Answer: The slats on the leading edge of the wing allow the airplane to take off and land at lower speeds. When extended they alter the airflow so the wing can produce more lift at lower speed.

Boeing said the part known as a leading-edge slat track — a mechanism that modifies the lift and drag characteristics of the plane's wing during takeoffs and landings — is among 148 parts from ...

The assemblies in question are the slat tracks. They guide the slats on the aircraft’s wings that adjust the leading edge. Deployment of the slats allows an aircraft to fly safely at lower speed.

Japanese transport officials have announcing finding another Boeing 737-700 missing a washer in the wing leading-edge slat-track one week after a similar missing part led to the explosion of a ...