01 March 2005
Mill Scale - The heavy oxide layer formed during hot
fabrication or heat treatment of metals. The term is most
Impingement Attack - A form of erosion corrosion that
frequently applied to the scale of mixed iron oxides on
is associated with turbulent flow of a liquid, as at the
iron and steel.
entrance of a condenser tube or around bends in a pipe
line. Air bubbles can accelerate impingement attack.
Minimum Failure Free Lifetime (MFL) - The minimum
period of time that an avionics system, subsystem,
Inhibitor - A chemical substance or mixture which,
module or component performs satisfactorily without
when added in small amounts to a solution, markedly
Mottling - Appearance of spotting or blotches of different
Inorganic Coating - A coating composed of matter
color or shades of coloring.
other than of plant or mineral origin (e.g. electroplate,
chemical conversion, anodize, phosphate or oxide).
Integral Fuel Tank - A load carrying structure of an
aircraft that is completely sealed to provide fuel
of nitrogen and oxygen. Present in many industrial
containment. It may exist as a cavity in a wing and/or the
Noble Metal - A metal usually found as uncombined
Ion - An electrically charged atom, group of atoms, or
metal in nature, characterized by excellent corrosion
molecule. The sign of the charge is positive in the case
resistance and high cost. Also called precious metals.
of cations and negative in the case of anions.
Platinum, gold, and silver are noble metals.
Noncritical Avionics Components - Any avionic
component that is not critical to the function of the
Lacquer - A paint that contains a synthetic resin and
aircraft, such as tubes, tube sockets, resistors,
forms a film after solvent loss. The film is susceptible to
mechanical devices, knobs, various macroelectronic
attack by the same or similar solvents used in the
components and hardware.
Non-Destructive Inspection - An inspection method
Local Cell - A cell in which the driving force is due to a
used to check the soundness of a material or a part
difference in potential between areas on a metal or alloy
without impairing or destroying the serviceability of the
surface immersed in an electrolyte. The potential
part. Examples are ultrasound, x-ray, and liquid
difference may be due to inclusions, lack of homogeneity,
or varying concentration of the solution with respect to
oxygen or metal ions.
Orange Peel - A surface bumpiness or waviness that
resembles the skin of an orange. Orange peel is often
Malfunction - Failure to function correctly, especially a
caused by poor leveling and is a common defect in both
failure causing a flight safety situation, a mission abort,
spray and roll applied painted surfaces.
or a failure to accomplish mission.
Organic Coating - A coating composed of matter
Matte Surface - A surface with a dull finish, as in the
derived from living organisms or carbon containing
case of an etched or sandblasted surface.
compounds (e.g. paint, lacquer, plastic, grease,
Microbes - Microscopic living plants or organisms,
Outgassing - Emission of a gas during the cure or
such as germs or bacteria.
decomposition of organic material, usually increased in
rate by higher temperatures.
Mil - One thousandth of an inch.