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

ST10279SC

Installation of Avtech Display Switching Unit with a Honeywell EGPWS in accordance with Aircraft Systems and Manufacturing Top Drawing List 5644-0001-00, Revision B, dated September 1, 2004, or later FAA approved revision. FAA approved Airplane Flight Manual Supplement Document No. 5644-2160-00, Revision I.R., dated September 2, 2004, is required. Held by Aircraft Systems & Mfg, which holds 60 approved modifications in all. Last revised September 3, 2004. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company; The Boeing Company
Models
727-100 Series, 727-200 Series
Type certificates
A3WE, A3WE
On this site
Boeing 727 37 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.