enroute turning area
enroute turning area[en′rüt ′tərn·iŋ ‚er·ē·ə]
An area of specified dimensions used by an aircraft when a change of course is necessary; the area extends beyond the primary and secondary obstruction clearance areas and is provided with adequate protection; turning area criteria supplement the basic airways and route segment criteria to protect the aircraft. Also known as turning area.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.