MAINTENANCE OF GAS TURBINE
lifting adapter to the top of the engine. Using an
COMPRESSORS
overhead crane or hoist, carefully raise the engine
enough to remove the slack from the linkage. Then,
remove the engine attaching bolts from the engine
LEARNING OBJECTIVE: Identify
mounting pads, attach maintenance stand mounts, and
procedures for performing maintenance on gas
turbine compressors.
place the engine in a maintenance stand.
Replace the gas turbine engine in the reverse order
Gas turbine compressors are precision units that
of the procedure you used to remove it from the
require special tools and testing devices, which are not
enclosure. Ensure that new gaskets and packing are
available at the lower levels of maintenance. There are
used at all connections.
also special requirements as to cleanliness and
availability of power. For these reasons, maintenance
GENERAL CLEANING PROCEDURES
i s n o r m a l l y p e r f o r m e d a t i n t e r m e d i a t e - l eve l
maintenance activities.
Electrical parts may be cleaned with a soft cloth
dampened in an approved solvent. A clean, dry,
Maintenance of the engine often requires the use of
soft-bristle brush may also be used. When using a
a hoist, or some type of chain fall, to lift the engine in
solvent, make sure you keep the area well ventilated
and out of its enclosure or to place it in a shipping
and avoid breathing the fumes. Do not use solvents in
container. As there is no specific hoisting device
the vicinity of open flames. Metal parts and tube
named in the instructions given in the MRCs, the crew
assemblies may be cleaned by dipping the parts in
leader is normally responsible for selecting a type that
solvent, and then drying them thoroughly with clean
a l l ow s t h e m a i n t e n a n c e t o b e p e r f o r m e d w i t h
compressed air. Air, fuel, or oil passages in removed
maximum safety of the crew. Also, the special lifting
components may be blown clean with compressed air,
adapter, which is supplied with the unit, may not be
but you must take care to direct the air blast away from
replaced with a substitute. These adapters are made for
personnel and equipment.
use with the specific unit, and substituting an improper
To remove hard carbon deposits from components,
adapter can cause imbalance during hoisting, leading
use one of the approved decarbonizing agents. Consult
to the unit being dropped. This will certainly damage
the appropriate maintenance instruction. Use of
the unit, and may cause injury to the crew.
sandpaper, wire bristle brushes, or scraping tools is
R e m ova l a n d i n s t a l l a t i o n o f g a s t u r b i n e
strictly prohibited. When the clean parts are not used at
compressors demand an alert crew. Each step of the
once, they should be placed in clear plastic bags to
procedure must be performed in strict accordance with
prevent corrosion and contamination.
the instructions provided in the appropriate manual or
MRCs for the type of unit being maintained.
MINOR REPAIR AND ADJUSTMENT
REMOVING AND REPLACING GAS
Most repairs to the gas turbine compressor involve
TURBINE ENGINES
the removal of major components. This consists
principally of disconnecting electrical and tubing
Replacement of gas turbine engine components
c o n n e c t o r s , r e m ov i n g a t t a c h e d h a r d wa r e , a n d
does not necessarily require the removal of the engine
withdrawing the component from the unit. All
from the enclosure. Many components are accessible
removals should be done in keeping with good shop
through access panels and doors. However, many
practices.
circumstances require the removal of the gas turbine
Some parts require only minor repair, which may
engine from the unit.
consist of inspection, repair, and cleaning faulty
Access to the gas turbine engine for removal can be
components. Consult applicable maintenance manuals
obtained by first removing the enclosure from the
for procedures pertaining to adjustments and repair.
tractor (if so mounted). Ensure the enclosure is placed
Q12-19. What is the recommended cleaning method
on a suitable support fixture to provide access to the
for electrical parts?
bottom of the unit.
1.
Use a soft cloth and cleaning solvent
After following the steps in the appropriate
2.
Use a wire brush
operation and maintenance manual for disconnecting
3.
Use sandpaper
enclosure ducting, air, fuel, and oil hose assemblies, as
4.
Use a scraping tool on heavy buildup
well as all electrical connections, attach the engine
12-28
