stability augmentation system


stability augmentation system

[stə′bil·əd·ē ȯg·mən′tā·shən ‚sis·təm] (aerospace engineering) Automatic control devices which supplement a pilot's manipulation of the aircraft controls and are used to modify inherent aircraft handling qualities. Abbreviated SAS. Also known as stability augmentors.

stability augmentation system (SAS)

i. An autostabilizer system that is essentially a damping device incorporated in most helicopters. The stability augmentation system enhances stability but does not have the ability to hold a given datum.
ii. Various forms of auxiliary subsystems added to the primary flight control to achieve desired aircraft characteristics by selection of variable gain in feedback loops from aircraft control surfaces. These devices often have limited authority and do not move the pilot's controls.
In many aircraft, an inoperative SAS makes the aircraft unairworthy.