Final answer:
Any aircraft with a seating capacity of 10 or more is required to have a functioning Flight Data Recorder (FDR) for accident investigation and improving aviation safety.
Step-by-step explanation:
In the United States, Any aircraft with a seating capacity of 10 or more is required to have a functioning Flight Data Recorder (FDR). An FDR is a device that records various parameters of an aircraft's flight data, such as altitude, airspeed, and heading. It is used for accident investigation and improving aviation safety. The requirement for FDRs applies to all aircraft regardless of their manufacture date. For example, a commuter aircraft with 30 seats would be required to have a functioning FDR.