Institusion
INSTITUT TEKNOLOGI DIRGANTARA ADISUTJIPTO
Author
FAJAR ASTRA WIJAYA, SATRIYO
Subject
T Technology (General)
Datestamp
2024-06-05 09:04:58
Abstract :
Pneumatic system is a system for passing Bleed air (compressed air) to Stage 5 and
Stage 9 which is taken from the Engine compressor or from the APU or from the Ground
cart. The air is distributed from the Pneumatic manifold for use in air conditioning packs,
wings and thermal anti-ice (TAI),Engine starting systems, Potable water systems and for
hydraulic reservoirs. The main supply of Bleed air to the Manifold is obtained directly from
the Engine stage 5 compressor.
A failure in the process pnuematic system can be seen by identifying and testing it.
Normally the pressure is on the indicator bleed trip of 18 psi, but the pressure on the
indicator is 10 psig. This results in a low duct pressure pnuematic which can interfere with
theprocess pneumatic system. The result of the low duct pressure is the reducedpressure air
conditioning to cool the cabin to be not optimal.
There is a brittle part of the braided flex sense line / flexible house on the precooler
control valve and when viewed from the schematic of the pnuematic system on the flexible
house, it experiences leakage. So that the pressure that passes through the precrooler control
valve results in low duct pressure. After knowing the problem, do the troubleshooting,
according to the procedure of the AMM Boeing 737-300 /(Aircraft Maintenance
Manual400/500) with reference number 32-11-05 page 117. Efforts are made to overcome
problems that cause low duct pressure pnuematic by replacing it withcomponents flexible
house to return toconditions serviceable.