AIRCRAFT MAINTENANCE MANUAL
DFE-AMM-AR1
Rev. 1 – 07/24/2014
10-6
10.3.2. FIBERGLASS PARTS REPAIRS
10.3.2.1. Damage classification
Any damage of parts from reinforces plastics with epoxy matrix leads to increased
saturation of the matrix with humidity and subsequently to loss of properties. Therefore we
recommend carrying out their repair as soon as possible after the damage has occurred.
Two kinds of parts are made from these materials in the airplane:
•
design appearance, non load-bearing parts (fairings)
According to the damage size we can divide repairs into:
•
Small damage: surface defects, not affecting the stiffeners
•
Medium damage: small cracks in fairings (excluding any defects to landing gear legs)
•
Big damage: Major “Not repairable” structural, load-bearing parts (landing gear legs)
We recommend carrying out repairs by means of epoxy materials and glass stiffeners
10.3.2.2. General
Epoxy mixtures are prepared in a given mass ratio by means of weighing (accuracy of scales 1g).
10.3.2.2. Parts of external appearance
10.3.2.2.1.Small Damage
•
Tools needed: sand paper, scissors,
•
Parts needed: epoxy resin, drills, fiberglass cloth , degreasing agent
•
Type of maintenance: Line
•
Level of Certification needed:
-
Repairman (LS-M) or Mechanic (A&P) – both with the minimum level of certification to
perform heavy maintenance of SLSA in the U.S.
-
FAA approved Part 145 Repair station
•
Instructions:
Repair of damage just by application of mastic and by varnish repair.
Preparatory grinding
For a good adhesion of repair layers it is necessary to carry out surface grinding at the
utmost up to the depth of contact with the stiffener (do not damage). It is necessary to do
surface grinding with overrun of 50 mm from the damage location smoothly to the top layer. It
is suitable to do grinding with grain size of 160. Dry grinding equipment with suction from the
grinding area is used. Al2O3 (fused corundum) can be used as grinding material.
Dust removing
It is made by wiping with clean and dry brush or by a vacuum cleaner.
