The document provides guidance on cleaning aircraft to prevent corrosion. It outlines three exterior cleaning methods - wet wash, dry wash, and polishing. It describes how to clean different areas of the aircraft like the wheel wells, engines, windows, and tires. It also discusses solvent cleaners, mechanical cleaning materials, recommended cleaning procedures, and post-cleaning procedures to inspect and lubricate the aircraft. Maintaining a clean aircraft is important for corrosion control and safety inspections.

1. Aircraft Cleaning
Author: Herbert Alpiger
THIS INTELLECTUAL WORK IS THE PROPERTY OF THE AUTHOR. In reference to KCTCS AP
& P 3.3.5 .This work may be distributed for educational purposes, provided that credit is given to
the author (by this page). All uses must be approved on a yearly basis by the author in writing. No
changes can be made to this material without written consent of the author.

2. ATE 102
Aircraft Cleaning and Corrosion and
Control
Part I
Aircraft Cleaning

3. Cleaning
The most important rule for corrosion control is to keep the
aircraft clean.
• Dirt & grease hold moisture in contact w/ the metal
surfaces
• A clean aircraft is easier to inspect for the first signs of
corrosion

4. Cleaning an aircraft and keeping it clean are extremely
important.
• A cracked landing gear fitting covered with mud and
grease may be easily overlooked.
• Dirt can hide cracks in the skin.
• Dust and grit cause hinge fittings to wear excessively.
• A film of dirt if left on the aircraft's outer surface,
reduces flying speed and adds extra weight.
• A coating of dirt and grease on moving parts makes a
sort of grinding compound that can cause excessive
wear.
• Salt water has a serious corroding effect on exposed
metal parts of the aircraft.

5. Exterior Cleaning
There are three methods of cleaning
the aircraft exterior:
(1) Wet wash,
(2) Dry wash
(3) Polishing.

6. Exterior Cleaning
Wet wash removes oil, grease, or carbon deposits
and most soils, with the exception of corrosion
and oxide films. The cleaning compounds used are
usually applied by spray or mop, after which high
pressure running water is used as a rinse. Either
alkaline or emulsion cleaners can be used in the
wet wash method.

7. Exterior Cleaning
Dry wash is used to remove airport film, dust,
and small accumulations of dirt and soil when
the use of liquids is neither desirable nor
practical. This method is not suitable for
removing heavy deposits of carbon, grease,
or oil, especially in the engine exhaust areas.
Dry wash materials are applied with spray,
mops, or cloths, and removed by dry
mopping or wiping with clean, dry cloths.

8. Exterior Cleaning
Polishing can be broken down into hand polishing
and mechanical polishing. The type and extent of
soiling and the final desired appearance determine
the cleaning method to be used.
Polishing restores the luster to painted and
unpainted surfaces of the airplane, and is usually
performed after the surfaces have been cleaned.
Polishing is also used to remove oxidation and
corrosion. Polishing materials are available in
various forms and degrees of abrasiveness.

9. Exterior Cleaning
The washing of aircraft should be performed
in the shade whenever possible as cleaning
compounds tend to streak the surface if
applied to hot metal, or permitted to dry on
the area.
Install covers over all openings where water
or cleaners might enter and cause damage
such as engine inlets & pitot tubes.

10. Various areas of aircraft, such as the sections housing radar and
the area forward of the cockpit that are finished with a dull
paint, should not be cleaned more than necessary and should
never be scrubbed with stiff brushes or coarse rags.
A soft sponge or
cheesecloth with a
minimum of manual
rubbing is advisable.

11. Wheel wells & the engine cowling usually have grease & oil deposits
which are more difficult to clean.
• Soak these areas w/ a 1:2 mixture of emulsion cleaner
• Scrub w/ a soft bristle brush
• Rinse w/ high-pressure water

12. Exterior Cleaning
Exhaust stains can be even more
difficult to remove.
• Apply a 1:2 mixture of emulsion
cleaner w/ varsol or kerosene.
• Scrub w/ a soft bristle brush
• Rinse w/ high-pressure water

13. Exterior Cleaning
Fayed surface – the metal that is covered in a lap joint.
• During cleaning take care to prevent corrosive cleaners
from seeping into the fayed surfaces.

14. Cleaning Aircraft Tires
Engine oil can damage AC tires & should be
removed.
• Remove any oil & grease by wiping w/ a rag
dampened w/ aliphatic naphtha
• Wash w/ a mild soap & water
• Dry w/ compressed air

15. Cleaning Windows
Transparent plastic such as acrylic are soft &
therefore easy to scratch. And the scratches will
impair the pilot’s vision.
• First flush w/ fresh water to wash away loose
particles to prevent scratching
• Remove any oil & grease by wiping w/ a soft
cloth dampened w/ aliphatic naphtha.
• Wash w/ a mild soap & water using your hand to
feel for abrasive particles
• Rinse w/ fresh water
• Dry w/ a chamois or absorbent cotton

16. Powerplant Cleaning
Grease & dirt on AC engines can:
• Interfere w/ cooling
• Hide cracks & other defects
• Hide fuel, oil, & exhaust leaks

17. Powerplant Cleaning
• Remove cowling
• Wash w/ an emulsion cleaner / kerosene
mixture
• Use a bristle brush to remove stubborn
deposits
• Dry w/compressed air
• Lubricate all bellcranks, control rods, &
other moving parts per the manufacturers
maintenance manuals

18. Propeller Cleaning
Propellers should be cleaned w/ a mild soap
& water, dried, and coated w/ a thin layer
of engine oil.

19. Preparation for Painting
When preparing a metal or fabric covered
surface for painting, remove every trace of
oil or grease.
• Wipe the surfaces down w/ dope thinner or
acetone

20. Exterior Cleaning
After cleaning, lubricate all grease fittings, hinges, etc., where
removal, contamination, or dilution of the grease is
suspected during washing of the aircraft.

21. Solvent Cleaners
AMT’s should review the Material Safety Data Sheet
(MSDS) available for any chemical, solvent or other
materials they may come in contact with during the
course of their maintenance activities
Particular attention should be paid to recommended
protective measures including gloves, respirators and
face shields.

22. Solvent Cleaners
Aliphatic naphtha – a petroleum product similar to
gasoline & kerosene used to clean grease from a
painted surface.
Aromatic naphtha – a derivative of coal tar not to
be used to clean aircraft parts or surfaces
because it is toxic & attacks acrylics & rubber
products.

23. Solvent Cleaners
• Dry Cleaning Solvent ( aka. Stoddard solvent) is the
most common cleaning solvent used on aircraft, due to
its low toxicity, minimal effect on paint, and relative
safety. It however leaves a slight residue upon
evaporation which must be removed because it may
interfere with the application of some final paint films.
• Methyl Ethyl Ketone (MEK) is also available as a
solvent cleaner for metal surfaces and paint stripper for
small areas.

24. Solvent Cleaners
Kerosene is mixed with solvent emulsion type cleaners
for softening heavy preservative coatings. It is also
used for general solvent cleaning. Kerosene generally
leaves an appreciable film on cleaned surfaces, which
may actually be corrosive and should be removed with
safety solvent, water emulsion cleaners, or detergent
mixtures.

25. Solvent Cleaners
Emulsion Cleaners
• a chemical cleaner which mixes w/ water or a petroleum
solvent to form an emulsion mixture which will separate if it is
allowed to stand.
• They are used in general aircraft cleaning. Solvent emulsions
are particularly useful in the removal of heavy deposits, such as
carbon, grease, oil, or tar. When used in accordance with
instructions, these solvent emulsions do not affect good paint
coatings or organic finishes.

26. Solvent Cleaners
• Do not use synthetic wiping cloths with flammable
agents. Because of the potential for static electrical
discharge igniting flammable fumes, wiping cloths
made of natural materials such as cotton should be
used.
• Agents should not be applied with atomizing spray
equipment. This is not only hazardous, but violates
environmental regulations in most areas.

27. Mechanical Cleaning Materials
Nonwoven abrasive pads (a common brand name
produced by the 3M company is Scotch-Brite™) are
useful for the removal of corrosion products and for
other light abrasive needs.

28. Mechanical Cleaning Materials
Powdered pumice can be used for cleaning corroded aluminum
surfaces.
Impregnated cotton wadding material is used for removal of
exhaust gas stains and polishing corroded aluminum surfaces

29. Mechanical Cleaning Materials
Aluminum metal polish is used to produce a high luster, long
lasting polish on unpainted aluminum clad surfaces.
It should not be used on anodized surfaces because it will
remove the oxide coat.

30. Mechanical Cleaning Materials
Aluminum wool and fine grit Aluminum oxide paper (300
grit or finer) are considered safe to use on most surfaces.
Avoid the use of carborundum (silicon carbide) papers,
particularly on aluminum or magnesium.
Emery paper or crocus cloth on aluminum or magnesium
can cause serious corrosion of the metal

31. Mechanical Cleaning Materials
Steam cleaning is not recommended for general use on
aircraft as it erodes paint, crazes plastic, debonds
adhesives, damages electrical insulation, and drives
lubrication out of bearings. It may however be used
effectively to remove corrosion causing microbial growth
from fuel tanks and for removing loosened paint and
chemical stripper from aircraft surfaces.

32. Cleaning Procedures
The following cleaning procedures are recommended:
• Remove/disconnect all electrical power;
• Ground aircraft;
• Aircraft wash personnel should wear protective gear (gloves, goggles,
aprons, etc.);
• Protect against water/cleaning compound intrusion (close doors,
openings, cover vents, pitot static openings, cover wheels, etc.);
• Mix cleaning solution to manufacturer's recommendation;
• Use spray not a stream of water during aircraft wash;
• Do not use abrasive cleaning pads; and
• Rinse aircraft with fresh water to remove all cleaning compounds.

33. Postcleaning Procedures
• Remove all covers, plugs and masking materials;
• Inspect and clear all drain holes;
• Inspect all known water trap areas for water accumulation and
proper drainage;
• Lubricate aircraft in accordance with applicable maintenance
manual; and
• Apply operational preservation.