Definition
A flight condition in which the airplane maintains a fixed altitude above a reference (typically mean sea level) and a fixed airspeed at the same time. Holding both simultaneously means the airplane's total mechanical energy — the sum of its potential energy (from altitude) and kinetic energy (from airspeed) — is not changing.
Plain English
The airplane is staying at the same height and going the same speed. Nothing is climbing, descending, speeding up, or slowing down.
Context Anchor
Used when discussing how a pilot manages the airplane’s energy state during normal flight, especially when comparing steady flight with climbs, descents, acceleration, or slowing down.
Why Pilots Care
It shows that power input exactly balances drag, so any change in altitude or speed signals an energy imbalance that must be corrected by throttle or pitch adjustment.
Grounding Statement
Picture cruising straight and level on a calm day with the altimeter parked on 5,500 feet and the airspeed indicator steady at 110 knots — that is constant altitude and airspeed.
Intuition Check
Constant does not mean the pilot never moves the controls. It means the airplane’s height and speed remain steady, even if small corrections are needed.
Example Sentence 1
During the cruise leg, the pilot trimmed the airplane to maintain constant altitude and airspeed while reviewing the next checkpoint.
Example Sentence 2
After leveling off, the student practiced holding constant altitude and airspeed to establish a stable energy state before beginning descent.