Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA A1-1. What flight and ground load spectra are presented in this appendix?
The following list summarizes the flight and ground load spectra presented in this appendix.
Flight Spectra, General Usage, Single-Engine Unpressurized Description Graphic Data Tabulated Data Comments Gust spectra for single-engine, unpressurized operations, including basic instruction, personal, executive, and acrobatic usage.
Figure A1-1 Table A1-1 These spectra should also be used for pressurized single-engine airplanes that spend a significant amount of flight time at low altitudes.
Maneuver spectra for singleengine basic instruction usage.
Figure A1-2 Table A1-2 Maneuver spectra for singleengine personal usage.
Figure A1-3 Table A1-3 An airplane in the personal usage category has a single, reciprocating engine with 185 horsepower or less.
Maneuver spectra for singleengine executive usage.
Figure A1-4 Table A1-4 An airplane in the executive usage category has a single, reciprocating engine with more than 185 horsepower. The executive usage category also includes unpressurized, singleengine turboprop airplanes.
Maneuver spectra for singleengine acrobatic usage.
Figure A1-5 Table A1-5 Applicable to typical acrobatic category airplanes, nz = +6g / -3g Flight Spectra, General Usage, Twin-Engine Unpressurized Description Graphic Data Tabulated Data Comments Gust spectra for twin-engine, unpressurized operations, including instruction, and general usage.
Figure A1-6 Table A1-6 These spectra should also be used for pressurized twin-engine airplanes that may spend a significant amount of flight time at low altitudes, 7,000 feet and below. An example of this type of operation is short flight duration commuter and air taxi operations.
Maneuver spectra for twinengine instruction usage.
Figure A1-7 Table A1-7 Maneuver spectra for twinengine general usage.
Figure A1-8 Table A1-8 These spectra should also be used for pressurized and unpressurized twin-engine airplanes that may be operated in short flight duration commuter and air taxi operations.
A1-1
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Flight Spectra, General Usage, Single-Engine and Twin-Engine Pressurized Description Graphic Data Tabulated Data Comments Gust spectra for pressurized usage.
Figure A1-9 Table A1-9 Maneuver spectra for pressurized usage.
Figure A1-10 Table A1-10 Flight Spectra, Special Usage – Agricultural (Aerial Application) Description Graphic Data Tabulated Data Comments Gust spectra for agricultural or aerial application usage.
Figure A1-11 Table A1-11 Maneuver spectra for agricultural or aerial application usage.
Figure A1-12 Table A1-12 Flight Spectra, Special Usage – Survey (Pipeline Patrol) Description Graphic Data Tabulated Data Comments Gust spectra for low-level survey or pipeline patrol usage.
Figure A1-13 Table A1-13 Maneuver spectra for lowlevel survey or pipeline patrol usage.
Figure A1-14 Table A1-14 Ground Spectra Description Graphic Data Tabulated Data Comments Landing Impact Figure A1-15 Taxi Figure A1-16 A1-2
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED) A1-2. How do I compute the gu st limit load factor used in the gust load spectra?
a. The equation for computing the gust load limit load factor has evolved through the regulatory history of the Civil Air Regulation Part 3 (CAR 3) and 14 CFR Part 23. These changes to the gust load formula incorporate the improving knowledge of airplane response to atmospheric turbulence. The gust load spectra presented in this AC are normalized to the gust load formula in use before Amendment 23-7 to 14 CFR Part 23. Regardless of the certification basis of your airplane, you must calculate a gust load limit load factor (for use in developing fatigue loading spectra only) using the same equation used to derive the gust spectra.
b. Formula for computing the incremental gust load limit load factor:
U K V m anLLF = W498 S where U = 30.0, nominal gust velocity in feet per second 1 1 ⎛ 4 for W/S < 16 lbs / ft2K = ⎟ ⎠ ⎞⎜ ⎝ W S2
2.67 for W/S > 16 lbs / ft2= 1.33
⎛⎜ ⎝ − 3 W ⎞⎟ ⎠ 4 S
W / S = Wing loading at maximum weight, lbs / ft 2 V = Airplane structural design cruise speed, VC, KEAS m = Wing lift curve slope, C Lα, rad-1 A1-3. How are gust and maneuver load spectra ‘normalized’?
a. We normalized the gust spectra to the incremental gust limit load factor computed in Paragraph A1-2. We expressed the gust spectra in terms of the gust load factor ratio:
an = IncrementalGustLoad Factorat OperatingWeight anLLF IncrementalDesignLimitGustLoad FactoratMaximumGrossWeight
b. We normalized the maneuver spectra to the incremental maneuver limit load factor.
We expressed the maneuver spectra in terms of the maneuver load factor ratio:
an = IncrementalManeuverLoad Factorat OperatingWeight anLLF IncrementalDesignLimitManeuverLoad FactoratMaximumGrossWeight A1-3
Acceleration Fraction, an / anLLF Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Cumulative Frequency of Exceedance per Nautical Mile 100
10-1
10-2
10-3
10-4
10-5
10-6
Figure A1-1 Gust Spectra For Single-Engine Unpressurized Operations Including Basic Instruction, Personal, Executive, and Acrobatic Usage See Table A1-1 for Tabulated Spectra 8
1.5
1.0 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 A1-4
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Table A1-1 Gust Spectra For Single-Engine Unpressurized Operations Including Basic Instruction, Personal, Executive, and Acrobatic Usage Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile
0.10 7.99040E-01 -0.10 8.86903E-01
0.15 2.39762E-01 -0.15 2.90400E-01
0.20 8.26537E-02 -0.20 7.93185E-02
0.25 2.59957E-02 -0.25 2.50615E-02
0.30 9.43467E-03 -0.30 8.64457E-03
0.35 3.74392E-03 -0.35 3.13716E-03
0.40 1.56672E-03 -0.40 1.17560E-03
0.45 6.76810E-04 -0.45 4.49619E-04
0.50 2.96910E-04 -0.50 1.74053E-04
0.55 1.31101E-04 -0.55 6.77344E-05
0.60 5.79043E-05 -0.60 2.63806E-05
0.65 2.55611E-05 -0.65 1.02760E-05
0.70 1.12764E-05 -0.70 4.00187E-06
0.75 4.97072E-06 -0.75 1.55782E-06
0.80 2.18708E-06 -0.80 6.05622E-07
0.85 9.58226E-07 -0.85 2.34685E-07
0.90 4.15769E-07 -0.90 9.01733E-08
0.95 1.76305E-07 -0.95 3.38733E-08
1.00 7.05919E-08 -1.00 1.19395E-08 A1-5
Acceleration Fraction, an / anLLF Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Cumulative Frequency of Exceedance per Nautical Mile 100
10-1
10-2
10-3
10-4
10-5
10-6
Figure A1-2 Maneuver Spectra For Single-Engine Basic Instruction Usage See Table A1-2 for Tabulated Spectra 8
1.5
1.0 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 A1-6
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Table A1-2 Maneuver Spectra For Single-Engine Basic Instruction Usage Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile
0.10 2.37466E-01 -0.10 2.22202E-01
0.15 1.20023E-01 -0.15 7.79188E-02
0.20 6.20605E-02 -0.20 2.89635E-02
0.25 3.45611E-02 -0.25 1.18361E-02
0.30 1.99278E-02 -0.30 4.73564E-03
0.35 1.16586E-02 -0.35 1.81743E-03
0.40 6.84325E-03 -0.40 6.69379E-04
0.45 4.01154E-03 -0.45 2.39525E-04
0.50 2.34706E-03 -0.50 8.45918E-05
0.55 1.36820E-03 -0.55 2.98155E-05
0.60 7.93694E-04 -0.60 1.04723E-05
0.65 4.59287E-04 -0.65 3.66958E-06
0.70 2.65584E-04 -0.70 1.28565E-06
0.75 1.53197E-04 -0.75 4.50315E-07
0.80 8.79528E-05 -0.80 1.57610E-07
0.85 5.01008E-05 -0.85 5.50454E-08
0.90 2.81951E-05 -0.90 1.91064E-08
0.95 1.55016E-05 -0.95 6.51330E-09
1.00 8.15702E-06 -1.00 2.10063E-09 A1-7
Acceleration Fraction, an / anLLF Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Cumulative Frequency of Exceedance per Nautical Mile 100
10-1
10-2
10-3
10-4
10-5
10-6
Figure A1-3 Maneuver Spectra For Single-Engine Personal Usage See Table A1-3 for Tabulated Spectra 8
1.5
1.0 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 A1-8
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Table A1-3 Maneuver Spectra For Single-Engine Personal Usage Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile
0.10 1.28156E-01 -0.10 9.71117E-02
0.15 6.27614E-02 -0.15 3.13880E-02
0.20 3.09500E-02 -0.20 1.09533E-02
0.25 1.58120E-02 -0.25 4.71523E-03
0.30 8.12433E-03 -0.30 2.07230E-03
0.35 4.12127E-03 -0.35 8.91311E-04
0.40 2.04241E-03 -0.40 3.75403E-04
0.45 9.97803E-04 -0.45 1.55129E-04
0.50 4.83819E-04 -0.50 6.29010E-05
0.55 2.33291E-04 -0.55 2.50877E-05
0.60 1.12320E-04 -0.60 9.84679E-06
0.65 5.40555E-05 -0.65 3.80374E-06
0.70 2.59889E-05 -0.70 1.44615E-06
0.75 1.24766E-05 -0.75 5.41094E-07
0.80 5.97051E-06 -0.80 1.99191E-07
0.85 2.83754E-06 -0.85 7.20825E-08
0.90 1.32888E-06 -0.90 2.55778E-08
0.95 6.02384E-07 -0.95 8.83264E-09
1.00 2.52545E-07 -1.00 2.89847E-09 A1-9
Acceleration Fraction, an / anLLF Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Cumulative Frequency of Exceedance per Nautical Mile 100
10-1
10-2
10-3
10-4
10-5
10-6
Figure A1-4 Maneuver Spectra For Single-Engine Executive Usage See Table A1-4 for Tabulated Spectra 8
1.5
1.0 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 A1-10
Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Table A1-4 Maneuver Spectra For Single-Engine Executive Usage Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile Acceleration Fraction Cumulative Frequency of Exceedance per Nautical Mile
0.10 5.10093E-02 -0.10 5.54495E-02
0.15 1.97508E-02 -0.15 1.88747E-02
0.20 7.38092E-03 -0.20 6.05428E-03
0.25 3.13527E-03 -0.25 2.32888E-03
0.30 1.40483E-03 -0.30 9.20494E-04
0.35 6.60426E-04 -0.35 3.59308E-04
0.40 3.12393E-04 -0.40 1.35529E-04
0.45 1.48798E-04 -0.45 4.99636E-05
0.50 7.13657E-05 -0.50 1.81837E-05
0.55 3.43582E-05 -0.55 6.53422E-06
0.60 1.65390E-05 -0.60 2.31853E-06
0.65 7.96002E-06 -0.65 8.12393E-07
0.70 3.82975E-06 -0.70 2.81096E-07
0.75 1.84127E-06 -0.75 9.60362E-08
0.80 8.83928E-07 -0.80 3.23840E-08
0.85 4.23025E-07 -0.85 1.07639E-08
0.90 2.01127E-07 -0.90 3.51182E-09
0.95 9.42952E-08 -0.95 1.10946E-09
1.00 4.28623E-08 -1.00 3.23514E-10 A1-11
Acceleration Fraction, an / anLLF Appendix 1 APPENDIX 1. FLIGHT AND GROUND LOAD SPECTRA (CONTINUED)
Cumulative Frequency of Exceedance per Flight Hour 105 104 103 102 101 100 10-1 Figure A1-5 Maneuver Spectra For Single-Engine Acrobatic Usage See Table A1-5 for Tabulated Spectra 8 6 5 4 3 2
1.5
1.0 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 A1-12