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

SA4659SW

Installation of S-TEC system 60 two axis flight guidance system, model ST-074 with optional autotrim system and with optional flight director steering horizon. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised May 11, 1982. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
Beechcraft Corporation
Models
76
Type certificate
A29CE
On this site
Beechcraft 76 Duchess 151 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 21, 2026.