Hard Time

File: 082696_d50030_051.txt
Page: 051
Total Pages: 101
10. Will using JET A-i which does not normally Contain the corrosion inhibL-
tor cause wear in fuel pumps and injectors of diesel engines?

   Answer:   &o.   Testing to date has shown the presence of corrosion
             inhibitors does not improve the "lubricity" of JET A-i or JP-5
             when used in diesel fuel engines.   The lubrication qualities of
             JP-5 or JP-8 when used in aircraft fuel control systems are
             significantly different than those qualities when used in
             diesel fuel injector/pump environments.   Moreover, the lubrica-
             tion requirements for diesel fuel injectors and pumps has yet
             to be defined.

ii. what causes growth of microbiological organisms (i.e., bugs) in fuel?

   Answer:   Microbiological organisms grow in fuels when separated water is
             present.   They will not grow in a water-free environment. The
             microbiological organisms start to form at the fuel-water
             interface and subsequently develop strands/fibers and/or "mats"
             into the fuel or produce a slime on the interior surfaces of
             the tank.   Moderate to warm ambient temperatures will acce-
             lerate the growth and proliferation of these micro-organisms.

12. Will microbiological organisms grow in both JET A-I and diesel fuels?

   Answer:   Yes.  Microbiological organisms will however grow more rapidly
             in diesel fuel than JET A-i as (1) diesel fuel tends to entrain
             more water than JET A-i and has poorer water separation quali-
             ties, and (2) diesel fuel contains higher amounts of normal
             paraffin-type hydrocarbons than JET A-i which are more favored
             as a nutrient by the various micro-organisms.

13. what additives should be used for controlling microbiological growth
(i.e., bugs) in fuel?

   Answer:   There are three (3) additives currently in the supply system
             which prevent/control the formation of microbiological growth
             in water bottoms of fuel tanks/cells.   Two of the additives
             are currently specified in JP-4/JP-5/JP-8 aviation turbine
             fuels whereas the other is recommended for use in diesel fuel
             as a means to enhance its storage stability.

             The two additives for aviation turbine fuel are called "Fuel
             System Icing Inhibitor1' and are described by both MIL-I-27686
             and MIL-I-85470.   The chemical ingredient in each of these is
             Ethylene Glycol Monomethyl Ether (ECME) and Diethylene Clycol
             Monomethyl Ether (DIECME), respectively.   The reco=ended
             treatment level for each in either turbine or diesel fuel is
             0.15% vol.


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