In the A320, spoilers play a crucial role in various phases of flight, including takeoff, landing, and in-flight speed control. The aircraft is equipped with five spoiler surfaces on the wings, each serving specific functions. Spoiler number 1 functions as a ground spoiler, extending only when the aircraft is on the ground. Spoilers 2, 3, 4, and 5 are utilized for speed brakes in the air and roll control.
The speed brake lever in the cockpit is designed to extend the speed brakes, but its interaction with ground spoilers depends on factors such as flap position. On the ground, with flaps not fully deployed, moving the speed brake lever aft extends the speed brakes (surfaces 2, 3, and 4) along with spoiler number 1. When flaps are fully deployed, the speed brakes are inhibited, and manually moving the lever extends only spoiler number 1. This behavior is intentional and allows for maintenance checks.
Notably, the speed brake lever cannot manually extend ground spoilers on Airbus aircraft. Spoilers are armed for takeoff and landing by lifting the speed brake lever when in the retracted position until a white mark appears. This arming is essential for spoiler deployment during rejected takeoffs and landing to reduce lift from the wings.
(Read United Boeing 737-9 MAX rejected takeoff)
The Airbus spoiler logic underwent changes due to incidents where pilots inadvertently left the speed brake lever extended during landing, resulting in spoiler non-deployment. With the updated logic, if the speed brake lever is left extended, it automatically arms, ensuring spoiler deployment upon landing.
The current spoiler logic, as per the A320 FCOM, outlines conditions for spoiler extension during rejected takeoff and landing phases. Ground spoilers automatically extend based on factors such as wheel speed, thrust lever positions, and the status of the speed brake lever. These conditions are in place to enhance safety and prevent incidents related to spoiler activation.
Author – Nischal Paudel (Pilot)
