From our "So THAT’S what it’s for!" file, we thought we'd share this insightful tidbit from this week's "Dateline NBC" expose on the Boeing 737 rudder problem:

RUDDER STEERS THE PLANE
The rudder is the vertical panel attached to the tail that steers the plane left or right. It’s moved by pedals in the cockpit. The pilot pushes the right rudder pedal, the plane turns right. He pushes the left rudder pedal, it turns left.