0.9 inch (approximately), the shoulder on the lock strikes  the  immobilized  unlock  sleeve  and  stops. This action releases the upper tangs of the lock and  unseals  the  rocket  motor  nozzle  by  severing the nozzle plug and retaining the motor lock disk. The hot, pressurized gases from the cartridge then pass into the rocket motor assembly through the nozzle. These gases energize the rocket motor firing  mechanism,  which  ignites  the  rocket  igni- tion material. The rocket ignition material and/or the hot gases from the booster cartridge ignite the rocket motor solid-propellant grain. The rocket motor then provides additional thrust to the air- crewman seat after separation of the booster and rocket  sections. The  rocket  motor  internal  pressure  energizes two output cartridge firing mechanisms that fire the output cartridge. The output cartridge then actuates other escape devices, which are attached to  the  output  fitting. INSPECTION OF THE ROCKET CAT- APULT.—  The rocket catapult must be inspected whenever  it  is  removed  from  the  shipping container  for  use  and  prior  to  returning  it  to stowage.  If  the  rocket  catapult  is  found  in  a hazardous  condition,  explosive  ordinance  disposal (EOD) personnel must be immediately notified. After the rocket catapult is rendered safe, or if it  is  rejected  for  any  other  reason,  it  must  be disposed of in accordance with NAVAIR 11-85-1. Inspect the rocket catapult for damage, such as dents and corrosion; reject the unit if it has any visible  defects.  Inspect  the  head  end  cap  for tightness  by  grasping  the  cross-shaped  head  end trunnion (word AFT stamped on face) with one hand and attempt to tighten the head end cap with the other. If any cap motion is detected, do not reject  the  unit  but  repair  it  in  the  following manner. Back off head end cap until the U-shaped slot in the rocket motor tube is exposed. Inspect to see if the head end trunnion pin is completely contained within the U-shaped slot. If the entire pin is not visible within the slot, reject the unit. NOTE: Pin is not necessarily bottomed in the slot. If   unit   passes   inspection,   apply   Locktite (grade N) to exposed thread area, hand tighten cap,  and  then  tighten  with  strap  wrench.  Inspect the  adjustment  ring  for  tightness  by  grasping  the cross-shaped   head   end   trunnion   (word   AFT stamped on face) with one hand and attempt to tighten the adjustment ring with the other. If more than a few degrees of side-to-side play is evident in  adjustment  rings  with  six  holes  (two  con- figurations of adjustment rings are in service— one with six holes and one without holes), reject the unit. If the adjustment ring without holes is found to be loose, do not reject the unit but repair it in the following manner. Back off the adjustment ring until it contacts the  head  end  cap,  and  apply  Locktite  sealant (grade N) to the exposed, degreased thread area. Ensure that the front body housing is tightened down  against  the  catapult  tube  prior  to  hand tightening the adjustment ring against the front body  housing.  Allow  Loctite  sealant  to  set. Reinspect prior to use. MARTIN-BAKER  SJU-5/A EJECTION  SEAT Learning Objective: Recognize the com- ponents, seat system/subsystems, support components,  system  operations,  compo- nent test and test equipment, and corrosion control procedures for the Martin-Baker SJU-5/A   ejection   seat. The   SJU-5/A   ejection   seat   is   a   ballistic catapult and rocket system that gives the pilot a quick and safe means of escape from an aircraft. The seat system includes an initiation system that jettisons   the   canopy,   positions   the   pilot   for ejection,  and  fires  the  seat  catapult.  Canopy breakers  on  the  top  of  the  seat  allow  the  seat capability to eject through the canopy should it fail to jettison. As the seat ejects from the aircraft, a rocket motor on the bottom of the seat is fired. Then a  drogue  gun  is  fired  to  deploy  two  drogue parachutes.  These  parachutes  either  remain attached to the top of the seat or they are released to deploy the main parachute, depending upon the altitude and the number of g’s applied to the seat.  An  automatic  time-release  mechanism  opens the  main  parachute  container  and  releases  the drogue   parachutes   that   deploy   the   main parachute. 6-25