The U.S. aircraft register, updated daily
Approved modifications · supplemental type certificate · current · issued

SA8524SW-D

Installation of a Century Automatic Flight System, Model AK1047 consisting of a /Century 2110/2130/2131/2150/2151 autopilot. Held by Century Flight Systems INC, which holds 765 approved modifications in all. Last revised May 8, 1998. System: flight controls.

What it applies to

Kind of product
Aircraft
Design holder
The Cessna Aircraft Company; The Cessna Aircraft Company
Models
421, 421A
Type certificates
A7CE, A7CE
On this site
Cessna 421 Golden Eagle 770 registered
The FAA's record
On the FAA's site

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 5, 2026.