"The 737 design enhancements allow operators to fly increased payload in and out of airports with runways less than 5,000 feet long. The design enhancements include a two-position tail skid that enables reduced approach speeds, sealed leading-edge slats that provide increased lift during takeoff, and increased flight spoiler deflection on the ground that improves takeoff and landing performance"
What are the sealed leading-edge slats in B737 short field performance, and how are they different from the normal leading slats in typical B737?