What are the vertical limits of a transition area designated with an airport having a prescribed IAP?

The correct answer reflects the established criteria for the vertical limits of a transition area associated with instrument approach procedures (IAP) at airports. Transition areas are designed to provide additional protection for aircraft conducting approaches to an airport and typically extend from a specified altitude up to a higher defined limit.

In this context, 700 feet above ground level (AGL) to the base of controlled airspace is the standard vertical limit for a transition area surrounding an airport. This range is established to ensure that aircraft transitioning to an instrument approach can operate safely and efficiently without interference from surrounding airspace that may be used by other aircraft.

Understanding this limit is crucial for pilots, as it helps them maintain awareness of their positional relationship to controlled airspace and ensures compliance with air traffic control (ATC) instructions while executing approach and landing maneuvers. The selected altitude provides an appropriate buffer, maintaining safety while also facilitating the efficient management of both instrumental and visual flight operations.

This particular answer aligns with regulatory guidelines that define how transition areas must be structured, thereby supporting safe and orderly traffic flow in complex airspace configurations around airports.