Definition
Maximum Elevation Figures (MEFs) are values printed in each quadrangle on VFR sectional and terminal area charts that represent the highest elevation within that quadrangle, including terrain and the highest known obstruction (such as towers, antennas, or buildings), rounded up with a buffer to account for vertical accuracy and unknown obstacles. The figure is shown in thousands and hundreds of feet above mean sea level (MSL).
Plain English
A number on a sectional chart that tells you the highest thing — ground or man-made structure — inside that square of the map, so you know the lowest altitude that would clear everything in it.
Context Anchor
Seen on VFR charts when planning a route and checking terrain or obstacle height along the way.
Derivation
“Maximum” means the greatest, and “elevation” means height above sea level. The term is literal: the largest height figure for that section of the chart.
Why Pilots Care
Allows pilots to select a safe cruising altitude above all possible obstacles in the area.
Grounding Statement
If a chart block has an MEF of 4,800 feet, plan as though something known in that block may reach close to that height above sea level.
Intuition Check
Do not read “maximum” as “safe altitude.” An MEF is a rounded-up highest-known-height number for a chart block, not a required or recommended altitude to fly.
Example Sentence 1
Before crossing the ridge, she checked the MEFs along her route and chose a cruising altitude 1,000 feet above the highest one.
Example Sentence 2
MEFs help ensure terrain clearance during VFR cross-country flights.