While there is a limited data on safety-sensitive professionals, substance use disorders potentially affect pilots and flight attendants at the same rate as the general population - around 15 percent - but due to the high-risk nature of their jobs, aircraft operators are held to a higher standard for substance misuse on the job. To protect the safety of the public and the aviation workforce, the Human Intervention Motivation Study (HIMS) and the Flight Attendant Drug and Alcohol Program (FADAP) were launched to help treat critical aviation workers - pilots and flight attendants, respectively - who misuse substances. In response to a congressional mandate, this new report reviews available evidence on the effectiveness of HIMS and FADAP and offers recommendations for improving these programs. Table of Contents Front Matter Summary 1 Introduction 2 Brief Descriptions of the Human Intervention and Motivational Study and the Flight Attendant Drug and Alcohol Program 3 Evidence-Based Practices for Identifying and Treating Substance Use Disorders 4 A Program Evaluation Overview for Support of Pilots and Flight Attendants with Substance Use Disorders 5 Outcomes of the Human Intervention and Motivational Study and the Flight Attendant Drug and Alcohol Program: Analysis of the Available Evidence 6 Summary Assessment: Conclusions and Recommendations References Appendix A: Other Alcohol and Drug Programs in the Transportation Sector Appendix B: Speakers, Papers, and Literature Review - Data Gathering Appendix C: Communications Between the Committee and the Federal Aviation Administration, Human Intervention and Motivational Study, Airline Pilots Association, International, and Congressional Staff Appendix D: Committee Member Biosketches Appendix E: Disclosure of Unavoidable Conflict of Interest