Turbine Engine Wet-Sump Lubrication  System Turbine Engine Oil System Maintenance In some engines, the lubrication system is the wet-sump type.  There are relatively few engines using a wet-sump type of  oil system. A schematic diagram of a wet-sump oil system  is shown in  Figure 6-47 . The components of a wet-sump  system are similar to those of a dry-sump system. The major  difference between the two systems is the location of the oil  reservoir. The reservoir for the wet-sump oil system may be  the accessory gear case or it may be a sump mounted on the  bottom of the accessory case. Regardless of configuration,  reservoirs for wet-sump systems are an integral part of  the engine and contain the bulk of the engine oil supply.  [Figure 6-47] is returned to the reservoir (sump) by gravity. Oil from the  compressor bearing and the accessories drive coupling shaft  drains directly into the reservoir. Turbine oil drains into a  sump where the oil was originally pumped. Included in the wet-sump reservoir are the following  components: Maintenance of gas turbine lubrication systems consists  mainly of adjusting, removing, cleaning, and replacing  various components. Oil filter maintenance and oil change  intervals for turbine engines vary widely from model to model,  depending on the severity of the oil temperature conditions  imposed by the specific airframe installation and engine  configuration. The applicable manufacturer’s instructions  should be followed. The oil filter should be removed at  every regular inspection. It should be disassembled, cleaned,  and any worn or damaged filter elements replaced. The  following steps illustrate typical oil filter removal cleaning  and replacement procedures: This system is typical of all engines using a wet-sump  lubrication system. The bearing and drive gears in the  accessory drive casing are lubricated by a splash system. The  oil for the remaining points of lubrication leaves the pump  under pressure and passes through a filter to jet nozzles that  direct the oil into the rotor bearings and couplings. The oil  1. A sight gauge indicates the oil level in the sump.  2. A vent or breather equalizes pressure within the  accessory casing. 3. A magnetic drain plug may be provided to drain the  oil and also to trap any ferrous metal particles in the  oil. This plug should always be examined closely  during inspections. The presence of metal particles  may indicate gear or bearing failure. 4.  Provision may also be made for a temperature bulb  and an oil pressure fitting. 1.  Provide a suitable container for collecting the drained  oil, if needed. 2.  Remove the filter housing and withdraw the filter  assembly.  [Figure 6-48]  Discard the old seals. 3.  Immerse the screen or filter in an approved carbon  remover at room temperature for a few minutes. Rinse  them in a degreaser fluid or cleaning solvent. Then,  blow them dry with an air jet. 4.  Then, install the filter in the filter housing assembly.  Place a new seal and tightened to the torque prescribed  in the manufacturer’s instructions.  5.  Secure with lock wire. Wet-sump Oil fill cap Sight gauge Figure 6-48. Oil filter housing.  Figure 6-47.  Typical turbine wet sump system.  6-32