FAA AC 23-13 : 2005

1 What is the purpose of this AC?
2 What is incorporated in this AC and, thereby, superseded?
3 What is the background for this AC and what time period
     does this AC cover?
4 How should the information contained in this AC be applied?
5 What regulations are discussed in this AC?
6 What other publications are related to this AC?
7 What are the definitions for the common terms used in this
     AC?
CHAPTER 1 SMALL AIRPLANE FATIGUE REGULATIONS
1-1 What is the goal of the small airplane fatigue requirements?
1-2 How have the fatigue requirements changed over time?
1-3 Can you summarize the current fatigue regulations for small
     airplanes?
1-4 Which metallic components should I include in the fatigue
     evaluation?
1-5 Are the small airplane fatigue regulations different in
     other countries?
1-6 How do I show compliance to the fatigue requirements for
     alterations, modifications, or changes to the design?
CHAPTER 2 SAFE-LIFE FATIGUE EVALUATION
2-1 What is a safe-life fatigue evaluation?
2-2 What is the definition of failure in a safe-life
     structure?
2-3 What are the steps in evaluating the safe-life of a
     structure?
2-4 What loading spectra should I use?
2-5 How were the load spectra in Appendix 1 developed?
2-6 Can I use other loading spectra in place of the Appendix
     1 spectra?
2-7 What should I consider in developing a mission profile?
2-8 Does the FAA require a flight test to validate the loads
     I use in my fatigue evaluation?
2-9 Does the FAA require validation of the stresses I use
     in my fatigue evaluation?
2-10 How do I substantiate a fatigue safe-life with
     full-scale fatigue tests?
2-11 What should I include in the test plan for my full-scale
     fatigue tests?
2-12 Do I need to complete the test before the FAA will issue
     the type certificate (TC)?
2-13 How do I calculate the fatigue safe-life using full-scale
     fatigue test results?
2-14 How do I calculate the mean test life?
2-15 What are the scatter factors for full-scale fatigue tests?
2-16 What about statistical confidence intervals on full-scale
     fatigue test results?
2-17 What counts as one test specimen, and what counts as two
     test specimens?
2-18 Can I use a full-scale test scatter factor lower than that
     obtained from Equation 4?
2-19 What about the '3-sigma' method of computing the safe-life?
2-20 How do you substantiate a fatigue safe-life with component
     tests?
2-21 What loads do I apply in a component test?
2-22 For component testing, how many specimens do I need to test?
2-23 For component testing, what scatter factor should I use?
2-24 How do you substantiate a fatigue safe-life with analysis
     supported by test evidence?
2-25 What are some concerns with substantiation by fatigue
     analysis?
2-26 What scatter factors do I use in a fatigue analysis?
2-27 How can I extend the safe-life, or retirement life,
     of my airplane?
CHAPTER 3 FAIL-SAFE DESIGN
3-1 What is a fail-safe design?
3-2 What is the history of fail-safe design?
3-3 How can I assure that my design complies with the
     fail-safe design requirements?
3-4 What are some design considerations in achieving a
     fail-safe design?
3-5 What is a Principal Structural Element?
3-6 How much fatigue damage should I consider in my
     fail-safe evaluation?
3-7 How do I address inaccessible areas?
3-8 How do I account for dynamic effects?
3-9 How do I test principal structural elements?
3-10 Can I use analysis to substantiate a fail-safe design?
3-11 How do I select the critical areas?
CHAPTER 4 DAMAGE TOLERANCE EVALUATION
4-1 Are there any differences between the part 23 and part
     25 damage tolerance regulations?
CHAPTER 5 ROTORBURST REQUIREMENTS
5-1 What are the requirements for turbine or turbopropeller
     installations in small airplanes?
5-2 I thought there was not a discrete source damage
     requirement in part 23?
CHAPTER 6 FLIGHT WITH KNOWN CRACKS
6-1 What is the purpose of this policy?
6-2 What is the policy for operational flight with known
     cracks?
6-3 Are there any exceptions to this policy?
6-4 Which airplanes are covered by this policy?
6-5 What will the FAA consider before allowing operational
     flight with known cracks?
REFERENCES
APPENDIX 1 FLIGHT AND GROUND LOAD SPECTRA
APPENDIX 2 S/N CURVES FOR ALUMINUM COMPONENTS

Provides information and guidance concerning acceptable means, but not the only means, of compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 23. Applicable to fatigue, fail-safe, and damage tolerance evaluations of metallic structure in normal, utility, acrobatic, and commuter category airplanes.