AIRCRAFT
DA 42 NG AMM
Standard
Practices/Structures
Doc # 7.02.15
Rev. 4
51-20-00
Page 201
15 Mar 2018
Maintenance Practices
1. General
These Maintenance Practices tell you about composite repair processes and how to repair Class 2,
3 and 4 damage to the composite structure. Refer to Section 51-10 for data about damage
classification. Class 1 damage may only be repaired in accordance with a repair scheme approved by
the manufacturer. All repairs must only be carried out by approved persons.
You must only use the materials approved by the manufacturer when repairing the airplane. Refer to
Section 51-30 for data about approved materials.
Inspect the damaged area(s). Look specially at the adjacent structure. Damage can go a long way
under the surface of a composite. Use the techniques given in Section 51-10.
You must take care to do the repair correctly. The outer shell of a composite structure is stressed.
Failure of the structure can cause an accident.
2. Resin
You must use the correct quantity of mixed resin for the repair. Weigh all the cloth patches that you
will use for the repair. The ratio for glass cloth to resin mix is 100 : 70. For example, 100 grams of dry
cloth require 70 grams of mixed resin. The ratio for carbon cloth to mixed resin is 100 : 85. For
example, 100 grams of dry carbon cloth requires 85 grams of mixed resin.
Measure the quantities of resin and hardener accurately (± 0.5% by weight). Mix the resin and
hardener thoroughly before laminating, or adding fillers or other additives.
Always use clean containers for mixing resin and only mix as much resin as you can use within its
‘working life’.
When using large quantities of resin put it shallow containers. This will increase the ratio surface area
to volume which will reduce the risk of an exothermic reaction.
Two types of structural resin systems are in use, further designated as L285 and RIM 935 (refer to
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Section 51-30 for detailed data). The part must be repaired with the same resin system as used during
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manufacturing of the part. The resin system is clearly defined by a distinguished part number and is
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stated on the identification label of the part. The resin system can also be specially defined for specific
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parts (e.g. cowlings). In case of doubt, contact Diamond Aircraft for assistance.
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Summary of Contents for DA 42 NG
Page 933: ...AIRCRAFT DA 42 NG AMM Fuel Doc 7 02 15 Rev 4 28 TITLE Page 1 15 Mar 2018 CHAPTER 28 FUEL ...
Page 1459: ...AIRCRAFT DA 42 NG AMM Lights Doc 7 02 15 Rev 4 33 TITLE Page 1 15 Mar 2018 CHAPTER 33 LIGHTS ...
Page 1711: ...AIRCRAFT DA 42 NG AMM Doors Doc 7 02 15 Rev 4 52 TITLE Page 1 15 Mar 2018 CHAPTER 52 DOORS ...
Page 1853: ...AIRCRAFT DA 42 NG AMM Wings Doc 7 02 15 Rev 4 57 TITLE Page 1 15 Mar 2018 CHAPTER 57 WINGS ...
Page 2071: ...AIRCRAFT DA 42 NG AMM Engine Doc 7 02 15 Rev 4 72 TITLE Page 1 15 Mar 2018 CHAPTER 72 ENGINE ...
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