The Federal Aviation Administration (FAA) Office of Accident Investigation is responsible for investigating accidents and incidents involving aircraft, as well as other aviation-related events. The office is a part of the FAA's Aviation Safety organization and plays a critical role in promoting aviation safety.

The primary goal of the FAA Office of Accident Investigation is to determine the cause of accidents and incidents, and to identify factors that contribute to them. The office uses this information to develop safety recommendations and to implement changes to regulations, policies, and procedures that will help prevent similar accidents and incidents from occurring in the future.

The FAA Office of Accident Investigation has several key responsibilities, including:

1. Investigating accidents and incidents: The office investigates accidents and incidents involving aircraft, such as crashes, engine failures, and other safety-related events.
2. Determining probable cause: The office determines the probable cause of each accident or incident, which involves identifying the underlying factors that contributed to the event.
3. Developing safety recommendations: Based on the findings of each investigation, the office develops safety recommendations that are intended to prevent similar accidents and incidents from occurring in the future.
4. Implementing safety changes: The office works with other FAA offices, as well as with the aviation industry and other stakeholders, to implement safety changes and to ensure that safety recommendations are implemented.
5. Analyzing data: The office analyzes data on accidents and incidents to identify trends and patterns, and to develop strategies for reducing the risk of accidents and incidents.

The FAA Office of Accident Investigation uses a variety of methods to investigate accidents and incidents, including:

1. On-site investigations: The office sends investigators to the scene of an accident or incident to collect data and evidence.
2. Interviews: The office conducts interviews with witnesses, pilots, and other individuals who may have information about the accident or incident.
3. Data analysis: The office analyzes data from a variety of sources, including flight data recorders, cockpit voice recorders, and other aircraft systems.
4. Laboratory testing: The office may conduct laboratory testing of aircraft components and other materials to help determine the cause of an accident or incident.

Overall, the FAA Office of Accident Investigation plays a critical role in promoting aviation safety by identifying the causes of accidents and incidents, and by developing and implementing safety recommendations to prevent similar events from occurring in the future.