During an approach, what is the usual altitude choice for the initial approach fix?

The initial approach fix (IAF) altitude is crucial in ensuring that aircraft can safely transition from enroute to approach phases of flight while remaining within controlled airspace and avoiding terrain. The choice of altitude allows for a standardized altitude for the approach procedure, ensuring that air traffic control can manage separation between aircraft and allow for a stable descent.

In this scenario, an altitude of Flight Level (FL) 210 is typically chosen for the initial approach fix. This altitude provides sufficient vertical separation from enroute traffic and offers a practical margin for descent onto the final approach path.

Choosing this altitude allows pilots to maintain safe flight operations while aligning with standard terminal arrival routes and approach procedures. It also reflects the common practices and regulatory guidelines established within the aviation industry for effective spacing and separation, especially in busy airspace environments.

Other altitudes listed, such as FL 200, FL 250, and FL 300, while they could theoretically serve as IAF altitudes in specific circumstances, do not align with typical procedures and requirements that favor a standardized approach to minimize complexity and enhance safety.