Definition
An autopilot vertical mode that commands a climb or descent to a pilot-selected altitude while the autothrottle (or pilot manually) sets a fixed power setting, with the autopilot pitching the aircraft up or down as needed to hold a target airspeed or Mach number during the change.
Plain English
A button you press on the autopilot to climb or descend to a new altitude. Power stays at a chosen setting, and the autopilot raises or lowers the nose to keep the airplane at the speed you want until it levels off at the new altitude.
Context Anchor
Seen on an autopilot or flight guidance control panel during climbs and descents, especially when changing altitude under instrument procedures or ATC instructions.
Why Pilots Care
Allows precise, hands-off altitude transitions while protecting speed and performance limits.
Grounding Statement
In FL CHG, speed is the priority; the airplane raises or lowers the nose as needed while moving toward the selected altitude.
Intuition Check
FL CHG does not mean the airplane will automatically choose the best climb or descent rate. It means the system is changing altitude while trying to hold the selected speed.
Example Sentence 1
When ATC cleared them to climb to 24,000 feet, the captain selected the new altitude and pressed FL CHG to begin the climb.
Example Sentence 2
During descent, engaging FL CHG let the autopilot maintain 250 knots while leveling at the assigned flight level.