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

SA3486SW-D

Installation of Century Automatic Flight System Model AK993 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 August 23, 1999. System: flight controls.

What it applies to

Kind of product
Aircraft
Design holder
Cessna Aircraft Company; Cessna Aircraft Company
Models
172P, 172R
Type certificates
3A12, 3A12
On this site
Cessna 172 Skyhawk 20,669 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.