Definition
Maximum Elevation Figures (MEFs) are numbers printed within each quadrangle on a VFR sectional chart that represent the highest known elevation of any terrain feature or obstacle within that quadrangle, rounded up and with a buffer added for safety. They give pilots a quick reference for the minimum altitude needed to clear everything inside that section of the chart.
Plain English
MEFs are numbers shown on a VFR sectional chart that tell you the highest point — terrain or obstacle — inside each box on the chart, so you know how high you need to fly to be safely above everything in that area.
Context Anchor
Seen on VFR charts during preflight planning, especially when checking terrain, towers, and safe altitude choices along a route.
Derivation
From 'maximum' (Latin maximus, greatest) + 'elevation' (Latin elevare, to raise up — here meaning height above sea level) + 'figure' (the number printed on the chart). The name describes exactly what it is: the largest height number for that area.
Why Pilots Care
MEFs give pilots a quick, conservative number to ensure safe terrain clearance under visual flight rules.
Intuition Check
MEFs are not assigned flying altitudes and they do not guarantee clearance by themselves. They are charted warning numbers that help you notice the highest known terrain or obstacle in that area.
Example Sentence 1
Before crossing the ridge, the pilot checked the MEFs along the route and chose a cruising altitude well above the highest one shown.
Example Sentence 2
With an MEF of 3,800 feet in the quadrant, we flew at 5,500 feet to maintain clearance.