AIRCRAFT MAINTENANCE MANUAL
DFE-AMM-AR1
Rev. 1 – 07/24/2014
11-6
11.3. INSTRUCTIONS FOR AUTHORIZED MAINTENANCE, REPAIR OR ALTERATIONS
11.3.1. SMALL DAMAGE
Small damage is a deterioration of corrosion resistance. At repair the situation is made more
difficult by the fact that the substrate for repair coats is not a compact surface of basic material
but mostly all coats of surface protection (after grinding), of which not all are suitable for (in
ageing stage) for good adhesion of paint coats. Therefore we recommend carrying out such
repairs by a verified system.
Before repairing it is necessary to differentiate the type of the existing top coat, single coat
and two-coat (with the top coat). For repair it is necessary to follow the used type of color.
It is suitable to choose the delimited area (e.g. connection of sheets, wing edge) for the
scope of the place which is being repaired transition is then better blended. In the case that it is
not possible to choose the area in this way, it is necessary to take into consideration the higher
difficulty of the procedure as for the uniformity of shade and elaboration of coat transition
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Tools needed: abrasive-coated paper
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Parts needed: materials for primer and for top coat
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Type of maintenance: Line
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Level of Certification needed:
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Repairman (LS-M) or Mechanic (A&P) – both with the minimum level of certification to
perform heavy maintenance of SLSA in the U.S.
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FAA approved Part 145 Repair station
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Instructions:
1 – Grinding:
For good adhesion of the repair coats it is necessary to carry out grinding of the old paint
coat at least up to such depth as the depth of damage. With two-coat type of the top coat it is
necessary to add at least 50 mm (2 in) for the run-out of the top coat. Grinding can be started
with abrasive having grain size of max. 160 and to finish with grain size of 400. It is made by
the grinding equipment with the suction from the area of grinding or by manual grinding under
water.
Anodized coat must not be destroyed by grinding on the Al-alloy sheet.