This legislation, titled the Rotorcraft Operations Transparency and Oversight Reform Act (ROTOR Act), seeks to significantly improve aviation safety by requiring most aircraft to be equipped with Automatic Dependent Surveillance-Broadcast In (ADS-B In) technology. It also introduces stricter regulations for existing ADS-B Out exceptions, particularly for government and military flights, and mandates comprehensive safety reviews of airspace. A key provision of the bill is the requirement for the Federal Aviation Administration (FAA) to issue a final rule within two years, mandating that all aircraft already equipped with ADS-B Out must also be equipped with and operating ADS-B In by December 31, 2031 . This ADS-B In equipment must provide pilots with enhanced situational awareness of other aircraft and traffic advisories. The FAA is tasked with establishing performance standards for this equipment, including considering low-cost alternatives for smaller aircraft. The bill also reforms exceptions for ADS-B Out transmissions, narrowly construing the term "sensitive government mission" to exclude training or proficiency flights and flights by Federal officials below Cabinet Member rank. The FAA must update regulations and agreements within one year to reflect these changes, with reporting requirements to Congress if deadlines are missed. The Government Accountability Office (GAO) will review the utilization of these exceptions before and after the regulatory changes, and the FAA must address any non-compliant operators. To ensure transparency and compliance, Federal, State, local, and Tribal agencies performing sensitive government missions must submit quarterly reports to the FAA, detailing operations where ADS-B Out was not in transmit mode. The FAA will then biannually report to Congress on the frequency and nature of these exceptions, including a determination of whether such operations jeopardize aviation safety. Annual audits by the Department of Transportation's Inspector General will assess FAA oversight of these exceptions. The legislation also establishes an Office of FAA-DOD Coordination to manage airspace usage and improve safety information sharing between civil and military aviation. This office will conduct safety reviews of military, law enforcement, and civilian flight operations in the Washington DC Metropolitan Area Special Flight Rules Area and other Class B, C, and D airports. These reviews will evaluate risks to commercial transport airplane operations and assess air traffic management and coordination levels. Furthermore, the bill mandates that the FAA enter into Memoranda of Understanding (MOUs) with the Department of the Army, Navy, Air Force, and the Coast Guard to facilitate the sharing of aviation safety information. This aims to improve communication and analysis of impacts on civil aviation safety and efficiency. The bill also repeals a previous provision regarding ADS-B equipment on certain Department of Defense aircraft. The Inspector General of the Army is required to conduct an audit evaluating the Army's coordination with the FAA, pilot training, and adherence to ADS-B Out policies, particularly in the National Capital Region. The results of this audit, including any findings on maintenance protocols for specific aircraft and compliance with existing agreements, must be publicly disclosed to Congress without redactions, except for national security reasons. Finally, the bill requires the FAA to develop an action plan for advancing the deployment of the Airborne Collision Avoidance System-X (ACAS-X) technology, including a strategic roadmap and engagement with stakeholders. The Aviation Rulemaking Advisory Committee (ARAC) will also review the need for ADS-B Out and ADS-B In equipment in Class D airspace, providing recommendations to the Administrator and Congress.