Dip Tube Sampling.

NAVAIR 17-15-50.1

TM 38-301-1

T.O. 33-1-37-1

CGTO 33-1-37-1

NOTE

Special sampling is not required for maintenance performed on oil pressure or quantity

indicating systems where it is determined that only the instrument system components

are faulty and where repair, replacement and/or failure of these components will not

cause damage to oil wetted components or cause wear-metal particles, foreign material

and/or instrument system fluids to be introduced into the oil system.

(e) After flight test following installation of new, overhauled, or repaired aircraft engines.

(f) At completion of a test cell run. If unit is operated on oil previously used in the test cell

system, a sample is required both prior to and at the completion of the test cell run.

(g) Whenever excessive vibration or a chip light indication is experienced on an aircraft engine

or component during flight, ground or test run.

(h) Immediately following all aircraft incidents involving failure of internal enclosed lubricated

parts or unplanned/unexpected shutdown affecting operation of internal enclosed lubricated parts.

(i) Immediately following all aircraft accidents regardless of cause and resulting damage.

These samples will be taken by any means possible to obtain a representative sample.

(j) Prior to overseas deployment or redeployment of any equipment already being monitored by

oil analysis. Samples should be taken far enough in advance to assure receipt of analysis prior to unit deployment

or redeployment. A sample prior to departure is not required if: (1) the aircraft is on routine sampling; and (2) oil

analysis records will accompany the aircraft; and (3) the normal sampling interval can be maintained due to the

availability of an oil analysis facility at the destination.

(3) Additional Special Samples. Special samples taken from equipment not enrolled in a service oil

analysis program may be submitted to a JOAP laboratory. No advice is provided for samples that do not have

limits provided to JOAP by the cognizant engineering activity.

How to Take Samples. There are three basic techniques for taking a sample; dip tube,

drain/valve, and pump. Detailed sampling procedures for specific equipment are established in applicable service

documentation governing the use and operation of such equipment.

(1)

Dip Tube Sampling.

(a)

Remove the filler cap/dip stick from the tank and open the sample bottle.

(b) Using a sampling tube of the correct length, grasp the tube at one end and lower it into the

tank through the filler neck (see figure 3-3, Views A and B). For units using the new sampling kit with the plastic

bottle, insert one end of the dip tube into the opening on the cap of the plastic bottle. Insert the other end into the

oil reservoir. Squeeze and release the bottle. After the sample is obtained, remove the tube and close the lid.

WARNING

Do not use mouth suction to fill the sampling tube. Many fluids are highly toxic and may

cause paralysis and/or death.

finger. Withdraw the tube and drain the trapped fluid into the sample bottle (see figure 3-3, Views C and D).

Repeat this operation until the bottle has been filled to approximately 1/2 inch from the top.

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