Plain English Meaning

Speed limits that aren't painted on the airspeed indicator dial but that the pilot still has to respect. They're listed in the aircraft's handbook and apply when doing certain things, like extending the landing gear or flying through rough air.

Full Definition

Airspeed restrictions, beyond those marked on the airspeed indicator, that apply to specific aircraft configurations or operations. These include limits such as maximum landing gear operating speed, maximum landing gear extended speed, maximum flap extended speed, maneuvering speed, and best rate or angle of climb speeds. They are published in the Pilot's Operating Handbook (POH) or Airplane Flight Manual (AFM) rather than shown by color-coded arcs on the airspeed indicator.