The Air Carrier Activity Information System (ACAIS) is a system used by the Federal Aviation Administration (FAA) to collect and process data on the activities of air carriers, including airlines, in the United States. The system is designed to provide a comprehensive picture of air carrier operations, including flight schedules, passenger and cargo traffic, and other operational data.

ACAIS collects data from air carriers on a monthly basis, and the information is used to support a wide range of aviation-related activities, including:

1. Aviation planning and policy development: ACAIS data is used to inform decisions on aviation infrastructure development, air traffic management, and safety initiatives.
2. Economic analysis: The data is used to analyze the economic impact of aviation on local and national economies.
3. Safety analysis: ACAIS data is used to identify trends and patterns in aviation safety, and to support the development of safety initiatives.
4. Environmental analysis: The data is used to estimate the environmental impact of aviation, including greenhouse gas emissions and noise pollution.
5. Airport planning: ACAIS data is used to support airport planning and development, including the analysis of passenger and cargo traffic, and the development of airport master plans.

The types of data collected by ACAIS include:

1. Flight schedules and operations
2. Passenger and cargo traffic
3. Aircraft utilization and availability
4. Crew and personnel data
5. Financial data, including revenue and expenses
6. Safety data, including incident and accident reports

The ACAIS system is an important tool for the FAA and other stakeholders in the aviation industry, as it provides a comprehensive and timely picture of air carrier operations and trends. The data is used to support decision-making, policy development, and safety initiatives, and to promote the safe and efficient operation of the national air transportation system.