SA1300WE
Installation of Brittain Model ACS-1 Stability Augmentation system. Held by Brittain Industries, INC, which holds 232 approved modifications in all. Last revised November 19, 2013. System: other and general.
What it applies to
What an approved modification is
A supplemental type certificate is the FAA's approval of a change to a certified design: a new engine or propeller, avionics, an autopilot, floats, a parachute, a larger fuel tank, an ice-protection kit. The company holding it may sell the kit and the paperwork to owners of the listed models; the modification then becomes part of that aircraft's record. The FAA's list says what was approved and for which models, not how many aircraft carry it.
Source: FAA supplemental type certificates (Dynamic Regulatory System). Register counts from the FAA register of October 20, 2026.