Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 3-1 Chemistry • Major elements - % variation
• Impurities
• Poor mechanical or environmental resistance properties • Material selection
• Process control 3-2 Physical properties • Density
• Coefficient of thermal expansion
• Melting point
• Consistent properties within operating parameters • Material selection
• Process control 3-3 Mechanical properties
• Modulus
• Surface hardness
• Low material properties • Adequate material properties
• Operational effects accounted for 3-4 Environmental resistance
• Oxidation
• Temperature range
• Corrosion
• Chemical resistance
• Physical deterioration from Oxidation/Corrosion/chemical attack
• Property reduction due to extreme temperatures
• Verify adequate environmental properties
• Verify chemical compatibility with approved engine fluids.
Section 4 – Part Materials and Processes - Processing Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 4-1 Raw material processing • Purity • Inadequate material properties • Process control (melt control, cleanliness)
• Process control and sequencing 4-2 Surface treatment • Proper form and texture • Improper thickness and excess flash • Process control 4-3 Process sequencing and Significant Process Identification and Substantiation
• Inspection
• Manufacturing
• Process Substantiation and Control (RSS,RSA,ESA, etc)
• Inadequate final part form, or defect “escape” • Verify adequate control of processes and parameters Section 5 – Analysis Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 5-1 Operating conditions
• Temperatures
• Sealing ability
• Proper contact pressures
• Location of flange surfaces
• Inadequate part life due to analysis under-predicting part temperature, mechanical stress, chemical resistance
• Perform analysis at relevant operating conditions 5-2 Variation • Engine operation characteristics • Inadequate part function due to variation • Verify part is tolerant to variation 25
Appendix 2 Section 6 – Testing Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 6-1 Durability • Engine vibration response
• Leakage
• Excessive vibration
• Excessive leakage
• Perform adequate component and/or engine testing 6-2 Operability and performance
• Vibration signature
• Abnormal wear on affected parts
• Excessive vibration
• Difficult to disassemble after operation
• Engine testing Section 7 – Potential Impact on Regulatory Requirements Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing.
This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.
Applicable 14 CFR Part 33 Regulatory Requirements Comments Subpart A – General
1. 33.4 Instructions for Continued Airworthiness Could be affected ICAs including on-wing inspection requirements and on-wing limits for leakage
2. 33.5 Instruction manual for installing and operating the engine
3. 33.7 Engine ratings and operating limitations Could be affected Adequate sealing required throughout engine operating envelope.
4. 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction;
General
5. 33.14 Start-stop cyclic stress (low cycle fatigue)
6. 33.15 Materials Could be affected
7. 33.17 Fire prevention Could be affected No fluid leakage
8. 33.19 Durability Could be affected 26
Appendix 2 Subpart B – Design and Construction;
General
9. 33.21 Engine Cooling
10. 33.23 Engine mounting attachments and structure
11. 33.25 Accessory attachments
12. 33.27 Turbine, compressor, fan, and turbosupercharger rotors
13. 33.28 Electrical and electronic control systems
14. 33.29 Instrumentation connection Subpart E – Design and Construction;
Turbine Aircraft Engines
15. 33.62 Stress Analysis
16. 33.63 Vibration Could be affected
17. 33.65 Surge and stall characteristics
18. 33.66 Bleed air systems
19. 33.67 Fuel system Could be affected Leakage limits
20. 33.68 Induction system icing (Operability aspects)
21. 33.69 Ignition system
22. 33.71 Lubrication system Could be affected Leakage limits
23. 33.72 Hydraulic actuating system
24. 33.73 Power or thrust response
25. 33.74 Continued rotation
26. 33.75 Safety Analysis
27. 33.76 Bird Ingestion (Operability aspects of ingestion)
28. 33.77 Foreign object ingestion (Operability aspects of ingestion)
29. 33.78 Rain and hail ingestion 27
Appendix 2 Subpart E – Design and Construction;
Turbine Aircraft Engines
30. 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines
31. 33.83 Vibration test
32. 33.85 Calibration tests
33. 33.87 Endurance test Could be affected Leakage limits
34. 33.88 Engine over temperature test
35. 33.89 Operation test
36. 33.90 Initial maintenance inspection Could be affected Leakage limits
37. 33.91 Engine component
38. 33.92 Rotor locking tests
39. 33.93 Teardown inspection
40. 33.94 Blade containment and rotor unbalance tests (Weight changes)
41. 33.95 Engine-propeller system tests
42. 33.96 Engine tests in auxiliary power unit (APU) mode
43. 33.97 Thrust reversers
44. 33.99 General conduct of block tests
45. Part 33 - Appendix A – Instructions for Continued Airworthiness Could be affected
46. Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 28
Appendix 2 Template #3: Combustor Nomenclature for Generic Component Features (all features may not be applicable) 29
Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 1-1 Weight • As-cast surfaces
• Machined surfaces
• Surface dimensional process control 1-2 Profile • Inner and outer wall contours
• Nozzle area
• Operability effects
• Emissions
• Turbine airfoils durability
• Surface dimensional process control 1-3 Cooling/Dilution air utilization
• Total flow rate
• Individual nozzle swirler/heatshield flow rate
• ID/OD profile
• Static pressure distribution
• Over-temperature/dysfunction
• Emissions
• Improper temperature profile: over-temperature/dysfunction of downstream airfoils
• Cooling and dilution hole dimensional process control
• Burner rig testing 1-4 Structural strength • Combustor hood locating pins • Static structure malfunction • Resonance avoidance at steady state operation with margin 1-5 Creep, LCF, fracture toughness, tensile overload capability
• Geometry
• Cooling
• Material mechanical/metallurgical/physical properties
• Crack growth from LCF or Creep – Rupture • Verify capability exceeds expected utilization Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 2-1 Inner and outer shells
• Profile and length
• Axial location of forward and aft face
• Functional fits at interfaces
• Part/assembly locating features (axial, radial and tangential)
• Air sealing surfaces
• Cooling and dilution holes
• Emissions effects
• Combustor exit profile effects (pattern factor)
• Lean blowout
• Rumble or combustion Instability
• Dimensional process control and inspection
• Burner rig testing 2-2 Hood • Fuel nozzle location
• Cooling hole location
• Leading edge profile
• Durability
• ID/OD airflow distribution
• Lean blowout
• Dimensional process control
• Burner rig testing 2-3 Fuel nozzle swirlers • Radial location
• Cooling hole pattern
• Size
• Durability • Surface dimensional process control 30
Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 2-4 Cast panels • Profile
• Cooling pin/fin size and location
• Emissions
• Durability
• Dimensional process control 2-5 Tolerance • Variance-Fluctuations in measurements
• Measurement gauge repeatability and reliability
• Mechanical/Functional, failure due to vibration from nominal • Verify part is tolerant to variation
• Control of manufacturing and inspection processes Section 3 – Part Materials and Processes – Properties Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 3-1 Chemistry • Major elements - % variation
• Impurities
• Poor mechanical or environmental properties
• Poor TBC adherence
• Material selection
• Master heat and process control 3-2 Physical properties • Density
• Coefficient of thermal expansion
• Refractive Index (x-rays)
• Excessive weight
• Excessive thermal stresses
• Interference with surrounding hardware Verify:
• Acceptable weight
• Acceptable stresses
• Combustor “fit” in hot condition 3-3 Mechanical /metallurgical properties
• Modulus (vs. grain orientation)
• Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF)
• Long term metallurgical stability
• Excessive strain-controlled stress
• Undesirable natural frequency
• Low material properties, dysfunction
• Material capability consumed in operation Verify:
• Acceptable stresses and frequencies
• Adequate material properties
• Operational effects accounted for
• Relevant properties are used 3-4 Cast structure • Grain Structure (size, shape, flow, boundaries, gamma prime size and volume fraction)
• Low angle boundaries
• Directional properties
• Hardness
• Melting Point
• Crack propagation rate
• Material property reduction due to excessive grain angle or low angle boundaries, cast panel dysfunction
• Verify that grain orientation or low angle boundaries are accounted for
• Process control and inspection 3-5 Environmental resistance
• Oxidation, corrosion, erosion, fretting resistance
• Elevated temperature (creep, diffusion, ageing, temp. gradients)
• FOD resistance
• Cracking from oxidation/corrosion pitting, dysfunction • Verify adequate environmental properties 31
Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 3-6 Environmental coating
• Coverage and thickness
• Long term stability
• Oxidation and corrosion resistance
• LCF property reduction due to poor coating selection/requirements, panel cracking
• Cracking from oxidation/corrosion pitting
• Control of chemistry and application process
• Verify thermal-mechanical compatibility with base material 3-7 Thermal barrier coating
• Coating material composition and density
• Thermal conductivity (coefficient of thermal expansion)
• Coverage and thickness uniformity
• Coating and diffusion zone microstructure
• Adhesion
• Oxidation
• Resistance to spalling, sintering and erosion
• Hardness
• Residual Stress
• Stripping requirements
• Bonding (Interface Contamination)
• Compatibility with base material/other coatings
• High thermal stresses or part temperature, swirler and panel dysfunction
• Control of chemistry and application process
• Verify part is tolerant to missing TBC
• No high TBC temperatures that accelerate spalling Section 4 – Part Materials and Processes - Processing Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 4-1 Casting cleanliness • Inclusions and porosity
• Internal surface cleanliness
• Crack growth from inclusion or porosity
• Poor coating adhesion, corrosion and oxidation
• Process control (mold setup, casting process, and filtration)
• Process control and sequencing 4-2 Heat treatment • Time @ temperature and ramp rates
• Manufacturing sequence
• Atmosphere
• Incorrect Gamma Prime size/spacing leading to low material properties
• Process control and sequencing 32
Appendix 2 Section 4 – Part Materials and Processes - Processing Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 4-3 Welding and brazing Effect on base material properties, based on the following:
• Weld or braze strength
• Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction
• Porosity
• Diffusion zone (brazing)
• Heat affected zone (welding)
• Penetration (welding)
• Excess braze allowance
• Filler metal selection
• Material property reduction • Correct sequencing of braze or weld cycles in the process
• Process control 4-4 Material removal – Non traditional (EDM, ECM, Laser, Water-Jet, etc.)
and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.)
Micro cracks or recast:
• Inherent to the process
• Due to abusive machining Fatigue capability degradation, due to:
• Surface finish
• Stress risers
• Chemical attack
• Cracking initiation from micro-cracks or re-cast • Verify part is tolerant to proposed limits
• Process control 4-5 Non-destructive testing (NDT)
• Acceptance limits
• Sensitivity
• Cracking from excessive defect size • Verify part is tolerant to allowable defects 4-6 Process sequencing and Significant Process Identification and Substantiation
• Inspection
• Manufacturing
• Process substantiation and control (RSS, RSA, ESA, etc)
• Inadequate final part form, or defect “escape”, dysfunction
• Verify adequate control of processes and parameters Section 5 – Analysis Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 5-1 Operating conditions
• Flow path temperatures, pressures, and velocities
• Nozzle area
• Exit profile
• Compressor operability
• Turbine airfoil durability
• Perform analysis at relevant operating conditions 5-2 Swirler cooling • Secondary flow circuit
• Swirler cooling flow
• Inadequate part life due to analysis over-predicting the swirler cooling effectiveness 33
Appendix 2 Section 5 – Analysis Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 5-3 LCF/TMF life analysis
• Temperature effects
• Multi-axial effects
• Hold time effects
• Mean stress effects
• Notch effects
• Coating effects
• Mesh size Inadequate part life due to analysis
• Using incorrect properties
• Failing to address the ‘key characteristics’
• Use applicable properties
• Select mesh size to correctly model the geometry 5-4 HCF life analysis • Temperature effects
• Vibration and mean stress effects
• Combustor resonant vibration, cracking, dysfunction • Use applicable properties and Goodman Diagram 5-5 Creep and rupture life analysis
• Temperature effects
• Material thickness effects
• Combustor rupture cracking, dysfunction • Use applicable properties 5-6 Fracture mechanics • Temperature effects
• Threshold stress intensity
• Crack growth rate
• Crack growth from defect • Use applicable dA/dN curve
• Predict K using expected defect size 5-7 Tolerance to missing TBC
• Part temperature
• Thermal stress
• High thermal stress or part temperature, dysfunction • Perform analysis with predicted TBC loss Section 6 – Testing Section/Number Characteristic Critical to Part Functionality Key Characteristics Part and System Failure Modes Risk Mitigation and Control 6-1 Durability • Fatigue
• Corrosion (hot and cold)
• Erosion
• Stress rupture
• Tensile strength
• Cooling Effectiveness 6-2 Over-temperature • Microstructure
• Creep
• Hot corrosion
• Tensile strength 6-3 Emissions • Smoke, HC, CO, NoX 34
Appendix 2 Section 7 – Potential Impact on Regulatory Requirements Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing.
This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.
Applicable 14 CFR Part 33 Regulatory Requirements Comments Subpart A – General
1. 33.4 Instructions for Continued Airworthiness Could be affected ICAs including on-wing inspection requirements and on-wing limits
2. 33.5 Instruction manual for installing and operating the engine
3. 33.7 Engine ratings and operating limitations
4. 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction;
General
5. 33.14 Start-stop cyclic stress (low cycle fatigue)
6. 33.15 Materials Could be affected
7. 33.17 Fire prevention
8. 33.19 Durability Could be affected
9. 33.21 Engine cooling Could be affected
10. 33.23 Engine mounting attachments and structure
11. 33.25 Accessory attachments
12. 33.27 Turbine, compressor, fan, and turbosupercharger rotors
13. 33.28 Electrical and electronic control systems
14. 33.29 Instrumentation connection 35
Appendix 2 Subpart E – Design and Construction;
Turbine Aircraft Engines
15. 33.62 Stress analysis
16. 33.63 Vibration
17. 33.65 Surge and stall characteristics Could be affected In-flight relighting
18. 33.66 Bleed air systems
19. 33.67 Fuel system
20. 33.68 Induction system icing (Operability aspects)
21. 33.69 Ignition system
22. 33.71 Lubrication system
23. 33.72 Hydraulic actuating system
24. 33.73 Power or thrust response Could be affected Timed accels
25. 33.74 Continued rotation
26. 33.75 Safety analysis Could be affected Combustor part release – downstream effects
27. 33.76 Bird ingestion (Operability aspects of ingestion)
28. 33.77 Foreign object ingestion (Operability aspects of ingestion)
29. 33.78 Rain and hail ingestion
30. 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines
31. 33.83 Vibration test
32. 33.85 Calibration tests
33. 33.87 Endurance test Could be affected Combustor durability and starting capability
34. 33.88 Engine over temperature test
35. 33.89 Operation test 36