Definition
The process of calculating when and how to begin a descent from cruise altitude so the aircraft arrives at a required altitude over a specific point at the right speed, using known groundspeed, desired rate of descent, and the altitude to lose.
Plain English
Working out where to start coming down so you arrive at the next altitude restriction or the airport at the right height and speed, instead of being too high or too low.
Context Anchor
Seen during instrument flight planning, approach briefing, and any time a pilot must descend to meet a charted or assigned altitude.
Derivation
“Descent” comes from a Latin word meaning “to climb down.” “Planning” means arranging steps before acting. Together, the phrase points to bringing the airplane down by an organized plan, not by reacting at the last moment.
Why Pilots Care
Poor descent planning can cause altitude busts, rushed approaches, or unnecessary level-offs that burn extra fuel.
Grounding Statement
If the airplane is still too high when it is close to the airport or the next required altitude, the pilot may have to descend too steeply or abandon the plan and try again.
Intuition Check
Descent planning does not mean simply pushing the nose down when it is time to descend. It means working out the descent before it starts so the aircraft reaches the right place at the right altitude and speed.
Example Sentence 1
During cruise, the pilot did some quick descent planning and determined she needed to start down about 30 miles before the crossing fix to make the assigned altitude.
Example Sentence 2
With accurate descent planning the aircraft maintained a steady 500 feet per minute without any level segments.