Table 3-1. Lubricating Oils, Turbine Engine Aircraft (Cont)
3. TheC-54 aircraft models A and B, without the winterization kit installed, are designed to operate only from -
20 to 125 (-7to 52 ).
4. Formaingear box, use MIL-L-23699 above +30 (-1.1 ). MIL-L-23699 requires ASOAP sampling at 10 hour
intervals when used in Main Gear Box. Below +30 (-1.1 ) and in arctic operations, use NATO Standard 0-149.
This latter oil is supplied under NSN 9150-00-935-4090 (55 gal dr.) or NSN 9150-00-180-6278 (5 gal cn.).
Commercially available comparable oils are SATO-35 (Texaco). Turbo-35 (Exxon), Turbo-750 (Shell), and Turbo
TJ-37 (Exxon) oil. The above commercial oils are compatible and may be mixed with no restrictions. For
intermediate, tail rotor, and cargo hoist gear boxes, use MIL-L-23699 when operating above -40 (40 ). When
operating in arctic conditions (-40 , -40C or below), lubricating oil NATO Standard 0-149 or MIL-L-7808 must
be used. MIL-L-23699 is the principal lubricant to be used in all new or newly overhauled intermediate, tail rotor,
and cargo hoist gear boxes. If MIL-L-23699 is not available, lubricating oil NATO Standard 0-149 is to be used.
IMPORTANT: MIL-L-23699 and NATO Standard 0-149 lubricating oils are not compatible, and must not be mixed.
If conversion between these oils is required, drain and completely flush. Refer to appropriate -20 manual for