AIRCRAFT MAINTENANCE MANUAL
DFE-AMM-AR1
Rev. 1 – 07/24/2014
10-10
Putting layers
After preparing lamination mixture (for recommendation of material see the Tab. on page
10-4), it is applied to the place of repair by means of rigid brush. The first stiffener is laid into the
deposit and it is again saturated by brush. Another layer of stiffener is laid and saturated. When
putting the last layer it is necessary to pay attention to a proper saturation and compression of
stiffeners so that they cannot “come up” to the surface and subsequent useless damage at final
grinding. For better saturation of the surface by resin and securing against curtaining it is
possible to put PE or PP transparent foil across the surface. When applied properly, the layer is
without bubbles. Repair thickness should exceed surrounding surface in this phase by about
0.5 to 1 mm (0.02 – 0.04 in) for finishing.
Grinding
Carry out grinding and eventually apply mastic on the surface after setting, eventually
tearing off the folia (see small damage). It is suitable to begin grinding by abrasive with grain
size of 160 and finish by grain size of at least 400. Dry grinding equipment is used with suction
from the grinding area. Al2O3 can be used as grinding material. It is important not to diminish
basic material of the part at grinding.
Especially in case of Carbon/Kevlar stiffener in the basic part there must not be any grinding through up to
the stiffener (complication -see the note about preparatory grinding).
Finishing
See Section 11 – Painting and Coatings.
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Task proper accomplishment check: Visual check.
10.3.2.2.3.
Big Damage
At such damage we recommend to replace the affected part.
10.3.2.3. Structural Parts
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Instructions:
With these parts we do not recommend to do other repairs than small damage repairs as
specified on Paragraph 10.6.2.2.1. In case of the other damage we recommend to contact
manufacturer.
When repairing, it is necessary to carefully pay attention not to damage the stiffeners!
Cracks, permanent deformations and breaks are the most relevant type of damage.
Prior to undertaking the repair, clean the area to be repaired thoroughly, with soap and
water. Remove any paint by wet or dry sanding. Superficial scars, scratches, surface abrasions,
or erosion can generally be repaired by applying one or more coats of epoxy resin. The number
of coats required (2 generally) depends upon the type of resin and severity of damage. The
layers should have an overlap of 1.5-2 in (30-50 mm). After the resin has cured, sand off any
excess and prepare the area for priming and painting.
