service-life limitations, and all safety precautions. The AME who understands the importance of all of  these  factors  and  who  correctly  uses  the maintenance manuals is better equipped to super- vise and train others. Always refer to the manual, Cartridges   and   Cartridge-Activated   Devices (NAVAIR  11-100-1).  The  manual  contains cartridge  information  and  safety  precautions  for handling  explosives. Initiators As previously discussed, initiators, such as the M99,  start  an  action.  Initiators  are  explosive devices,  and  no  maintenance  is  allowed  on explosive  devices.  When  installing  explosive devices or during aircraft inspections, initiators will  be  verified  for  expiration,  and  if  newly installed they will be marked with an approved marking medium with all the information required by the cartridge manual, NAVAIR 11-100-1. Delay initiators serve the same function as initiators, but they have a built-in delay charge to allow another function to be performed before they fire. An example would be a 0.5-second delay initiator installed in the line to the rocket motor of the forward seat in a two-place aircraft. This would allow the rear seat to clear the aircraft first by   delaying   the   firing   of   the   forward   seat ejection rocket for 0.5 second. Detonating Cord Detonating cord is installed between different components  of  an  ejection  system,  taking  the place of pneumatic gas lines. The detonating cord is a stainless steel tubing filled with an explosive, and   is   more   reliable   and   much   faster   than comparable  pneumatic  gas  systems.  The  system is also safer from the standpoint of inadvertent actuation  due  to  the  extremely  high  initiating velocities,  and  pressures,  as  previously  discussed. Rocket  Catapult The rocket catapult, MK 16 MOD 1, used in the S-3 aircraft is rated as a class B explosive. The MK 16 MOD 1 is a self-contained, gas-initiated, two-phase, solid-propellant booster and rocket. The  rocket  catapult  consists  of  two  gas-initiated firing  mechanisms,  a  solid-propellant  booster assembly, a rocket launching tube, a gas-initiated rocket igniter, a solid-propellant rocket motor, and an output cartridge for actuation of other gas initiated  escape  devices. Each firing mechanism consists of one firing pin  (shear  pinned  in  place)  mounted  inside  a special fitting that combines the inlet port and firing  mechanism  housing.  Two  inlet  port/firing mechanism  housings  are  threaded  into  each  base cartridge  assembly. The catapult tube assembly consists, primarily, of  a  cartridge  assembly,  lock,  unlock  sleeve, unlock  piston,  unlock  spring,  outer  housing, motor  lock  disk,  mounting  bracket,  and  front body housing. The rocket motor assembly consists, primarily, of a steel motor tube with canted nozzle assembly and a tungsten insert, a solid-propellant grain, an ignition charge, an output cartridge assembly, and a seat mounting lug to facilitate attachment to the aircraft ejection seat. FUNCTION.—  When  the  aircrewman  pulls the face-curtain ejection handle or the alternate ejection handle or when the sequential ejection system is actuated, an external initiator begins the catapult  operation  by  forcing  gas  through  the inlet  fitting(s)  into  the  cartridge  assembly  of  the rocket catapult. This gas pressure provides the force necessary to shear the pins that hold the rocket catapult firing pins in place. The firing pins then  develop  the  energy  necessary  to  fire  the percussion primers in the cartridge assembly. The percussion primer then fires the ignition material within  the  cartridge  assembly,  which,  in  turn, ignites the booster cartridge. The piston unlock ring  then  moves  downward,  compressing  the unlock spring and releases the lower tangs of the lock  assembly. After the lower tangs of the lock assembly have been released, movement of the rocket motor assembly begins. As gas from the main cartridge charge expands and drives the assembly up the catapult tube, the nozzle is kept sealed by the motor  lock  disk.  Near  the  end  of  the  catapult stroke,   the   motion   of   the   unlock   sleeve   is stopped  by  interference  with  the  front  body housing, and the shear pins between the unlock sleeve and the rocket motor assembly are sheared. At this point, the rocket motor has achieved a velocity of approximately 50 feet. per second. When  the  rocket  motor  has  traveled  another 6-24