TAIL ROTOR GEARBOX (Cont) - TM-38-301-30193

NAVAIR 17-15-50.3

TM 38-301-3

T.O. 33-1-37-3

CGTO 33-1-37-3

SH-60B, SH-60F, HH-60H, MH-60S, MH-60R (Cont.)

TAIL ROTOR GEARBOX

Monel safety wire is used to safety the connecting bolt between connecting

link and fitting inside pitch change shaft assembly. This link and fitting,

together with duplex ball bearing set, provide the connection between tail

rotor servo and pitch change shaft that allows shaft to rotate while

simultaneously moving axially with servo inputs. Monel is approximately 60-

65 percent nickel and 30 percent copper. Because this safety wire is not

normally subject to wear and is not exposed to significant amounts of oil,

contribution to NOAP is questionable.

Silicon is not a critical wear metal in the tail rotor gearbox, but should be

monitored due to the potential for abrasion if levels grow too high. The

probable sources of silicon are contamination from sand or from leakage of

silicon base grease through the pitch change shaft sear. Oil change shall be

recommended for verified silicon level over 100 ppm.

A171