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## Repairs to a Pressurized Area 

The skin of aircraft that are pressurized during flight is highly stressed. The pressurization cycles apply loads to the skin, and the repairs to this type of structure requires more rivets than a repair to a nonpressurized skin. [Figure 4-182] 

1. Remove the damaged skin section. 

2. Radius all corners to 0.5-inch. 

3. Fabricate a doubler of the same type of material as, but of one size greater thickness than, the skin. The size of the doubler depends on the number of rows, edge distance, and rivets spacing. 

4. Fabricate an insert of the same material and same thickness as the damaged skin. The skin to insert clearance is typically 0.015-inch to 0.035-inch. 

5. Drill the holes through the doubler, insertion, and original skin. 

6. Spread a thin layer of sealant on the doubler and secure the doubler to the skin with Clecos. 

7. Use the same type of fastener as in the surrounding area, and install the doubler to the skin and the insertion to the doubler. Dip all fasteners in the sealant before installation. 

