Appendix 2 FIGURE A2-5
e. This strategy essentially accelerates the piece part exposure rate as shown in FIGURE A2-5. By iterating on the length of the soft time interval, a 12,300 cycle value is found to yield a POF of 1.0 E-09 events for each cycle, satisfying the DTR criteria. The design would be considered acceptable relative to damage tolerance criteria and the following inspection requirements would be placed in the Airworthiness Limitations Section of the Instructions for Continued Airworthiness (Step
12):
(1) Inspect at first piece part exposure.
(2) For parts not previously inspected before 12,300 cycles, inspect at first module exposure above 12,300 cycles, soft time inspection interval.
(3) UT inspection calibrated to a #3 FBH.
(4) Reject indications equal to or greater than ½ the response from a number 3 FBH calibration.
(5) Include reference to detailed UT inspection procedures.
f. The information provided in this section is for example only. Each individual component design and engine maintenance practice may require different solutions than those presented here.
The key is that Airworthiness Limitations Section of the Instructions for Continued Airworthiness requirements should reflect actions consistent with the analytical assumptions made to meet the DTR criteria.
A2-7
Appendix 3 APPENDIX 3
DEFAULT ANOMALY DISTRIBUTION CURVES
1. Anomaly Distribution Curves
a. The anomaly distribution curves associated with hard-alpha inclusions in titanium engine
rotors are illustrated in this Appendix (FIGURES A3-1 - A3-4). The corresponding tabular data is listed in Table A3-1 of this Appendix. The following text provides additional information
associated with the use of these distributions.
(1) The distributions are applicable to material that is conventionally inspected in billet form. Here, the term “conventional” means that the ultrasonic inspection technique treats all billet radial positions in the same manner (i.e., is not enhanced in a zoned based approach such as that described in AMS 2628).
(2) The distributions are applicable only to hard-alpha inclusions in rotor grade (premium) titanium melted after 1995 using triple VAR or CHM plus VAR processes.
(3) It is crucial to use the appropriate distribution curve that accurately reflects the inspection sensitivities performed at the billet and forging stages of the manufacturing process.
(4) For example, the material must be inspected using UT to at least a
#3 FBH with the reject level set at one half that of the calibration level. See Appendix 5 for
additional instructions. Inspections must be performed at both the billet and sonic shape stages.
(5) The distribution accounts for all steps required to manufacture a finished part, including the in-process billet and sonic shape forging ultrasonic inspections. Therefore, the distribution used should reflect the inspection sensitivities used in the billet and forging inspections, and should not be altered.
(6) Referring to the FIGURES in this Appendix:
(a) The vertical axis represents the rate (per million pounds) of anomalies exceeding a given size on the horizontal axis. The curve represents a statistical distribution of anomaly sizes that may be used to assess component risk.
(b) The horizontal axis is the inclusion cross-sectional area including the hard-alpha core and the surrounding diffusion zone. A circular inclusion cross section should be assumed with the corresponding diameter used as the initial size in the crack growth analysis.
A3-1
Appendix 3 FIGURE A3-1 Triple Melt/Cold Hearth + Var Hard Alpha Inclusion Distribution Billet conventional inspection calibrated to #5 FBH / Forging Conventional inspection calibrated to #3 FBH
1.E+01
1.E-02
1.E-03 100 1,000 10,000 100,000 1,000,000 Defect Area (mils-) FIGURE A3-2 Triple Melt/Cold Hearth + VAR Hard Alpha Inclusion Distribution Billet conventional inspection calibrated to #3 FBH / Forging Conventional inspection calibrated to #3 FBH Evenine permiton one) 1.E-01
1.E-03 100 1.000 10,000 100.000 1.000.000 Defect Area (mils*) A3-2
Appendix 3 FIGURE A3-3 Triple Melt/Cold Hearth + VAR Hard Alpha Inclusion Distribution Billet conventional inspection calibrated to #3 FBH / Forging Conventional insection calibrated to #2 FBH Exceedance (per million pounds)
1.E-02 15-03 1 100 1,000 10,000 100,000 1,000,000 Defect Area (mils-) FIGURE А3-4 Triple Melt/Cold Hearth + VAR Hard Alpha Inclusion Distribution Billet conventional inspection calibrated to #3 FBH / Forging Conventional insection calibrated to #1 FBH
1.E+01 100 1,000 10.000 100.000 1.000.000 Defect Area (mils*) A3-3
Appendix 3 Table A3-1. Tabular Data – Anomaly Distribution Curves (Figures A3-1 – A3-4) A3-4 Billet #5 Billet #3 Billet #3 Billet #3 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Forging #3 Forging #3 Forging #2 Forging #1 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Area exceedance exceedance exceedance exceedance sq mils per million lbs per million lbs per million lbs per million lbs
3.52 8.81E+00 8.76E+00 8.66E+00 8.35E+00
3.73 8.62E+00 8.57E+00 8.47E+00 8.16E+00
3.94 8.43E+00 8.38E+00 8.28E+00 7.98E+00
4.17 8.25E+00 8.20E+00 8.10E+00 7.79E+00
4.41 8.07E+00 8.02E+00 7.92E+00 7.62E+00
4.67 7.90E+00 7.84E+00 7.75E+00 7.44E+00
4.94 7.73E+00 7.67E+00 7.57E+00 7.27E+00
5.23 7.56E+00 7.50E+00 7.41E+00 7.10E+00
5.53 7.39E+00 7.34E+00 7.24E+00 6.94E+00
5.85 7.23E+00 7.18E+00 7.08E+00 6.78E+00
6.19 7.08E+00 7.02E+00 6.92E+00 6.62E+00
6.55 6.92E+00 6.87E+00 6.77E+00 6.47E+00
6.92 6.77E+00 6.72E+00 6.62E+00 6.31E+00
7.33 6.62E+00 6.57E+00 6.47E+00 6.17E+00
7.75 6.48E+00 6.42E+00 6.33E+00 6.02E+00
8.20 6.34E+00 6.28E+00 6.18E+00 5.88E+00
8.67 6.20E+00 6.14E+00 6.05E+00 5.74E+00
9.18 6.06E+00 6.01E+00 5.91E+00 5.60E+00
9.71 5.93E+00 5.87E+00 5.78E+00 5.47E+00
10.3 5.80E+00 5.74E+00 5.65E+00 5.34E+00
10.9 5.67E+00 5.61E+00 5.52E+00 5.21E+00
11.5 5.54E+00 5.49E+00 5.39E+00 5.09E+00
12.2 5.42E+00 5.37E+00 5.27E+00 4.96E+00
12.9 5.30E+00 5.25E+00 5.15E+00 4.84E+00
13.6 5.18E+00 5.13E+00 5.03E+00 4.73E+00
14.4 5.07E+00 5.01E+00 4.92E+00 4.61E+00
15.2 4.96E+00 4.90E+00 4.80E+00 4.50E+00
16.1 4.84E+00 4.79E+00 4.69E+00 4.39E+00
17.0 4.74E+00 4.68E+00 4.58E+00 4.28E+00
18.0 4.63E+00 4.58E+00 4.48E+00 4.17E+00
19.1 4.53E+00 4.47E+00 4.37E+00 4.07E+00
20.2 4.42E+00 4.37E+00 4.27E+00 3.97E+00
21.3 4.33E+00 4.27E+00 4.17E+00 3.87E+00
22.6 4.23E+00 4.17E+00 4.08E+00 3.77E+00
23.9 4.13E+00 4.08E+00 3.98E+00 3.68E+00
25.3 4.04E+00 3.98E+00 3.89E+00 3.58E+00
26.7 3.95E+00 3.89E+00 3.79E+00 3.49E+00
Appendix 3 Table A3-1. Tabular Data – Anomaly Distribution Curves (Figures A3-1 – A3-4) A3-5 Billet #5 Billet #3 Billet #3 Billet #3 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Forging #3 Forging #3 Forging #2 Forging #1 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Area exceedance exceedance exceedance exceedance sq mils per million lbs per million lbs per million lbs per million lbs
28.3 3.86E+00 3.80E+00 3.70E+00 3.40E+00
29.9 3.77E+00 3.71E+00 3.62E+00 3.31E+00
31.7 3.68E+00 3.63E+00 3.53E+00 3.23E+00
33.5 3.60E+00 3.54E+00 3.45E+00 3.14E+00
35.4 3.52E+00 3.46E+00 3.36E+00 3.06E+00
37.5 3.44E+00 3.38E+00 3.28E+00 2.98E+00
39.7 3.36E+00 3.30E+00 3.20E+00 2.90E+00
42.0 3.28E+00 3.22E+00 3.13E+00 2.82E+00
44.4 3.20E+00 3.15E+00 3.05E+00 2.75E+00
46.9 3.13E+00 3.07E+00 2.98E+00 2.67E+00
49.7 3.06E+00 3.00E+00 2.90E+00 2.60E+00
52.5 2.98E+00 2.93E+00 2.83E+00 2.53E+00
55.6 2.91E+00 2.86E+00 2.76E+00 2.46E+00
58.8 2.85E+00 2.79E+00 2.69E+00 2.39E+00
62.2 2.78E+00 2.72E+00 2.63E+00 2.32E+00
65.8 2.71E+00 2.66E+00 2.56E+00 2.26E+00
69.6 2.65E+00 2.59E+00 2.50E+00 2.19E+00
73.7 2.59E+00 2.53E+00 2.43E+00 2.13E+00
77.9 2.52E+00 2.47E+00 2.37E+00 2.07E+00
82.4 2.46E+00 2.41E+00 2.31E+00 2.01E+00
87.2 2.40E+00 2.35E+00 2.25E+00 1.95E+00
92.3 2.35E+00 2.29E+00 2.19E+00 1.89E+00
97.6 2.29E+00 2.23E+00 2.14E+00 1.83E+00 103 2.23E+00 2.18E+00 2.08E+00 1.78E+00 109 2.18E+00 2.12E+00 2.03E+00 1.72E+00 116 2.13E+00 2.07E+00 1.97E+00 1.67E+00 122 2.07E+00 2.02E+00 1.92E+00 1.62E+00 129 2.02E+00 1.97E+00 1.87E+00 1.57E+00 137 1.97E+00 1.92E+00 1.82E+00 1.52E+00 145 1.92E+00 1.87E+00 1.77E+00 1.47E+00 153 1.88E+00 1.82E+00 1.72E+00 1.42E+00 162 1.83E+00 1.77E+00 1.68E+00 1.38E+00 171 1.78E+00 1.73E+00 1.63E+00 1.33E+00 181 1.74E+00 1.68E+00 1.59E+00 1.28E+00 192 1.69E+00 1.64E+00 1.54E+00 1.24E+00 203 1.65E+00 1.60E+00 1.50E+00 1.20E+00 215 1.61E+00 1.55E+00 1.46E+00 1.16E+00 227 1.57E+00 1.51E+00 1.41E+00 1.12E+00
Appendix 3
Billet #5 Billet #3 Billet #3 Billet #3
FBH conv/ FBH conv/ FBH conv/ FBH conv/ Forging #3 Forging #3 Forging #2 Forging #1 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Area exceedance exceedance exceedance exceedance sq mils per million lbs per million lbs per million lbs per million lbs 240 1.52E+00 1.47E+00 1.37E+00 1.08E+00 254 1.49E+00 1.43E+00 1.33E+00 1.04E+00 269 1.45E+00 1.39E+00 1.29E+00 9.97E-01 284 1.41E+00 1.35E+00 1.26E+00 9.60E-01 301 1.37E+00 1.32E+00 1.22E+00 9.23E-01 318 1.33E+00 1.28E+00 1.18E+00 8.87E-01 337 1.30E+00 1.24E+00 1.15E+00 8.52E-01 356 1.26E+00 1.21E+00 1.11E+00 8.18E-01 377 1.23E+00 1.17E+00 1.08E+00 7.85E-01 399 1.19E+00 1.14E+00 1.04E+00 7.52E-01 422 1.16E+00 1.11E+00 1.01E+00 7.20E-01 446 1.13E+00 1.08E+00 9.79E-01 6.89E-01 472 1.10E+00 1.04E+00 9.47E-01 6.59E-01 499 1.07E+00 1.01E+00 9.16E-01 6.29E-01 528 1.04E+00 9.82E-01 8.86E-01 6.00E-01 559 1.01E+00 9.53E-01 8.57E-01 5.72E-01 591 9.78E-01 9.24E-01 8.28E-01 5.45E-01 626 9.49E-01 8.95E-01 7.99E-01 5.19E-01 662 9.21E-01 8.67E-01 7.72E-01 4.93E-01 700 8.94E-01 8.40E-01 7.44E-01 4.68E-01 741 8.67E-01 8.13E-01 7.18E-01 4.43E-01 784 8.41E-01 7.87E-01 6.92E-01 4.20E-01 829 8.15E-01 7.62E-01 6.67E-01 3.97E-01 877 7.90E-01 7.37E-01 6.42E-01 3.75E-01 928 7.65E-01 7.12E-01 6.17E-01 3.53E-01 981 7.41E-01 6.88E-01 5.94E-01 3.33E-01 1,038 7.18E-01 6.64E-01 5.70E-01 3.13E-01 1,098 6.95E-01 6.41E-01 5.48E-01 2.94E-01 1,162 6.72E-01 6.19E-01 5.26E-01 2.75E-01 1,229 6.50E-01 5.97E-01 5.04E-01 2.58E-01 1,300 6.28E-01 5.75E-01 4.83E-01 2.41E-01 1,376 6.07E-01 5.54E-01 4.62E-01 2.25E-01 1,455 5.87E-01 5.34E-01 4.42E-01 2.10E-01 1,540 5.66E-01 5.14E-01 4.22E-01 1.95E-01 1,629 5.46E-01 4.94E-01 4.03E-01 1.82E-01 1,723 5.27E-01 4.75E-01 3.84E-01 1.69E-01 1,823 5.08E-01 4.56E-01 3.66E-01 1.57E-01 1,929 4.89E-01 4.37E-01 3.48E-01 1.46E-01
Table A3-1. Tabular Data – Anomaly Distribution Curves (Figures A3-1 – A3-4) A3-6
Appendix 3 Table A3-1. Tabular Data – Anomaly Distribution Curves (Figures A3-1 – A3-4) Billet #5 Billet #3 Billet #3 Billet #3 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Forging #3 Forging #3 Forging #2 Forging #1 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Area exceedance exceedance exceedance exceedance sq mils per million lbs per million lbs per million lbs per million lbs 2,158 4.53E-01 4.02E-01 3.14E-01 1.25E-01 2,283 4.36E-01 3.85E-01 2.98E-01 1.17E-01 2,416 4.19E-01 3.68E-01 2.82E-01 1.09E-01 2,556 4.02E-01 3.51E-01 2.66E-01 1.01E-01 2,704 3.86E-01 3.36E-01 2.51E-01 9.47E-02 2,860 3.70E-01 3.20E-01 2.37E-01 8.88E-02 3,026 3.55E-01 3.05E-01 2.22E-01 8.37E-02 3,201 3.40E-01 2.90E-01 2.09E-01 7.92E-02 3,386 3.25E-01 2.76E-01 1.96E-01 7.53E-02 3,583 3.11E-01 2.61E-01 1.83E-01 7.21E-02 3,790 2.97E-01 2.48E-01 1.71E-01 6.92E-02 4,009 2.83E-01 2.35E-01 1.59E-01 6.65E-02 4,242 2.69E-01 2.22E-01 1.48E-01 6.38E-02 4,487 2.56E-01 2.09E-01 1.37E-01 6.12E-02 4,747 2.44E-01 1.97E-01 1.27E-01 5.86E-02 5,022 2.31E-01 1.85E-01 1.17E-01 5.61E-02 5,313 2.19E-01 1.74E-01 1.07E-01 5.37E-02 5,621 2.08E-01 1.63E-01 9.86E-02 5.13E-02 5,946 1.96E-01 1.52E-01 9.03E-02 4.90E-02 6,290 1.85E-01 1.42E-01 8.24E-02 4.68E-02 6,655 1.75E-01 1.32E-01 7.51E-02 4.46E-02 7,040 1.64E-01 1.23E-01 6.83E-02 4.25E-02 7,448 1.54E-01 1.14E-01 6.19E-02 4.05E-02 7,879 1.45E-01 1.05E-01 5.61E-02 3.85E-02 8,335 1.35E-01 9.67E-02 5.07E-02 3.66E-02 8,818 1.27E-01 8.88E-02 4.59E-02 3.48E-02 9,329 1.18E-01 8.13E-02 4.15E-02 3.30E-02 9,869 1.10E-01 7.43E-02 3.76E-02 3.13E-02 10,440 1.02E-01 6.76E-02 3.41E-02 2.97E-02 11,045 9.42E-02 6.14E-02 3.10E-02 2.81E-02 11,685 8.70E-02 5.56E-02 2.84E-02 2.66E-02 12,361 8.02E-02 5.01E-02 2.61E-02 2.52E-02 13,077 7.37E-02 4.51E-02 2.42E-02 2.38E-02 13,834 6.76E-02 4.05E-02 2.26E-02 2.25E-02 14,636 6.19E-02 3.63E-02 2.13E-02 2.13E-02 15,483 5.65E-02 3.25E-02 2.01E-02 2.01E-02 16,380 5.15E-02 2.91E-02 1.90E-02 1.90E-02 17,328 4.69E-02 2.60E-02 1.80E-02 1.80E-02 A3-7
Appendix 3 Table A3-1. Tabular Data – Anomaly Distribution Curves (Figures A3-1 – A3-4) Billet #5 Billet #3 Billet #3 Billet #3 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Forging #3 Forging #3 Forging #2 Forging #1 FBH conv/ FBH conv/ FBH conv/ FBH conv/ Area exceedance exceedance exceedance exceedance sq mils per million lbs per million lbs per million lbs per million lbs 18,332 4.26E-02 2.33E-02 1.71E-02 1.71E-02 19,393 3.87E-02 2.10E-02 1.62E-02 1.62E-02 20,516 3.51E-02 1.89E-02 1.54E-02 1.54E-02 21,704 3.19E-02 1.72E-02 1.47E-02 1.47E-02 22,961 2.90E-02 1.57E-02 1.40E-02 1.40E-02 24,291 2.64E-02 1.45E-02 1.34E-02 1.34E-02 25,698 2.42E-02 1.36E-02 1.29E-02 1.29E-02 27,186 2.22E-02 1.28E-02 1.24E-02 1.24E-02 28,760 2.06E-02 1.22E-02 1.20E-02 1.20E-02 30,426 1.92E-02 1.17E-02 1.17E-02 1.17E-02 32,188 1.80E-02 1.14E-02 1.14E-02 1.14E-02 34,052 1.70E-02 1.11E-02 1.11E-02 1.11E-02 36,024 1.60E-02 1.09E-02 1.09E-02 1.09E-02 38,110 1.52E-02 1.06E-02 1.06E-02 1.06E-02 40,317 1.43E-02 1.04E-02 1.04E-02 1.04E-02 42,652 1.35E-02 1.01E-02 1.01E-02 1.01E-02 45,121 1.28E-02 9.89E-03 9.89E-03 9.89E-03 47,734 1.21E-02 9.66E-03 9.66E-03 9.66E-03 50,499 1.14E-02 9.44E-03 9.44E-03 9.44E-03 53,423 1.08E-02 9.22E-03 9.22E-03 9.22E-03 56,517 1.03E-02 9.00E-03 9.00E-03 9.00E-03 59,790 9.75E-03 8.79E-03 8.79E-03 8.79E-03 63,252 9.29E-03 8.58E-03 8.58E-03 8.58E-03 66,915 8.87E-03 8.38E-03 8.38E-03 8.38E-03 70,790 8.50E-03 8.18E-03 8.18E-03 8.18E-03 74,890 8.17E-03 7.99E-03 7.99E-03 7.99E-03 79,227 7.89E-03 7.80E-03 7.80E-03 7.80E-03 83,815 7.64E-03 7.61E-03 7.61E-03 7.61E-03 88,668 7.43E-03 7.43E-03 7.43E-03 7.43E-03 93,803 7.25E-03 7.25E-03 7.25E-03 7.25E-03 99,235 7.07E-03 7.07E-03 7.07E-03 7.07E-03 104,982 6.90E-03 6.90E-03 6.90E-03 6.90E-03 111,062 6.73E-03 6.73E-03 6.73E-03 6.73E-03 A3-8
Appendix 4 APPENDIX 4
DEFAULT POD APPLICABILITY
1. Use of Default POD Data
a. This Appendix defines conditions relevant to the use of accepted estimates of the probability of detection (POD) for specific types of anomalies and specific nondestructive evaluation/inspection techniques, which may be considered as default values when applied under appropriately similar conditions. The conditions defined in this Appendix do not necessarily guarantee the validity of these POD values. For example, if inspection parameters, such as penetrant concentration or temperature, are inadequately controlled, the penetrant capability shown in the accompanying graph will not be attained, even if the correct penetrant is selected. Use of a written plan for controlling and monitoring inspection processes is recommended (see paragraph 3 of this Appendix).
b. If the conditions described for each inspection are not satisfied, the resultant inspection capability and reliability will be reduced. Accordingly, the use of the default POD values would then be inappropriate and would result in an overly optimistic damage tolerance assessment.
2. Demonstrations of Inspection Capability
a. For ECI and ultrasonic inspection techniques, alternative default POD curves are given.
Choice of the appropriate POD curve must be based on demonstration that the stated calibration and reject signal levels are attainable on the component being inspected, and, for example, not prevented by noise or geometrical features. The demonstration conditions should be appropriate to the properties of the part inspected that may affect the inspectability, such as surface conditions, depth to be inspected, proximity to edges, etc. No other demonstration of these default capabilities is necessary, as long as the requirements for the specific inspection technique are satisfied (see paragraphs 3-6 of this Appendix).
b. It should be noted that, for specific inspection techniques applied under well controlled conditions, it may be possible to achieve POD values that are significantly better than the default POD values. Advantage may be taken of any such improved capability and reliability only if it is supported by a well documented demonstration A4-1
Appendix 4 program. Similarly, a well documented demonstration program may be necessary in order to measure POD values appropriate to specific conditions that are excluded from those the default values is supported by explicit, reasonable assumptions.
3. General Restrictions and Applicability
a. The inspection process must be well controlled, and performed in accordance with acceptable procedures, such as those defined by the engine standard practices manual, and consistent with good industrial inspection practices, such as those defined by MIL-STD’s, or equivalent industry standards.
b. Pertinent inspection process parameters such as coverage, probe indexing, and scanning speeds (see paragraph 4 of Section 3, and paragraphs 4-6 of this Appendix), should be governed by written procedures;. Inspection plans and any inspection fixturing, should be designed to minimize human and other sources of variability.
c. Inspectors must be fully qualified a nd trained for each NAS-410, ASNT-TC-1A, ATA-105, or equivalent, and provided with adequate training instructions in the specific inspection method.
d. The default POD data presented in this AC are applicable only to titanium alloys used for engine disks, and only to inspected material. Geometrical conditions, such as radii and edges can create areas where inspections can not be accomplished. Limitations also exist relative to depth of penetration and near surface resolution. Conditions under which the default POD data were acquired are outlined in paragraphs 4-6 of this Appendix; advice about the equivalence of alternative conditions should be sought from those with expertise in NDE. Areas of high compressive residual stress can have negative effects on the capability of various NDE techniques, most notably penetrant inspection.
e. Applicability of the default POD data is limited to components exhibiting no abnormal surface conditions, and that have been properly cleaned for each shop manual requirements. No other special pre-inspection cleaning or polishing is required.
A4-2
Appendix 4
4. Restrictions and Applicability: ECI
a. The ECI is an inspection technique suitable for the detection of surface or near-surface anomalies. For the purposes of this document, it is intended primarily for application to engine-run components. The default POD data were acquired under the following conditions:
(1) Probes containing absolute coils, with inspection frequency in the range 2-6 MHz.
(2) Probe fixturing capable of following surface contours of the component being inspected, with adequate control of attitude, lift-off and scan indexing. The scan direction was parallel with any uniform feature changes.
(3) Provision was made for automatic recording of the inspection process signals or automated alarm, or both, when the inspection threshold is exceeded.
b. The default POD data apply to surface-connected low-cycle fatigue cracks. Cracks are assumed to have a 2-to-1 aspect (length:depth) ratio. Crack sizes are expressed in terms of the length at the surface. Cracks must not be obscured by oxide, contaminants, etc. Inspected surfaces should be flat, or only moderately curved. Choice of the appropriate POD curve from those provided must be based on component demonstration of the attainable inspection sensitivity (see paragraph 2 of this Appendix).
5. Restrictions and Applicability: Penetrant Inspection (PT/FPI)
a. PT is an inspection technique suitable for the detection of anomalies that are open to the inspected surface. For the purposes of this document, it is intended primarily for application to engine-run components. The default POD data were acquired under the following conditions:
(1) Fluorescent penetrants qualified as level 4 by AMS-2644 or equivalent, and used with dry powder developer (as a minimum).
(2) Application of penetrant and developer was automated, or for each standard practices; (see, for example, ASTM E 1417 and AMS-2647).
A4-3