Appendix 2 61
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated.
Repair Properties and Requirements to be Identified and Substantiated.
6. Evaluate any degradation in the part’s function or durability due to the following processes, when applicable, and assess its impact, if any, on existing ICAs.
a. Machining, Milling, Broaching, or Grinding
b. Non-traditional Machining
c. Welding, Brazing or Coating
d. Straightening, Retwisting, Re-forming
e. Blending
f. Honing
g. Lapping
h. Grit Blast
i. Stripping
j. Cleaning (Chemical, power flash, Ultrasonic)
k. Residual Plating, Stripping, or Cleaning Agents
l. Stress Intensity Factor (Kt)
m. Heat Treatment (time, temp, atmosphere, etc.)
n. Plating
o. Dimensional Short-falls
p. Repetitive or Conflicting Repairs
q. Contamination
7. Establish the Applicability of the Repair and the Repair Processing Sequence or evaluate any changes to an existing repair sequence for potential impact on the airworthiness of the part.
Appendix 2 62
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
8. Select all that may be potentially affected by the repair design, and evaluate system effect(s):
a. Structural Strength, including major load paths
b. Heat Transfer
c. Secondary Airflow
d. Aerodynamics
e. Weight
f. Center of Gravity
g. Moment of Weight
Critical Measurable Characteristics
9. Establish Measurable Characteristics and the allowable tolerances for the repaired part features and for any replacement detail(s) and give due consideration to mating part(s):
a. Surface finish/texture
b. Shotpeen Intensity/Coverage
c. Bearing bore dimensions and location characteristics
d. Pressure Strength test
e. Flow Capacity test
f. Dimensions, including heat distortion effects
g. Roundness
h. Flatness
i. Parallelism
j. Concentricity
k. True Position Tolerances
l. Edge Distance Requirements
m. Finish Dimensions Requirements
n. Diameter/Locating
o. Air Swirler Features
p. Mixing Air (dilution) Features
q. Datum Location Features
r. Air Cooling Hole Diameter
s. Flowpath Exit Features
t. Sealing Features
u. Aft Seal
v. Fuel Nozzles
w. Igniter interfaces
x. Flanges
Appendix 2 63
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
10. Cooling Feature Characteristics:
a. Airflow
b. Hole Diameter
c. Blocked Hole Quantity/Location
d. Cooling Slot Height/Length/Location
e. Quantity of Holes/Slots
11. Thermal Barrier Coating:
a. Thickness
b. Coverage
c. Type
Repair Process Capability Technical Substantiation Requirements
12. Verification Plan with Significant Operations Identified for Repair Source Qualification
Appendix 2 64
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
8 Repair Process Capability Technical Substantiation Requirements
13. Process Demonstration Including:
a. Variability Requirements
14. Part Demonstration/Inspection
15. Manufacturing Requirements for fabrication of repair details or replacement sections to accomplish repair:
a. Drawings/Specifications
b. Quality Requirements
c. Source Substantiation Requirements
Applicable 14 CFR Part 33 Requirements
Subpart A – General
16. 33.4 Instructions for Continuous Airworthiness (ICA's)
17. 33.5 Instruction Manual for Installing and Operating the Engine
18. 33.7 Engine Ratings and Operating Limitations
19. 33.8 Selection of Engine Power and Thrust Ratings
Subpart B – Design and Construction; General
20. 33.14 Start-stop cyclic stress (low cycle fatigue)
21. 33.15 Materials
22. 33.17 Fire prevention
23. 33.19 Durability (Note that 33.19 is associated with 33.27; 33.63; 33.83;
33.87; 33.88; and 33.90)
24. 33.21 Engine
25. 33.23 Engine mounting attachments and structure
26. 33.25 Accessory attachments
Appendix 2 65
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
27. 33.27 Turbine, compressor, fan, and turbo supercharger rotors
28. 33.28 Electrical and electronic control systems
29. 33.29 Instrument connection Subpart E – Design and Construction; Turbine Aircraft Engines
30. 33.62 Stress analysis
31. 33.63 Vibration
32. 33.65 Surge and stall characteristics, (Note 2)
33. 33.66 Bleed air system
34. 33.67 Fuel system
35. 33.68 Induction system icing, (operability aspects) (Note 2)
36. 33.69 Ignitions system
37. 33.71 Lubrication system
38. 33.72 Hydraulic actuating systems
39. 33.73 Power or thrust response
40. 33.74 Continued rotation
41. 33.75 Safety analysis
42. 33.76 Bird ingestion (operability aspects of ingestion)
43. 33.77 Foreign object ingestion—ice (operability aspects of ingestion)
44. 33.78 Rain and hail ingestion
45. 33.79 Fuel burning thrust augmentor Subpart F – Block Tests; Turbine Aircraft Engines
46. 33.83 Vibration test
47. 33.85 Calibration tests
48. 33.87 Endurance tests
49. 33.88 Engine overtemperature test
50. 33.89 Operation test (Note 2)
51. 33.90 Initial maintenance inspection
52. 33.91 Engine component tests (HCF/LCF Bench Testing)
53. 33.92 Rotor locking tests
54. 33.93 Teardown inspection
Appendix 2 66
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
55. 33.94 Blade containment and rotor unbalance tests (weight changes)
56. 33.95 Engine-propeller system tests
57. 33.96 Engine tests in auxiliary power unit (APU) mode
58. 33.97 Thrust reversers
59. 33.99 General conduct of block tests Part 33-Appendix A – Instructions for Continued Airworthiness
Part 33-Appendix B- Certification Standard Atmospheric Concentrations of Rain and Hail
Part 34 – Exhaust Emissions
Appendix 2 67 Template 6
REPAIR SUBSTANTIATION CHECKLIST - EXTERNALS PART FAMILY (Tubes, Manifolds, Ducts, Brackets)
Categories of Externals (Tubes, Manifolds, Ducts, Brackets) Part Family. Determine which repair description best fits the repair proposal. If no repair description is appropriate, contact the FAA Advisor for guidance.
CATEGORIES
OF REPAIRS
REPAIR DESCRIPTION
1. Assembly and/or Disassembly This repair assembles, disassembles, removes and replaces detail parts, or subassemblies without use of permanent attachment techniques (i.e.; welding or brazing). Assembly is either bolted or riveted.
2. Weld or Braze Repair This repair excludes detail part replacement
3. Weld or Braze Repair Includes detail part replacement
4. Blend Repair
5. Sulfidation or Corrosion Repair
6. Dimensional Restoration by Coating or Plating
7. Bushing/Helicoil Repair
8. Straightening, Re-twist or Reforming Repair This repair includes dent repair
9. Repairs to Restore Adhesives, Bonding Agents, Potting Compounds.
10. Machining Repair This repair includes lapping, skim cut, non-conventional machining
Appendix 2 68
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
1. Applicable Degradation Modes: Select all that apply based on the function of the part and its operating environment in the engine. This section provides the background for establishing the substantiation requirements.
a. Thermo-mechanical fatigue
b. Oxidation
c. Corrosion
d. Elevated temperature-induced changes (creep, diffusion, ageing, temperature gradients)
e. Wear due to: adhesion, abrasion, corrosion, erosion, cavitation, fretting, oxidation
f. High-cycle fatigue
g. Rubbing, foreign object impact damage, O3 chemical attack, etc.
Appendix 2 69
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
2. Select all mechanical, metallurgical, and physical properties of the part affected by the repair design and assess their impact on the part’s airworthiness:
Mechanical Properties:
a. Stress-Strain
b. Fracture Toughness
c. Fatigue Strength (S-N, Goodman, Dwell Time)
d. Creep
e. Tensile Properties (Yield, Strength, Elongation)
f. Hardness
g. Young’s Modulus
h. Natural Frequencies
Metallurgical Properties:
i. Chemical Composition (Alloy constituents)
j. Microstructure (grain size – shape - boundary precipitates, gamma prime size and volume fraction, etc.)
k. Melting Point
l. Corrosion Resistance
m. Oxidation Resistance
n. Wear Resistance (Consider wear types in (1)(e))
o. Crack Propagation Rate
Physical Properties:
p. Density (weight)
q. Coefficient of Thermal Expansion
r. Refractive Index (X-Rays)
s. Center of Gravity
t. Polar Moment of Inertia
Appendix 2 70
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
3. Select all Material Properties/Characteristics for weldments or brazed joints that apply and evaluate them and their interface with the parent metal. The effect of any changes to the part’s metallurgy as a result of welds or braze should be evaluated for airworthiness.
a. Microstructure (grain size, grain shape, grain boundary precipitates, gamma prime size and volume fraction, etc.)
b. Porosity (weldment)
c. Diffusion Zone (brazing)
d. Heat Affected Zone (welding)
4. Coating & Plating Material Properties Characteristics & Processes:
a. Deposited Material Composition
b. Thickness, Coverage & Uniformity
c. Microstructure
d. Hardness
e. Sintering
f. Strip Process
g. Residual Stress
h. Lubricant Properties
i. Spalling Resistance
j. Thermal Resistance
k. Erosion Resistance
l. Bonding (Interface Contamination)
m. Environmental Resistance
n. Diffusion Zone
o. Hydrogen Embrittlement Free (Plating)
p. Compatibility With Base Material
q.
5. Select Surface Treatment that applies (without material removal) and evaluate effect(s), if any, on airworthiness:
a. Burnishing
b. Peening
c. Butterfly Polish
d. Mass Media Finishing
Appendix 2 71
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
6. Evaluate any degradation in the part’s function or durability due to the following processes, when applicable, and assess its impact, if any, on existing ICAs.
a. Machining, Milling, Broaching, or Grinding
b. Non-traditional Machining
c. Welding, Brazing or Coating
d. Straightening, re-twisting, reforming
e. Blending
f. Honing
g. Lapping
h. Grit Blast
i. Stripping
j. Cleaning (Chemical, power flash, Ultrasonic)
k. Residual Plating, Stripping, or Cleaning Agents
l. Stress Intensity Factor (Kt)
m. Heat Treatment (time, temp, atmosphere, etc.)
n. Plating
o. Dimensional Short-falls
p. Repetitive or Conflicting Repairs
q. Contamination
Appendix 2 72
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
7. Establish the Applicability of the Repair and the Repair Processing Sequence or evaluate any changes to an existing repair sequence for potential impact on the airworthiness of the part.
8. Select all that may be potentially affected by the repair design and evaluate system effect(s):
a. Structural Strength, including major load paths
b. Heat Transfer
c. Secondary Airflow
d. Aerodynamics
e. Weight
f. Center of Gravity
g. Moment of Weight
Critical Measurable Characteristics
9. Establish Measurable Characteristics and the allowable tolerances for the repaired part features and for any replacement detail(s) and give due consideration to mating part(s):
a. Surface finish/texture
b. Shotpeen intensity/coverage
c. Bearing bore dimensions and location characteristics
d. Pressure strength test
e. Flow capacity test
f. Dimensions, including heat distortion effects Roundness Flatness Parallelism Concentricity True position tolerances Edge distance requirements Finish dimensions requirements
10. Coating Coverage Definition
11. Blend Area Proximity Limits Defined