cruise

cruise

i. Flight from the top of the climb to the top of the descent, carried out at speed and engine settings that result in fuel economy and a long engine life.
ii. A flight condition that permits an aircraft to operate smoothly and efficiently for a long period.
iii. When used in ATC (air traffic control) clearance, it means to authorize a pilot to conduct flight at any altitude from the minimum IFR (instrument flight rules) altitude up to and including the altitude specified in the clearance. The pilot may level off at any intermediate altitude within this block of airspace. Climb or descent within the block is to be made at the discretion of the pilot. However, once the pilot starts the descent and verbally reports leaving an altitude in the block, he or she may not return to that altitude without additional ATC clearance.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved