|
|
NAVAIR 17-15-50.3
TM 38-301-3
T.O. 33-1-37-3
CGTO 33-1-37-3
ENGINE:
TF33-PW-102, JT3D-3B
AIRCRAFT:
(C-18) (C-135) (C-137) (E-8)
JOAP ATOMIC EMISSION ROTRODE
Fe
Ag
Al
Cr
Cu
Mg
Ti
Abnormal Trend
(PPM Increase
4
2
2
3
2
2
3
in 10 hrs)*
Normal Range
0-2
0-1
0-1
0-1
0-1
0-1
0-2
Marginal Range
3-9
N/A
2-3
2
2
2
3
High Range
10-24
2
4
3
3
3
4
Abnormal
25+
3+
5+
4+
4+
4+
5+
Average Concentration Other Elements:
Ni=1
Pb=1
Si=2
Sn=6
Mo=1
*
If the calculated PPM trend value is equal to or greater than the trend PPM value limit, the engine has an
abnormal trend.
Sudden increase in Mg indicates discrepancy in the accessory gearbox. All bearing journals except those that are
titanium may be chrome plated during rework. Increases in titanium indicate bearing inner race turning on journal
or hub.
NOTE
TF33 engines that have experienced a rise in magnesium only may be returned to
service after accomplishing the following procedures:
1. Establish that magnesium is the only metal that is experiencing an increase (Si
does not apply to this). Most likely cause is oil relief valve rubbing. Shim is available to
stop valve contact to eliminate the need for the following, recurring drain and flush.
2. Drain all oil (main) from the engine.
3. Inspect oil filter and sump screen for contaminants.
4. Inspect the front gearbox assembly (front door) for any signs of abnormal wear.
5. If the above procedures check ok, then fill the engine with oil and perform a run to
reestablish the baseline.
6. Take a JOAP sample and if limits fall within parameters, the engine may be
returned to service.
7. A follow-up JOAP must be taken after the first five hours of engine operation.
8. Follow any command guidance in reporting high magnesium occurrence.
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |