TAIL ROTOR GEARBOX (NAVY ONLY)

NAVAIR 17-15-50.3

TM 38-301-3

T.O. 33-1-37-3

CGTO 33-1-37-3

SH-2G

TAIL ROTOR GEARBOX (NAVY ONLY)

JOAP ATOMIC EMISSION ROTRODE

Abnormal Trend

(PPM Increase

in 10 hrs)

Normal Range

0-60

0-12

0-20

0-18

Marginal Range

61-70

13-15

21-25

19-22

High Range

71-86

16-17

26-30

23-26

Abnormal

87+

18+

31+

27+

Average Concentration Other Elements:

WATER LIMIT: 1,000 ppm on 0.100% (if equipment is available at lab)

The tail rotor gearbox has a self-contained gearbox without an oil filter. Normal wear

particles will continue to increase until the gearbox is drained, flushed and reserviced in

accordance with NAVAIR 01-260HCD-2-4.1. Water in the oil will cause either high iron

and copper or high iron, copper, magnesium and aluminum because of corrosion.

When high or abnormal wear metal readings are obtained, check the oil for water

content. If high or abnormal wear metals are detected and/or the water content of the

oil exceeds 1,000 (0.100%)*, the laboratory recommendation should be "flush gearbox,

reservice and perform serviceability check in accordance with NAVAIR 01-260HCD-2-

4.1. Submit oil sample after serviceability check and special oil sample after 10 flight

hours of operation for both wear metals and water content."

*Water content check dependent on special equipment availability.

High metal readings without exceeding 1000 ppm water content may result in a

laboratory recommendation for flushing or removal of the gearbox. A minimum of two

consecutive high readings is required prior to recommending flushing or gearbox

removal unless secondary indications (chips, unusual noise, etc.) are present. Inform

CFA when recommending flushing. CFA concurrence is required prior to

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

recommending gearbox removal.

A125