MIL-PRF-23699 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base, Nato Code Numbers: O-152, O-154, O-156, And O-167This specification covers four classes of gas turbine engine lubricating oils, primarily used for aircraft engines, which have a nominal viscosity of 5 centistokes at 100 ┬░C and which are typically made with neopentyl polyol ester base stocks. This oil is identified by NATO Code Numbers O-152, O-154, O-156, and O-167.

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MIL-PRF-23699G

4.4.19 Conformance inspection testing methods. The following information is in support of

the conformance testing required in table III.

4.4.19.1 Bearing deposits conformance testing. The bearing deposit test (see table II) shall

be performed on the first three full-scale production lots of each qualified lubricating oil supplied

to the procuring activity.

4.4.19.2 Ryder gear load carrying capacity conformance testing. The Ryder Gear test (see

table II) shall be performed on the first ten full-scale production lots of each newly qualified

Class C/I and EE lubricating oil supplied to the procuring activity. Additional requirements for

performing the Ryder Gear test on subsequent production batches may be specified in the

procurement contracts. Additional load carrying test methods may be deemed suitable for

qualification of management of change issues at the discretion of the qualifying activity. The

products shall meet the conformance test requirements as stated in 4.4.19.2.1 and 4.4.19.2.2.

4.4.19.2.1 Class C/I products criteria. Class C/I products shall meet one of the following

criteria:

a. greater than or equal to 112 percent of the Herco A reference fluid value if measured by

two determinations.

b. greater than or equal to 106 percent of the Herco A reference fluid value if measured by

four determinations.

c. greater than or equal to 102 percent of the Herco A reference fluid value if measured by

six determinations.

4.4.19.2.2 Class EE products criteria. Class EE products shall meet the following criteria:

a. greater than or equal to 110 percent of the Herco A reference fluid value as measured by

six determinations.

4.4.19.3 Bearing corrosion conformance inspection procedures. The bearing corrosion test

shall be performed on all production batches of Class C/I lubricant supplied, except as noted in

4.4.19.3.1. Each production batch of the oil shall successfully pass one series of bearing

corrosion tests (see table II) on the new oil. This series shall consist of nine candidate specimens

and one each of the pass and fail reference oils (see 4.4.16).

4.4.19.3.1 Corrosion additive. Confirmation of the presence of the corrosion additive may

be conducted using a quantitative laboratory analytical method of analysis approved by the

qualifying activity. Confirmation of the specified additive package by such approved methods

may be substituted for a bearing corrosion test to satisfy the quality conformance test

requirement.