handle from the EMERGENCY position until directed to do so by the catapult officer. • No person is to perform any actions required by the main-control-console operator. Under no circumstances is the shuttle to be maneuvered aft before the launching valve cutout valve is rotated to the EMERGENCY position, as such action can cause an accident. • The catapult crew must not approach the aircraft until it has been UNTENSIONED and is clear of the shuttle throat. After the launch bar has been raised, the catapult officer gives the THROTTLE BACK signal to the pilot, and the aircraft is removed from the catapult. WARNING The launching officer should not signal the pilot to THROTTLE BACK until he or she has positively determined that the catapult shuttle is forward of the launch bar, except for the following emergency condition: If the launch bar cannot be raised without sending personnel under the turned-up aircraft, the launching officer should positively determine that the catapult is in the safe condition, then step in front of the aircraft wing and give the THROTTLE BACK signal to permit safe removal of the aircraft. CAUTION After the aircraft is removed from the catapult, reduce the steam receivers to no-load pressure; then operate the control system through the entire operating cycle to determine and eliminate the cause of hangfire before continuing launchings. INTERMEDIATE LAUNCHINGS.— Intermediate launchings are carried out in the same general manner as the first launching. If the catapult is being operated as one of the interlocked pair, the first catapult to reach STANDBY is fired first. Care must be taken through a prolonged series of launchings to make sure the cylin- der elongation is maintained as prescribed by NAEC. Operate the water-brake pump to obtain desired vacuum and water pressure. Maintain the level of the water in the water-brake reservoir within 6 inches of the safety screen. Maintain the water tank temperature between 40 and 180°F. If water in the tank rises above 180°F, add water through the tank fill lines. Drain off hot water through the tank overflow line. Maintain the water-brake pumps in operating condition. The bearing temperature should not exceed 180°F. Watch for a sudden rise in temperature. Gland leak-off is to be several drops per minute, but there must not be an excessive flow. Maintain a close watch of the inlet elbow pressure. An increase of 10 psi above normal operating pressure or a maximum of 70 psi indicates a possible restriction in the annulus ring and calls for a shutdown for investigation. Maintain proper charging pressures in all parts of the hydraulic system throughout a series of launchings. Adjust pressure as required to maintain at predetermined settings. Monitor the entire catapult system closely for broken or loose parts, the piping and valves for leaks, and the cable system for damage and wear. Keep all tools and loose gear clear of the retraction engine and cable system. Maintain a close watch on all temperatures; adjust as required to maintain at prescribed settings. Watch all equipment located in the control console room closely. Check for loose nuts and bolts, leaks in valves and piping, and any malfunction in the operating units. Operation of the catapult must be conducted with steam pressures prescribed by the catapult officer. Maintain steam receivers at launching pressure as specified by the catapult officer. Maintain communication with all stations. Keep a catapult log at the control console, and keep the shot logs up to date. LAST LAUNCHING. —Certain procedures must be followed to secure the catapult after the last aircraft is launched. Under normal operating conditions, the catapult must always be secured with the pistons bottomed in the water brakes and with the pumps secured. 4-70