INTERMEDIATE GEARBOX (NAVY ONLY)

NAVAIR 17-15-50.3

TM 38-301-3

T.O. 33-1-37-3

CGTO 33-1-37-3

H-53

INTERMEDIATE GEARBOX (NAVY ONLY)

JOAP ATOMIC EMISSION ROTRODE

Abnormal Trend

(PPM Increase

in 10 hrs)

Normal Range

0-46

0-13

0-20

Marginal Range

47-56

14-16

21-25

High Range

57-69

17-19

26-30

Abnormal

70+

20+

31+

Average Concentration Other Elements:

Water Limit: 1,000 ppm or 0.100% (if equipment is available at lab)

Water in the oil could cause high iron, copper, magnesium, or aluminum due to corrosion. If high or abnormal

wear metals are obtained and high water is detected on two consecutive samples, the laboratory

recommendations may be to drain gearbox, reservice and perform serviceability check. Info CFA when

recommending flushing.

NOTE

Special samples may be recommended anytime unusual readings are obtained.

High metal readings without high water may result in a laboratory recommendation for flushing or removal of a

gearbox. A minimum of two consecutive high readings is required prior to recommending flushing or removing

gearbox unless other evidence (chiplights, fragments, unusual noise, etc.) is found. Info CFA when

recommending flushing. CFA concurrence is required prior to a recommendation for gearbox removal due to high

readings. Furnish CFA with 5 previous NOAP readings when recommending gearbox removal.