Final answer:
Ground spoilers are armed to assist in decelerating the aircraft after landing. They can be manually activated by the pilot or automatically armed when certain conditions are met such as deploying the landing gear or engaging the thrust reversers.
Step-by-step explanation:
Ground spoilers are armed to assist in decelerating the aircraft after landing. They are typically found on the wings of the aircraft and are controlled by the pilots or an automated system. When the aircraft lands, the ground spoilers extend upwards, disrupting the airflow over the wing and increasing drag, which helps in slowing down the aircraft.
The ground spoilers are armed in different ways depending on the aircraft. Some aircraft have manual arming, where the pilot physically activates the ground spoilers using a switch or lever. Others have automatic arming, where the ground spoilers are automatically armed when the landing gear is deployed or the thrust reversers are engaged.
For example, in a typical commercial jetliner, the ground spoilers are armed automatically when the thrust reversers are engaged. This ensures that the ground spoilers are ready to deploy and assist in decelerating the aircraft as soon as it touches the ground.