Appendix 2 121
CATEGORIES OF REPAIRS Req No.
Repair Properties and Requirements to be Identified and Substantiated.
1 2 3 4 5 6 7 8 9 10 Subpart F – Block Tests; Turbine Aircraft Engines
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 test
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
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 2 122 Template 12
REPAIR SUBSTANTIATION CHECKLIST - MAJOR ROTATING (NON-LIFE
LIMITED) PART FAMILY (EXCLUDING TURBINE SHAFT COUPLING PART
FAMILY)
Categories of Major Rotating (Non-Life Limited) Part Repairs. 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. Restoration of Protective Coating (Paint, Aluminizing, Oil, etc.)
Includes touch-up coating
2. Weld or Braze Repair This repair excludes detail part replacement
3. Assembly and/or Disassembly This repair assembles, disassembles, removes and replaces detail parts, or sub - assemblies without use of permanent attachment techniques (i.e.; welding or brazing).
Assembly is either bolted or riveted
4. Blend Repair
5. Remove and Restore Anti-gallant
6. Dimensional Restoration by Coating or Plating
7. Bushing/Helicoil Repair
8. Honing Repair
9. Machining Repair This repair includes lapping, skim cut, non-conventional machining
Appendix 2 123
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 2 124
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 2 125
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
Appendix 2 126
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. Repair Properties and Requirements to be Identified and Substantiated.
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
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 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 2 127
CATEGORIES OF REPAIR Req No.
Repair Design Requirements to be Identified and Substantiated. 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
g. 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
12. No Grit Blast/Coating in Fillet Radii
Appendix 2 128
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
9 Repair Process Capability Technical Substantiation Requirements
13. Verification Plan with Significant Operations Identified for Repair Source Qualification
14. Process Demonstration (including variability requirements)
15. Part Demonstration/Inspection
16. Manufacturing requirements for fabrication of repair details or replacement sections used to accomplish repair:
Drawings/Specifications Quality Requirements Source Substantiation Requirements
Applicable 14 CFR Part 33 Requirements
Subpart A – General
17. 33.4 Instructions for Continuous Airworthiness (ICA's)
18. 33.5 Instruction manual for installing and operating the engine
19. 33.7 Engine ratings and operating limitations
20. 33.8 Selection of engine power and thrust ratings
Subpart B – Design and Construction;
General
21. 33.14 Start-stop cyclic stress (low cycle fatigue)
22. 33.15 Materials
23. 33.17 Fire prevention
24. 33.19 Durability (Note that 33.19 is associated with 33.27; 33.63; 33.83; 33.87;
33.88; and 33.90)
25. 33.21 Engine cooling
Appendix 2 129
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
9 Subpart B – Design and Construction;
General
26. 33.23 Engine mounting attachments and structure
27. 33.25 Accessory attachments
28. 33.27 Turbine, compressor, fan, and turbosupercharger
29. 33.28 Electrical and electronic control systems
30. 33.29 Instrument connection Subpart E – Design and Construction;
Turbine Aircraft Engines
31. 33.62 Stress analysis
32. 33.63 Vibration
33. 33.65 Surge and stall characteristics (Note 2)
34. 33.66 Bleed air system
35. 33.67 Fuel system
36. 33.68 Induction system icing (operability aspects) (Note 2)
37. 33.69 Ignitions system
38. 33.71 Lubrication system
39. 33.72 Hydraulic actuating systems
40. 33.73 Power or thrust response
41. 33.74 Continued rotation
42. 33.75 Safety analysis
43. 33.76 Bird ingestion (operability aspects of ingestion)
44. 33.77 Foreign object ingestion—ice (operability aspects of ingestion)
45. 33.78 Rain and hail ingestion
46. 33.79 Fuel burning thrust augmentor
Appendix 2 130
CATEGORIES OF REPAIR Req No.
Repair Properties and Requirements to be Identified and Substantiated.
9 Subpart F – Block Tests; Turbine Aircraft Engines
47. 33.83 Vibration test
48. 33.85 Calibration tests
49. 33.87 Endurance test
50. 33.88 Engine overtemperature test
51. 33.89 Operation test (Note 2)
52. 33.90 Initial maintenance inspection
53. 33.91 Engine component tests (HCF/LCF bench testing)
54. 33.92 Rotor locking tests
55. 33.93 Teardown inspection
56. 33.94 Blade containment and rotor unbalance tests (weight changes)
57. 33.95 Engine-propeller system tests
58. 33.96 Engine tests in auxiliary power unit (APU) mode
59. 33.97 Thrust reversers
60. 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 2 131 Template 13
REPAIR SUBSTANTIATION CHECKLIST – HIGH PRESSURE COMPRESSOR (HPC)/HIGH PRESSURE TURBINE (HPT)/LOW PRESSURE TURBINE (LPT)
AIRSEALS (NON-ROTATING) AND SHROUDS (STATIONARY) PART FAMILY
Categories of HPC/HPT/LPT Airseals (non-rotating) and Shrouds (stationary) Part Family Repair. Determine which repair description best fit 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 sub - assemblies without use of permanent attachment techniques (i.e.; welding or brazing). Assembly is either bolted or riveted
2. Blend Repair
3. Strip and Re-coat Repair This repair removes and replaces any and all types of coatings
4. Dimensional Restoration by Coating or Plating
5. Weld or Braze Repair This repair excludes detail part replacement)
6. Weld or Braze Repair This repair includes part detail replacement
7. Straightening, Re-twist or Reforming Repair This repair includes dent repair
8. Machining Repair This repair includes lapping, skim cut, non-conventional machining
Appendix 2 132
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.