Plain English Meaning

Climbing or descending at a steady number of feet per minute, instead of speeding up or slowing down vertically along the way.

Full Definition

A descent or climb performed at a fixed, unchanging vertical speed, typically expressed in feet per minute (fpm) on the vertical speed indicator. The pilot adjusts pitch and power so the aircraft gains or loses altitude at the same rate throughout the maneuver.

Context Anchor

Seen when entering and holding straight climbs or descents by reference to flight instruments.

Derivation

comes from a Latin idea meaning “standing firm” or “unchanging.” Rate means an amount measured time. Together, constant rate means the amount of altitude change per minute stays steady.