mounted? Q5. What is the maximum capacity of the gun system when used on the F-14 aircraft? MAINTENANCE AND TESTING LEARNING OBJECTIVE: Identify main- tenance and testing procedures at the organizational and intermediate levels. The maintenance and testing responsibilities of an M61A1 gun installation are distributed evenly between the organizational and intermediate levels of maintenance. The basic responsibilities of these two levels of maintenance are discussed in the following paragraphs. ORGANIZATIONAL MAINTENANCE Organizational maintenance includes servicing (loading and unloading), preflight, postflight, minor periodic maintenance, malfunction troubleshooting, and removal and installation of components on the aircraft. Also, maintenance of the aircraft system and controls must be included in the AO’s organizational responsibilities. The gun firing record or log is kept at this level. The cumulative total of rounds fired is the basis for most of the maintenance. The number of rounds fired per firing flight is obtained from a counter located within the aircraft. For record accuracy, each time the gun installation is loaded, the counter must be reset (usually to zero) according to the instructions applicable to the aircraft. The two primary tasks that depend upon the round interval (rounds fired) are (1) torquing the two forward front track bolts (30,000 rounds), and (2) changing the breech-bolt assemblies (15,000 rounds). Organizational responsibilities are not included in  NAVAIR  11-95M61A1-1  or  the  NAVAIR 11-95M6lA1-2. Organizational responsibilities are outlined in MRCs, aircraft MIMs, and aircraft loading manuals. If a component is being removed for sudden stoppage (jam) maintenance, be careful and take extra precautions. Loose propellant powder from ruptured cartridge cases may be scattered about the gun compartment. This creates an extremely hazardous situation. The loose powder must be removed in a RADHAZ-free environment before you begin to remove a component. INTERMEDIATE MAINTENANCE Intermediate maintenance responsibilities are tasks associated with repair or replacement of unserviceable or damaged assemblies, components, or parts of the gun installation that do not require the special maintenance facilities of an overhaul depot. When a gun reaches a round interval of 120,000 rounds fired or requires major repair or alteration, it is sent to a depot-level maintenance activity. The ammunition handling and gun drive system maintenance procedures are identical at both the intermediate- and depot-maintenance levels (with one exception, the depot level removes bearings); therefore, such maintenance is generally performed at the intermediate level. Intermediate maintenance may be divided into two categories—scheduled and unscheduled. Scheduled maintenance includes inspecting, disassembling, replacing parts, lubricating, assembling, and functionally checking components based on the round interval specified in technical manuals. Scheduled gun maintenance begins at 15,000 rounds and proceeds through various interval states for different parts replacement up to the 120,000-round overhaul interval. Scheduled maintenance for the handling and drive system is set at an interval of 30,000 rounds. REVIEW NUMBER 6 Q1. The breech bolts are changed out when what number of rounds have been fired from the M61A1 gun system? Q2. What is the overhaul interval for the M61A1 gun ? Q3. At what interval should scheduled maintenance for the handling and drive system be done? SAFETY PRECAUTIONS LEARNING OBJECTIVE: Identify safety precautions to follow when working with the M61A1 gun. The weapons systems described in this chapter are safe systems. Live rounds are isolated from the firing circuits except when the gun system is deliberately being fired. The gun system is RADHAZ safe and completely shielded from radiation fields. The gun is charged and cleared in flight, so the aircraft can takeoff and land without live rounds in the firing position. Although the sole purpose of all ordnance is to destroy 6-18