Minimum Safe Altitude - FAA Definition - VFR Flights

VFR Flights

Since VFR flights are not necessarily conducted on straight lines between ground-based radio navigation transmitters, the altitude restrictions for IFR flights (above) are not applicable. Instead, a VFR flight can be conducted using pilotage, watching landmarks to determine position and desired direction. In this situation, the minimum reception altitude becomes moot, and the over-riding concern is for obstacle clearance.

Pilotage in the United States is usually accomplished with the use of sectional charts, which show the ground with considerable accuracy, both for terrain levels and for man-made objects. The charts are marked with Georef grids, and at the center of each grid square a number shows the elevation (MSL) of the highest obstacle within that grid (the Maximum Elevation Figure or MEF). Thus a pilot is alerted of how high he must fly while traversing that grid to assure clearance of all possible obstacles. Then it is up to the pilot to select a cruising altitude which will provide the required clearance above those obstacles.

On sectional charts, man-made obstacles less than 200 feet in height may not be shown.