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

SA09398AC-D

Installation of S-TEC System 20/30 Single and Two Axis Automatic Flight Guidance Systems, Model ST-851-20/30. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised December 17, 1998. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
SOCATA; SOCATA; SOCATA; SOCATA; SOCATA
Models
TB 10, TB 20, TB 200, TB 21, TB9
Type certificates
A51EU, A51EU, A51EU, A51EU, A51EU
On this site
Daher (Socata) TB 10 53 registered
Daher (Socata) TB-20 200 registered
Daher (Socata) TB 9 34 registered
Daher (Socata) TB200 11 registered
Daher (Socata) TB21 57 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.