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

SA3255SW-D

Installation of Mitchell automatic flight system model AK 679 consisting of Century III autopilot with optional radio coupler and glide slope coupler. Held by Century Flight Systems INC, which holds 765 approved modifications in all. Last revised March 28, 1984. System: flight controls.

What it applies to

Kind of product
Aircraft
Design holder
Piper Aircraft Inc.; Piper Aircraft Inc.
Models
PA-32RT-300, PA-32RT-300T
Type certificates
A3SO, A3SO
On this site
Piper PA-32 Cherokee Six, Lance and Saratoga 3,917 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 20, 2026.