DG Flugzeugbau LS4 - 11.2 Repairs of composite structures, General

Maintenance Manual LS4
Issued: May 2011
Copyright DG Flugzeugbau GmbH - any copy or publishing prohibited
Manual valid with the up-to-date cover page only
11-2
11.2 Repairs of composite structures, General
Caution: You are only allowed to use the materials specified in section 10.
Use only genuine spare parts.
Warning: Major damage which is outside the scope of the list below should
only be repaired by a certified repair station rated for composite aircraft
structure work.
For all aircraft under EASA regulations the following applies: According to part
21, subpart M to accomplish major repairs an approved repair instruction is
required, see also TN LS-S-01 “Approved repair methods according to EU
Commission Regulation 1702/2003 part 21, subpart M”
Definition of minor damage:
a. All damage to paint and fillers.
b. Holes on the belly of the fuselage if the maximum diameter does not
exceed the following:
Forward fuselage 80 mm
Aft boom 40 mm
Cracks in the belly maximum length:
Forward fuselage 120 mm
Aft boom 80 mm
The blind glue joints of the fuselage boom should not be damaged.
c. Holes, cracks and blisters in the wings, tail, and control surfaces, not in
excess of the following dimensions:
Diameter
Length
Wings
100 mm
150 mm
Stabilizer
50 mm
80 mm
Elevator
50 mm
80 mm
Aileron
50 mm
80 mm
Rudder
50 mm
80 mm
The parts must not be damaged in the spar area.
Caution: The stabilizer is a load carrying structure without spar. Damage in the
region 600 mm (23.6 in) from the centerline must not be repaired.
d. Replacement of bent fittings.
Caution: Damaged fittings should not be repaired but must be replaced.
Note: Special hints for handling FRP repairs are found in the Petite Plane Patch
Primer (Author U. Hänle).