obstacle clearance box

obstacle clearance box

[′äb·stə·kəl ¦klir·əns ‚bäks]

(navigation)

A rectangle on an aeronautical chart which encloses a number indicating the obstacle clearance required (in feet) on an approach segment where the box appears.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.