c. Tube Method. (See appendix C, figure 5)
(1) Procedure is normally used in taking an aeronautical oil sample, but may be used for
other equipment.
(2) A plastic tube for sampling aeronautical equipment oil is preferred. The tube is used
through the oil filler neck or dipstick hole. Insert the tube into the reservoir. Be careful not to let
the tube touch bottom. Allow the tube to fill with oil. Place a finger over the tip of the tube and
withdraw it from the reservoir. The tube will be partially filled with oil. Insert the tube into the
sample bottle. Release the oil by removing your finger from the top of the tube. Repeat until the
bottle is filled within 1/2 inch of the top of the 5/8 ounce (5 dram) glass sample bottle.
NOTE: Replenish the fluid drained from the component with clean fluid.
(3) Enter the aircraft type/model/serial number, operating hours on the component,
component serial number/type/model, type and grade of lubricant used, and date and time sample
taken on the label of your oil sample bottle. Complete DD Form 2026 or ULLS DA Form 5991-
E. Place the sample and the form in a plastic bag and send to the laboratory by the fastest means
available; e.g., First Class mail or courier. Certain aircraft components require grease sampling
(identified in appendix A). Grease samples will be submitted ONLY in the 3 ounce
nonaeronautical plastic sampling bottle. To obtain grease samples, adhere to the individual
aircraft technical manuals.
d. Drain Method. Use this method if a sampling valve is not installed or the tube method is
not practicable. (See appendix C, figure 6)
(1) Obtain a bottle, a label, a DD Form 2026 or DA Form 5991-E, and a quart size waste
oil container.
NOTE: A quart size container, such as a coffee can, can be fitted with a locally fabricated wire
bracket designed to hold the sample bottle at the top of the can. This will allow the sample to be
taken with one hand and will free the other hand to replace the drain plug.
(2) Open the sample bottle. Place the bottle cap on a clean surface with the open end up to
avoid contaminating the inside of the cap.
(3) With the container underneath the drain point, open the drain plug and allow the initial
stream of oil to flow into the quart can. This will eliminate obtaining oil that has been trapped at
the drain port and may not be representative of the oil normally flowing through the component.
(See appendix C, figure 6A)
(4) Allow about one pint of oil to drain into the container to obtain oil representative of
the system. Allow the oil to drain into the sample bottle to within inch of top. CAUTION:
The oil sample may easily be contaminated with sludge or water if approximately one pint of oil
is not drained prior to sampling. (See appendix C, figure 6B)
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