How is the decision made regarding the Minimum Altitude Point (MAP) during a non-precision approach without a DME?

The Minimum Altitude Point (MAP) during a non-precision approach without a Distance Measuring Equipment (DME) is determined using the timing method chart on the approach plate. This method relies on the time taken from a certain point in the approach, such as the Final Approach Fix (FAF), to estimate the descent to the MAP. The procedure is crafted to account for the aircraft's groundspeed and the expected flying time to reach the MAP, allowing pilots to maintain safe altitude and position throughout the approach.

In contrast to visual inspection of landmarks, which can be subjective and dependent on visibility conditions, the timing method integrates standardized flight procedures and a clear understanding of the aircraft's performance characteristics. While relying on instruments alone might provide certain altitude readings, it does not convey the necessary information about distance to the MAP when DME is not available. Following GPS indications can also assist in navigation, but its reliability can vary and does not encompass the standardized approach criteria established for non-precision approaches without DME. Therefore, the timing method chart offers a systematic approach to ensure safety during the critical phase of landing.