Abstract :
Aircraft must pay attention to all aspects of maintenance and maintenance
for safety and comfort when the aircraft is operating. The slightest damage to an
aircraft can jeopardize the safety of passengers during flight. The pneumatic system
works by supplying compressed air to the aircraft, where the pneumatic system has
a power source that comes from APU (Auxiliary power unit)¸ Engine Bleed air,
Pneumatic Ground air connection. One aspect of aircraft safety that needs to be
considered is the supply of air into the cabin so that there is no low duct pressure.
There are 3 distribution approach methods, namely using the exponential
distribution method, Weibull distribution, and Lognormal Distribution. In
performing the calculation the author uses a distribution with an Index Of Fit value
close to 1 and is used to calculate the reliability value. A reliability Block Diagram
(RBD) is a method to perform system reliability and availability on large and
complex systems using system block diagrams (Ebeling, 1997). RBD is also known
as a dependency diagram An RBD is taken as a series of connected blocks in
parallel or series configuration.
Based on the results of data processing that has been done, 7 components are
obtained that cause low duct pressure, namely High Stage Valve, Precooler Control
Sensor (390f), Prsov, Bleed Air Regulator, 450 F Thermostat, High Stage
Regulator, Precooler Control Valve. Then calculate the component reliability value
and obtain the reliability value of the BAR component (0.3464%), HSR (0.3707%),
HSV (0.8212%), 450 F Thrmst (0.6421%), PRSOV (0.7255%), PCV 390F
(0.6380%), PCV (0, 5644%) combined reliability value with RBD series series
results obtained Rseri Based on the calculation results, it can be known under the
reliability value for the pneumatic system that causes low duct pressure which
without involving APU is 0.177%.