precautions are recommended safety precautions that all personnel should follow when operating and maintaining equipment.   All  persons  who  supervise  or  perform  work  in connection with ammunition handling should be familiar with the United States Ordnance Safety Precautions, NAVSEA OP 3347.   When    test    firing    is    conducted    using    live ammunition, observe all existing range regulations.   Before  undertaking  any  operation  for  which  a check off list exists, the check off list is read so all personnel know what to do.   When  provided,  always  use  safety  devices  to prevent  accidents.  Keep  safety  devices  in  good operating order at all times.   Do   not   make   changes,   modifications,   or additions  to  a  weapons  system  without  prior approval and authorization from the appropriate authority.   A    hazardous    condition    exists    if    a    gun malfunction occurs and there is anything in line with  the  gun  muzzle.  Observe  area  clearance requirements during maintenance periods.   Percussion can fire electrically primed ammunition.   NEVER   cycle   live   ammunition through a gun for testing purposes.   The  explosive  elements  in  electric  primers  are highly  sensitive  to  static  electricity.  Make  sure the  primer  button  does  not  come  into  contact with the human body.   Observe   fire   regulations   and   maintain   good ventilation  when  using  cleaning  solvents  and other volatile maintenance materials.   Before performing maintenance actions involving  pneumatic  or  hydraulic  pressurized components, ensure that all pressure is removed and   the   component   is   in   the   safest   possible condition. REVIEW NUMBER 7 Q1. If a check off list is to be used during an operation, what action must take place first? Q2. To prevent explosive primers on gun ammunition   from   being   exposed   to   static electricity, what action should be taken? Q3. When does a hazardous condition exist? REVIEW NUMBER 5 ANSWERS A1. In  F/A-18  aircraft,  fired  projectiles  exit  the aircraft through the gun blast diffuser assembly  that  is  located  just  forward  of  the cockpit windscreen. A2. When  used  on  the  F/A-18  aircraft,  the  gun system holds a maximum of 578 rounds. A3. A round limiter, located in the gun compartment, can be preset to limit the total number of rounds the pilot can fire. A4. When used on F-14 aircraft, the M61A1 gun system is mounted in the forward fuselage on the left side of the aircraft. A5. The  maximum  capacity  of  the  gun  system used on the F-14 aircraft is 676 rounds; 576 rounds  in  the  drum  and  100  rounds  in  the chute. REVIEW NUMBER 6 ANSWERS A1. The   breech   bolts   are   changed   out   when 15,000   rounds   have   been   fired   from   the M61A1 gun system. A2. The  overhaul  interval  for  the  M61A1  gun  is 120,000 rounds. A3. Scheduled maintenance for the handling and drive  system  of  the  LALS  should  be  done when the gun has fired 30,000 rounds. REVIEW NUMBER 7 ANSWERS A1. If  a  check  off  list  is  to  be  used  during  an operation,  it  must  be  read  to  all  personnel who will take part in the operation. A2. To prevent explosive primers on gun ammunition   from   being   exposed   to   static electricity,  make  sure  that  the  primer  button of the ammunition doesn't come into contact with the human body. A3. A    hazardous    condition    exists    if    a    gun malfunctions  and  there  is  anything  in  line with the gun muzzle. 6-19