a. Prepare two to four quarts of cleaning solution con-
sisting of one part cleaning compound (items 39, 40, 41,
42, table 2-2) to four parts of clean water (distilled if
Do not substitute petroleum base solvent or
jet fuels for recommended cleaning com-
pound. Damage to compressor plastic lining
b. Retain the anti-icing air valve in the closed posi-
c. Inspect P
tube at scroll and filter ends for cracks
and fretting wear. Closely check the areas covered by
the floating ferrules and the flared ends. Inspect the
scroll for cracks at the junction with P
d. Disconnect the control air and compressor bleed
valve pressure sensing tubes at the diffuser scroll pres-
sure probes. Cap both pressure probes and plug all open
sensing lines. Block the compressor bleed valve in the
closed position using the compressor protector cleaning
kit, tool No. 68886204. (See figure 2-4.) Refer to TM
55-1520-228-23 for airframe bleed air operated sys-
e. Remove the burner drain valve (14, figure 3-8) from
the bottom drain port on the outer combustion case.
f. Deactivate the ignition system by diconnecting the
power lead to the ignition exciter or pull engine ignition
Do not exceed 10% N1 motoring speed dur-
ing the cleaning and rinsing cycles to prevent
possible blade damage and assure adequate
rinse/cleaning at the base of the blades. Do
not inject a solid stream of fluid into the com-
pressor. Damage to compressor could occur.
g. Spray cleaning solution into the compressor inlet
using a low pressure type sprayer equipped with a quick
opening valve while motoring the engine without igni-
tion. Start injection 3 seconds prior to starter engage-
to 11 seconds until 2 to 4 quarts (1.9 - 3.8) have been
utilized. Maintain motoring speed below 10% for the
duration of the injection. Disengage the starter if N1
speed is attained. Repeat the injection cycle as ceces-
sary until the compressor is clean.
h. Within 15 minutes after injection of the cleaning
solution, spray clean water (distilled preferred) into
compressor. Use methanol water mixture if ambient
temperature is below 4°C (40°F). Start injection 3 se-
conds prior to starter engagement and inject steam or
water at the rate of one pint to one quart in 5 to 10 se-
i. Remove the compressor protector cleaning kit and
reconnect the control and compressor bleed valve sens-
ing tubes. Tighten the coupling nuts to 80 - 120 in. lb.
j. Reconnect the power lead to the ignition exciter or
reset the IGN ENG circuit breaker.
k. Apply antiseize compound (item 15, table 2-2) to
the threads and install burner drain valve (14, figure 3-8)
with new preformed packing (13) in the bottom drain
port of the outer combustion case. Tighten the drain
valve to 120 - 140 in. lb. Apply antiseize compound
(itm 15, table 2-2) to the threads on the outer end of the
drain valve. Secure clamp and bracket assembly (15) to
the drain valve with jam nut (16). Tighten the jam nut
to 55-80 in. lb. and secure with lockwire (item 32, table
l. Start and operate the engine for a minimum of five
minutes. Operate the engine anti-icing system to purge
solution from the compressor front support. Also, oper-
ate any aircraft systems which use compressor bleed air.
Complete the engine drying run within 15 minutes after
cleaning and rinsing. Using the soap solution, mainte-
nance operation check (MOC) is required to verify that
the reconnected P
line and bleed valve line do not leak.
An EPC and torsional oscillation check is not
required for routine 50 hour engine flushes
unless poor engine performance is noted.
7-4. Compressor Rinsing to Remove Salt Water
Allow the engine to cool for a minimum of 45
minutes prior to spraying the compressor.
Mandatory cooling period is required to
prevent warpage to internal engine compo-
The compressor shall be rinsed if operated within 200
miles of volcanic activity or operated within 10 miles of
salt water and on all engines operated below 1000 feet
(304.8m) over salt water shall overgo cleaning accord-
ing to the following procedure after shutdown following
the last flight of the day. Use the procedure in paragraph
7-3 with the following additions.
If any cracks in the Pc tube, ferrules, flared ends
and elbow P
elbow junction is suspected, refer
to TM 1-1520-254-23, Technical Manual Aviation
Unit Maintenance (AVUM) and Aviation Intermediate
Maintenance (AVIM) Manual Nondestructive Inspec-
tion Procedure for OH-58 Helicopter Series.
conds. Disengage the starter before N1 speed
accelerates above 10 .