Definition
A leveling-off technique in which the pilot begins the transition from a climb or descent to level flight 100 feet before reaching the target altitude. During a climb, the pilot starts lowering the pitch attitude 100 feet below the target altitude; during a descent, the pilot starts raising the pitch attitude 100 feet above the target altitude. The 100-foot value is a rule of thumb suited to typical training-aircraft vertical speeds of around 500 feet per minute.
Plain English
Don't wait until you're exactly at your target altitude to level off — start the level-off 100 feet early so the airplane settles smoothly onto the altitude instead of overshooting.
Context Anchor
Used during instrument flying when transitioning from a climb or descent to level flight at a selected altitude.
Derivation
Here, “lead” comes from the idea of going before or acting ahead of something. In flying, to lead an altitude means to begin the needed control change before reaching that altitude, not after.
Why Pilots Care
Prevents altitude overshoots that can violate assigned altitudes or create traffic conflicts during IFR flight.
Analogy
It is like easing off the gas before a stop sign instead of waiting until your bumper reaches the line. You start early because the vehicle needs time to slow smoothly.
Intuition Check
“Lead” does not mean the metal, and it does not mean the front edge of something here. It means starting the level-off action early, before the target altitude is reached.
Example Sentence 1
Climbing through 4,900 feet toward an assigned altitude of 5,000, the pilot used a 100-foot lead and began lowering the nose to level off.
Example Sentence 2
During descent the crew applied a 100-foot lead so the airplane leveled smoothly at the published step-down altitude.