Review the FAAs regulations (FARs) regarding duty day limits forFAR Part 121, Part 135, and Part 91 flight operations(Links to an external site.). Next, analyze and evaluate the differences in the regulations between Parts by creatively applying the concepts of human performance and limitations that you learned in this module. Finally, develop and support your opinion as to whether the differences in the regulations are justified in regard to maintaining aviation safety. As always, support your work with a reliable source(s).