PD9B01M0 1ST ISSUE 1/07/2019 18
2.4 100 hour/annual check list
After this first 25 hours maintenance, all other scheduled maintenances actions follow the 100
hours intervals. The check list for the maintenance actions are listed in the ANNEX A
that clearly
reports the prescribed actions subdivided in:
✓
I:
Inspections actions;
✓
M:
Maintenance actions;
✓
R:
Replacements actions;
✓
C:
On condition (check and replace if necessary) actions.
For each of the prescribed actions and for each functional group, the OS point out when and what
to do, referring to detailed sheets that are part of the document as well.
2.5 Corrosion prevention
Keeping the aircraft in cleaned conditions and removing any collection of corrosive agents such as
oil, grease, dregs and other foreign matter it is of crucial importance for the integrity of the
structure. To avoid damage to the surface finishing, do not use polishing detergents. Composite
materials or polymer related parts are subjected to degradation if not properly protected from
environmental factors. Any undesirable change in properties or appearance of a composite
material can be considered such as a form of degradation.
One of the first indicators of degradation is the change in the surface appearance or gloss,
followed by a change in the color of the surface resin. Wood parts are not strictly affected by
corrosion but may be affected by excess and prolonged exposition to humid environment hot and
cold both.
In order to avoid premature degradation of wood characteristics, the aircraft must be stored within
the prescribed limitations, see POH. Original or equivalent corrosion/degradation prevention must
be re-applied after any alteration or repair.
If any trace of corrosion is detected it must be removed as soon as possible and immediately
treated with the aim to prevent dangerous degradation of the affected component and related parts
that could compromise the safety of overall flying operations. The general guidelines to prevent
corrosion/degradation of various materials are:
For steel parts
: with the exception of highly stressed components or stainless steel, it is possible
to use abrasives, power brushes, steel brushes if operated manually and steel wool. Removing
corrosion by products from highly stressed steel components (main gear steel spring) requires
particular care.
For aluminum parts:
treatment consists in mechanically removing as much as possible corrosion
by products, applying corrosion inhibitor and replacing original finish. Steel wool, emery or steel
brushes (unless stainless steel) along with other highly abrasive material should not be used since
steel or emery particles become embedded in the softer material causing corrosion.
After cleaning surface corrosion, parts must be treated with an anti-corrosion finish prepared as
follows:
✓
Applying corrosion inhibitor;
✓
Accurate brushing with a sturdy fiber brush will rid most of the corrosion and insure that the
anti-corrosion agent will penetrate completely in the cracks;
✓
Leave the corrosion inhibitor on the part for at least five minutes and then remove excess
with water or a damp cloth;
✓
Apply protective finish the same day in which treatment begins.
For composite parts
: composite material or polymeric material degradation treatment is
particularly difficult and requires special skill. If any composite or polymeric material degradation is
