As a Petroleum Laboratory NCO, you play an important role in evaluating the quality surveillance procedures
at aviation unit refueling facilities. You must have a thorough base of knowledge of contamination sources,
sampling procedures, sample testing, and SOPs in order to make the right decisions.
PART A - IDENTIFY POTENTIAL SOURCES OF CONTAMINATION FOR
Contamination with other products. This type of contamination is usually a result of inadvertent
mixing with other petroleum products during transportation and storage. Contamination is detected by
Contamination with Water, Solids, and Microbiological Growth. These types of
contamination can usually be detected visually since they are not mixable with the fuel. A detailed list of the
frequently encountered types including appearance, characteristics, and effects on aircraft performance can
be found in Table X, MIL-HDBK-200.
Water. Water in fuel may be either fresh or salt and may be present either as dissolved or free water.
Dissolved water is that which has been absorbed by the fuel and is not visible. Free water may be in the
form of a cloud, emulsion, droplets, or in large amounts in the bottom of a tank or container. Free water
can cause icing in an aircraft fuel system, malfunctioning of fuel quantity probes, and corrosion of fuel
system components. Saltwater will promote corrosion much more rapidly than fresh water.
Sediment. Sediment appears as dust, flakes, or granular or fibrous materials. Total sediment includes
both organic and inorganic materials. Presence of appreciable quantities of fibrous materials is
indicative of filter element breakdown due to a ruptured element or mechanical disintegration of the filter
element in the fuel system. Sediment or solid contamination will be either coarse or fine. Coarse
sediment is ordinarily 10 microns in size or larger. It easily settles out of the fuel or can be removed by
adequate filtration. Fine sediment is smaller than 10 microns and to a limited degree can be removed by
settling, filtration, or centrifuging.
Microbiological growth. Microbiological growth consists of living organisms that grow at the fuel water
interface. These organisms include protozoa, fungus, and bacteria, all of which can cause problems
associated with microbiological contamination of aviation turbine fuels. Microbiological growth is
generally found wherever pockets of water exist in fuel tanks. It has a brown, black, or gray color, and a
stringy, fibrous-like appearance. FSII additive at 15 percent by volume is effective in controlling
microbial contamination. If water is absent, microbiological growth cannot occur.
PART B - EVALUATE QS PROCEDURES AT AN AVIATION UNIT REFUELING
Evaluate the unit's operational SOP to verify that procedures for maintaining the quality of petroleum
product are established and make recommendations, when required.
- Aviation fuel must
be kept free
of solid and water contamination before using.
At a fuel system
supply point, filter/separators should be installed.
- Aviation fuel must be passed through an approved filter/separator before it is delivered to any
- The fuel is again passed through a qualified filter/separator before being dispensed to any aircraft.
Monitor sampling and gaging procedures.
- Verify annotation in sample log box.
- Inspect sample submission procedures.
Inspect logbooks/records to verify that required quality surveillance procedures are being performed.
- Inspect product rotation history.
- Review completed DA Form 2077.
- Review DA Form 4702-R.
Provide assistance in the investigation of aircraft crashes.
of aviation fuels for possible contamination/deterioration.