the engine mounts) and all the disconnections are entirely  clear so they do not bind or become entangled, the engine  can be prepared for hoisting. Figure 8-8  shows the basic types of line disconnects. Most  lines leading from a QECA are secured to a threaded fitting  at the firewall by a sleeve nut around the tubing. Hoses are  sometimes secured in this manner but may also be secured  by a threaded fitting on the unit to which they lead, or by a  hose clamp. The firewall fittings for some lines have a quick- disconnect fitting that contains a check valve to prevent the  system from losing fluid when the line is disconnected. Metal  tubing on some installations may also be disconnected at a  point at which two lengths of it are joined together by a length  of rubber hose. Such a disconnection is made by loosening  the hose clamps and sliding the length of rubber hose over  the length of tubing that remains on the aircraft. There may  be some further variations in these types of disconnections,  but they follow the same basic pattern. If a QECA is being removed, the engine mount accompanies  the engine. The mount remains on the aircraft if only the  engine is being removed. Before the engine can be freed  from its attachment points, a sling must be installed so the  engine’s weight can be supported with a hoist when the  mounting bolts are removed. Aircraft engines, or QECAs, have marked points for attaching  a hoisting sling. The location of these attaching points varies  according to the size and weight distribution of the engine.  Figure 8-9  shows a sling supporting an engine that has two  attaching points. As a matter of safety, carefully inspect the  sling for condition before installing it on the engine. Some type of a container should be used to collect any fuel,  oil, or other fluid that may drain from the disconnected lines. After the lines have drained, they should be immediately  plugged or covered with moisture-proof tape to prevent  foreign matter from entering them, as well as to prevent any  accumulated fluid from dripping out. Before attaching the sling to the hoist, be sure that the hoist  has sufficient capacity to lift the engine safely. The engine’s  center of gravity (CG) should also be taken into account as  the engine is hoisted. A manually operated hoist mounted in a  portable frame is shown in  Figure 8-10.  This hoist assembly  is specifically manufactured for the purpose of removing  engines and other large assemblies from aircraft. Some  frames are fitted with power-operated hoists. These should  be used with care, since considerable damage can be done  if an inexperienced operator allows a power-operated hoist  to overrun. The hoist and frame should also be checked for  condition before being used to lift the engine. The points at which the various air ducts are disconnected  depend upon the engine and the aircraft in which it is  installed. Usually, the air intake ducts and the exhaust system  must be disconnected so the basic engine or the QECA can  be removed. After the engine connections are free (except  Removing the Engine Other Disconnections Figure 8-9.  Hoisting sling attached to engine.  Figure 8-8.  Types of line disconnects. 8-9 Engine lifting point Engine lifting point Sleeve and nut fitting Threaded fitting and receptacle Hose clamp and fitting Interconnecting hose