Abstract :
The APU is an important part of the Boeing 737-800NG aircraft which is
located at the tail of the aircraft and functions as a generator of electricity and
pneumatic power (compressed air) for starting the engine when the aircraft is on
the ground. Examination of the APU is carried out during scheduled maintenance
in hangar 4 PT. GMF AeroAsia. When the aircraft performs engine run up, a
message fail occurs in the form of a P5 MAINT light indicator on the auxiliary
power unit, and it is seen that there is oil dripping from the aft drain section of the
APU.
The method used in solving the high oil consumption problem is a
qualitative method by performing Troubleshooting of high oil consumption which
refers to the Fault isolation manual (FIM) 49-95 task 801.
The cause of the APU high consumption oil is an increase in oil
consumption that exceeds the limit allowed on the AMM, the increase in oil
consumption occurs due to damage to the Oil cooler component. In the Oil Cooler
component there is a problem of damage to both the packing on the supply and
return tube. The occurrence of damage to the packing can be caused by a long
period of use which causes a decrease in the strength of the packing to withstand
leakage at the tube connection.