Repair

Question 1

Define Quality Assurance

Answer 1

specific classes of repair need to be defined and determined by best engineering
practices. Apply judgment
(General Repair Specification)
Repair classifications
Rework
Standard repair
Material Review Board (MRB) - Quality Assurance and Engineering

Question 2

A four-class system was described in the note, give a general outline of those classes.

Answer 2

• Class IV - cosmetic, negligible repair - rework - non-structural repairs to bring part up to
required drawing finish
• Class III - minor structural repair - standard repair procedure applicable
• Class II - major structural repair - standard repair procedure applicable
• Class I - major structural repair - requires MRB (Material Review Board) review

Question 3

List several types of composite repairs.

Answer 3

bolt on repair; filling - resin/adhesive/syntactic foam/composite; removing/filling - scarf repair

Question 4

List several types of repair materials.

Answer 4

Resins/adhesives – viscosity issues, cure time and temperature; syntactic foam/foaming adhesives;
reinforcing fabric, milled fibers; preimpregnated fabric and tape

Question 5

List some advantages of Different Systems.

Answer 5

Wet - room temperature cure, can use minimal process materials and equipment
Prepreg - resin content control; cleaner to work with; may provide better match with existing material.

Question 6

What are the general repair procedures?

Answer 6

a. surface preparation;
b. application of material,
c. cure: time, temperature, and pressure;
d. finishing