What is the required timeframe for starting and completing a FDME or FDHS?

The timeframe for starting and completing a Flight Duty Medical Examination (FDME) or Flight Duty Health Surveillance (FDHS) is crucial for maintaining valid medical certification for pilots. The correct timeframe is three months preceding the birth month. This specific period ensures that the medical evaluation reflects the most current health status of the individual, taking into account any potential changes in medical conditions or fitness to fly that may occur over time.

This three-month window allows the medical examiner to evaluate any recent health issues, medication changes, or lifestyle factors that could impact the pilot's ability to operate an aircraft safely. By requiring the examination within this timeframe, aviation authorities can ensure that the information regarding a pilot's medical fitness is as accurate and relevant as possible, thereby enhancing safety in aviation operations.

The other options suggest varying windows that do not align with the regulatory requirements established for ensuring pilot health and safety. For example, the suggestion of one month or six months would not account for fluctuations in an individual's health that could occur. Similarly, an extended timeframe of one year could lead to outdated evaluations, compromising the medical oversight essential for safe flying operations. Thus, the three-month period preceding the birth month is the most appropriate and regulatory correct choice for timely assessments.