Missed approach point
(MAPt or MAP) is the "point prescribed in each instrument approach
at which a missed approach procedure shall be executed if the required visual reference does not exist." It defines the point for precision
approaches when the missed approach segment of a flight begins provided the runway environment is not in sight. A pilot must execute a missed approach
if a required visual reference (normally the runway or its environment) is not in sight or the pilot decides it is unsafe to continue with the approach and landing to the runway
. The missed approach point is published in the approach plates and contains instructions for missed approach procedures to be executed at this point. The missed approach point is normally at the Minimum Descent Altitude (MDA)
, and may be less than a mile from the runway or several miles out, depending on the conditions related to that particular runway.
The MAP is similar in principle to the Decision Height Point, in that the pilot in command must make a clear and unequivocal Yes/No decision upon arrival at this point - either the runway (or its specified environment) is positively visible and accessible for landing using a safe and stabilized approach (i.e. no excessively steep bank or descent angles required), in which case the approach to landing may be continued, or else the approach must be discontinued and the published missed approach procedure must be initiated immediately.
Visual descent point
A concept related to the missed approach point is the Visual Descent Point
, or VDP. This is a point on the MDA of a non-precision approach profile, from where the aircraft would be able to continue its descent to the runway threshold while maintaining a standard 3 degree descent angle. The concept of VDP was developed by the FAA
to allow pilots to decide to initiate a missed approach
even prior to reaching the MAP, in a situation where the runway or its environment is not visible at a 'normal' descent angle. Conversely, if the runway is visible at the VDP, the pilot may continue, following a standard descent angle to the runway. The VDP is always farther from the runway threshold than the MAP.
The following is the U.S. FAA's official definition of VDP:
"A defined point on the final approach course of a nonprecision straight-in approach procedure from which normal descent from the MDA to the runway touchdown point may be commenced, provided the approach threshold of that runway, or approach lights, or other markings identifiable with the approach end of that runway are clearly visible to the pilot.