1-20. Laboratory Operating Procedures. The following scenario pertains to the AOAP Mobile Laboratory processing
selected aeronautical and nonaeronautical oil samples in a tactical environment. Further, it is not to be conceived as the
"ONLY" way of performing specified AOAP analysis.
The process begins with the soldier in the field who takes an oil sample and fills in applicable data elements on
a DD Form 2026, Oil Analysis Request. The completion of this form, which accompanies the sample to the laboratory, is
critical to the success of the analysis, since all data relating to the component from which the oil was taken is entered off
this form. Component serial number, hours since last oil change, and hours since last overhaul are examples of data
required by the evaluator for accurate assessment of component wear or changes to the lubricating oil's physical
On receipt of the oil sample at the AOAP Mobile Laboratory, the components sample's header information is
entered in the AOAP Mobile Laboratory's Standard Data System (SDS) computer. The SDS assigns an index number to
each serial numbered component. The index number is where the current and/or historical analysis information is stored
in the computer, which is retreived by entering components serial numbers.
The oil sample at this time can have spectrometric or physical property analysis performed, since the
aeronautical oil samples require only spectrometric analysis to be performed, except for selected AH- 1's components
requiring ferro graphic analysis. Thus, for discussion purposes ONLY, oil analysis process will begin with spectrometric
analysis test, which is performed on all components enrolled in AOAP.
The oil sample is analyzed for up to 15 wear metals on the spectrometer. The spectrometer is interfaced with a
Wang MICROVP-2 computer system. This system has been loaded with AOAP wear metal guidelines for components
enrolled in AOAP. If element(s) exceed(s) the specified spectrometric guidelines for that component, then the evaluator
reviews analysis data and makes a recommendation to the owning unit. These recommendations can range from an oil
and filter change to the removal of the component from service. To ensure the proper operation of the spectrometer, the
operator performs daily standardization checks on the instrument before each day's start up. However, if the
spectrometer does not pass these prescribed daily standardization checks, then a complete standardization is performed.
Additionally, periodic standardization checks are made throughout the day. At a minimum, these checks are made when
switching from analysis of aeronautical to nonaeronautical samples (and vice versa), or whenever the spectrometer has
not been operated for 30 minutes or more.
Physical property testing is performed on nonaeronautical engine and transmission oil samples to determine the
on-condition of the oil in these components.
The Crackle Test is performed utilizing a hot plate set at 300 to 350 degrees Centigrade (150-175 degrees
Fahrenheit) surface temperature to ascertain presence of water contamination. This test is accomplished by placing one
drop of oil on the surface of the hot plate. A positive test is indicated by an audible crackling and spattering of the oil.
The determination of the viscosity of used oils is performed using a Direct Readout Viscometer. The viscosity
reading is obtained by immersing the viscometer's vibrating sphere into the nonaeronautical oil sample. If the viscosity
reading of the used oil sample obtained is below the prescribed lower criteria guidelines, then additional testing is
conducted to determine if fuel dilution, contamination, or lubricant degradation has occurred. Additionally, if the viscosity
readings obtained are above the upper criteria, then the evaluator may recommend an oil and oil filter change.