ANTI-SKID SYSTEM

Large aircraft with power brakes require anti-skid systems. It is not possible to immediately ascertain in the flight deck when a wheel stops rotating and begins to skid, especially in aircrafts with multiple-wheel main landing gear assemblies. A skid not corrected can quickly lead to a tire blowout, possible damage to the aircraft, and control of the aircraft may be lost. One of the important issues to realize is that the anti-skid system greatly increases the effectiveness of braking. In very simplified terms, the anti-skid system provides the greatest possible brake pressure while not allowing the wheels to lock due to an excessive brake pressure being applied. Without the anti-skid system (manual braking) the braking effectiveness is reduced.

• "The anti-skid computer compares wheel speed to aeroplane reference speed to provide a slip ratio for maximum braking performance." Correct. These systems use a computer that, during ground movement when braking, which constantly compares the measured values of individual wheels (actual rotational speed) with the desired optimum parameters, providing a slip ratio for maximum braking performance.
• "If a pilot is careful when braking manually, he/she will be able to achieve the same braking efficiency as if braking with anti-skid." Incorrect. A pilot will never reach the same performance as a properly functioning anti-skid system. The anti-skid system senses when a brake starts to skid and will reduce braking pressure to avoid the wheels from skidding, a pilot won’t come close to the same performance.