The airplane spoilers function is to disrupt, or spoil, the flow of air across the upper surface of the wing. They are usually found on larger aircraft, which can have two types installed. The in-flight airplane spoilers are small and designed to reduce the lifting capability of the wing just enough to allow the aircraft to descend quicker without gaining airspeed. Although the flaps can also perform this function, the spoiler is intended to be used temporarily, while the flaps are typically used for longer durations such as during the approach and landing. The ground spoilers (Img. 1) typically deploy automatically on landing and are much larger than their in-flight cousins. They are used to completely destroy the lifting ability of the wing upon landing, ensuring that the entire weight of the airplane rests firmly on the wheels, making the brakes more effective and shortening the length of runway needed to stop the aircraft.
During the development phase, a certification plan is established in cooperation with representatives from the airworthiness authorities, including a list of all certification tests. Compliance with the rules has to be demonstrated to obtain the type certification. Due to the fact that several tests have to be performed during the flight test phase, certain major tests on ground are necessary to get clearance for the first flight. These tests include for example (list not exhaustive):
• 1 g bending test of wings (checking for example gaps and interference of flaps and slats)
• maximum wing bending at limit load condition
• functioning of flight controls (aileron, spoiler) under limit load
References :
Commercial Aircraft Composite Technology