Diamond Aircraft DV 20 E 2022, Airplane Maintenance Manual

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AIRCRAFT
Standard Practices and
Structures
DV 20 E AMM
Page 2
15 Mar 2022
51-10-00
Doc # 4.02.25
Rev. 2
3. Types of Damage
There are two basic types of hidden failure in composite structures:
)
Disbonding.
)
Delamination.
Disbonding is the failure of a bond between two components. For example between the fuselage skin
and a fuselage frame. Or between a composite component and a metal component. Or between a
composite skin and a sandwich core material.
Delamination is the failure of the bond between layers of glass/carbon cloth in a component.
There are also two main types of cracks:
)
Micro cracks which occur in the surface of the resin.
)
Major cracks with broken fibers. Major cracks do not occur with normal flight loads or normal
landing loads. You must repair major cracks.
4. Inspection Techniques
A. Examine Visually
Use this method to find all types of damage to composites. Use a bright light to examine visually
the inside of a component. GFRP must be green or brown. If the GFRP has white areas, then it
may be damaged. Look specially at areas where components bond to the GFRP.
CFRP must be black or black/brown. If the CFRP has white areas, then it may be damaged. Look
specially at areas where components bond to the CFRP.
Look carefully at the outer surface of a component. If the paint has cracks or bubbles, then the
composite may be damaged. Refer to Paragraph 5 in this Section.
Also look for dents. Look specially in areas where stones can hit the airplane below the fuselage
and the wings. Look specially in the areas of the walkways.