3.10. CLEANING COMPRESSOR ROTOR BLADES
When a particular engine's performance decreases to or below the point specified in the applicable TM, and the EGT increases steadily during normal operation, the compressor rotor blades need cleaning. Compressor rotor blades should also be cleaned whenever the engine has been operating in areas where the air is salt laden, or when the engine has been subjected to contamination with fire extinguishing agent residue (chlorobromomethane and soda ash). Cleaning can be accomplished while the engine is installed in the aircraft.
Before cleaning any engine the applicable engine technical manual must be consulted for the proper procedures to follow. On some engines, temperature and pressure lines must be disconnected and capped to prevent solvent and water from entering.
The following is the preferred method for cleaning the compressor on the T53-L-13. Refer to figure 3.7 as you read the following steps in the cleaning method.
a. Remove airframe air intake components as necessary.
b. Remove the inlet air-temperature sensing element from the inlet housing.
c. Disconnect the pressure line to bleed band actuator and cap the diffuser fitting with AN929-6 cap assembly.
d. Block off the customer bleed air supply at the customer airbleed port in the airbleed adapter assembly.
e. While the engine is cold, rotate it with the starter and spray one quart of dry-cleaning solvent (P-D-680 Type 1) evenly through all sections of the inlet housing. Make sure both sides of the inlet guide vanes are covered with solvent.
f. Stop motoring the engine and let it stand for at least one hour to permit the dry cleaning solvent to loosen dirt.
g. Clean the inlet guide vanes with a small, round fiber brush with a long handle.
h. Start the engine and operate it at flight idle.
i. Spray CLEAN fresh water evenly into all sections of the inlet housing at the rate of two gallons per minute for approximately two minutes. To avoid freezing at ambient temperatures below 35° F (1.5° C), use anti-detonating injection fluid or a mixture containing 40 percent methanol and 60 percent water in lieu of water.
j. Allow the engine to run for 2 to 5 minutes to dry out; then shut the engine down.
k. Inspect the inlet guide vanes and compressor for cleanliness.
l. Repeat the cleaning procedure if necessary.
m. Reconnect the lines for normal operation.
n. Clean the temperature sensing element with dry-cleaning solvent and reinstall it.
|David L. Heiserman, Editor||
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Revised: June 06, 2015