Aircraft Composite Repair Process

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What is the primary reason for thermal variations in the repair area?

Material type (correct)

Underlying structure

Material thickness

Technician's experience

Why is it important to know the structural composition of the area to be repaired?

To choose the correct repair technique (correct)

To determine the technician's skill level

To conduct a thermal survey

To identify possible hot and cold areas

What happens if the temperature of the thermocouple varies more than 10 degrees from average during the thermal survey?

Remove the thermocouple

Replace the material patch

Increase heating blanket temperature

Add more insulation (correct)

Why do stringer and rib areas in the repair zone have lower temperatures than the middle of the patch?

They act as a heat sink Signup and view all the answers

What can be done to address heat sink problems in the repair area?

Add more insulation Signup and view all the answers

How does the thickness of skin sections affect heating during repairs?

Thick skins easily overheat Signup and view all the answers

What is the main disadvantage of using the described press method?

It only applies pressure in one direction. Signup and view all the answers

What is the typical range of rapid forming times mentioned in the text?

10 minutes - 2 hours Signup and view all the answers

What is a thermocouple used for?

To measure temperatures Signup and view all the answers

How is an electric current produced in a thermocouple?

By joining dissimilar metals Signup and view all the answers

Which type of insulation is recommended for higher cure temperatures when using TC wire?

Kapton-insulated wire Signup and view all the answers

Why is thermocouple placement important in repair processes?

To ensure proper cure temperatures Signup and view all the answers

What is one of the drawbacks of using a scarf joint for bonded repairs?

A large quantity of material must be removed to maintain a small taper angle. Signup and view all the answers

Why is it important to have better trained personnel for bonded repairs compared to bolted repairs?

Bonded repairs involve more complex procedures like laying up replacement plies accurately. Signup and view all the answers

What can happen if replacement plies are not cured in an autoclave during a repair?

The strength of the repair joint may be significantly reduced. Signup and view all the answers

Why is the patch precured and then secondarily bonded to the parent material in some repair methods?

To closely approximate a bolted repair. Signup and view all the answers

In what situation would a repair using a scarf joint typically be performed?

When the part is lightly loaded. Signup and view all the answers

What should be applied after the patch has cured?

Conducting mesh and finish coat Signup and view all the answers

Why are trailing edges of control panels highly vulnerable to damage?

Because of their susceptibility to lightning strikes and ground collision Signup and view all the answers

What is a typical disadvantage of resin injection repairs?

Drilling holes causes damage to the fibers Signup and view all the answers

What is involved in repairing honeycomb core on a damaged edge or panel?

Dry the part and install new core Signup and view all the answers

When are resin injection repairs typically used?

For delamination in solid laminate with small damages Signup and view all the answers

Why can repairs in the trailing edge region be difficult?

Both skins and trailing edge reinforcement may be involved Signup and view all the answers

What is the purpose of vacuum bagging in the repair process?

To add pressure and remove air during the curing process Signup and view all the answers

In what order are plies usually placed during a taper layup sequence?

Smallest ply first Signup and view all the answers

How can wet layup repairs be cured?

At elevated temperatures up to 150 °F Signup and view all the answers

What is the correct orientation for installing repair plies?

Same orientation as original plies Signup and view all the answers

What is the purpose of impregnating the plies with resin in a wet layup repair?

To ensure proper bonding between plies Signup and view all the answers

How should the temperature be increased during the curing process of a repair?

$2 °F$ to $5 °F$ ($0.5 °C$ to $3 °C$) per minute Signup and view all the answers