Stability Augmentation System (SAS) Computer

BAE Systems (Operations) Ltd
Part/SVID AP00031585-1460
Ser. 0114
NSN 7021-99-300-1460
Code K0656

On the Nimrod MRA4 the longitudinal stability was poor and subsequently corrected by a Stability Augmentation System. A Stability Augmentation System (SAS) is a type of automatic flight control system; however, instead of maintaining the aircraft required altitude or flight path, the SAS will move the aircraft control surfaces to damp unacceptable motions. SAS automatically stabilizes the aircraft in one or more axes. The most common type of SAS is the yaw damper which is used to reduce the Dutch roll tendency of swept-wing aircraft. Some yaw dampers are part of the autopilot system while others are a stand-alone system.