Plain English Meaning
A way of moving your eyes around the cockpit instruments in a rectangle shape so you keep checking all of them in turn, instead of staring at just one.
Full Definition
An instrument scanning pattern in which the pilot's eyes move in a rectangular path around the instrument panel — across the top row of flight instruments and back along the bottom row — sampling each instrument in sequence rather than fixating on any single one. It is one of several recognized cross-check methods used in attitude instrument flying.
Context Anchor
Seen in instrument flying when learning how to scan the standard analog flight instruments.
Derivation
From Latin rectangulus, meaning 'right-angled.' The name simply describes the shape the eyes trace across the panel — a rectangle around the cluster of flight instruments.
Why Pilots Care
Prevents fixation on a single instrument and maintains balanced awareness of attitude, altitude, and heading.
Intuition Check
Rectangular does not mean the airplane is flying a rectangular route. It describes the pattern the pilot’s eyes follow across the instruments.
Example Sentence 1
During his first hood session, the student used a rectangular cross-check to keep his scan moving across all six flight instruments.
Example Sentence 2
While practicing turns under the hood, the rectangular cross-check kept altitude steady while the heading changed.