History of Leading Edge Devices
History of leading edge devices
Slats were first developed by Handley-Page in 1919; licensing the design became one of their major sources of income in the 1920s. The original designs were in the form of a fixed slot in the front of the wing, a design that was found on a number of STOL aircraft. This design was used for aircraft doing racing, the fixed slat helped some aircrafts to improve the performances and win a few races as well as setting up new records.
During World War II German aircraft commonly fitted a more advanced version that pushed back flush against the wing by air pressure to reduce drag, popping out on springs when the airflow decreased during slower flight. However, the most famous slats of that time belonged to the German Fieseler Fi 156 Storch. These were similar in design to retractaible slats, but were fixed non-retractable slots. The slotted wing allowed this aircraft to take off into a light wind in less than 45 m (150 ft), and land in 18 m (60 ft) due to the increase in lift.
In the post-war era slats have generally been hydraulically or electrically operated, allowing for more complex and efficient designs these can be find on most common commercial and freighter aircraft.