What is one of the required pilot documents according to FAR 61.3?

One of the required pilot documents according to FAR 61.3 is an appropriate pilot certificate. This certificate proves that the pilot has met the necessary training and competency requirements set by the Federal Aviation Administration (FAA) to operate an aircraft. The pilot certificate also indicates the specific class and type of aircraft that the pilot is authorized to fly, which is crucial for ensuring safety and compliance with aviation regulations.

The other options do not fulfill the requirements outlined in FAR 61.3. A government-issued birth certificate is not a credential specifically related to flying, and while it may be used for identity verification in various contexts, it does not serve as proof of a pilot's qualifications. A medical insurance card is unrelated to pilot certification; it addresses healthcare coverage rather than the pilot's ability to fly. Similarly, a training course completion certificate, while it may be part of the journey toward obtaining a pilot certificate, does not itself grant the authority to operate an aircraft. Only the appropriate pilot certificate satisfies the regulatory requirements established by the FAA.