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

SA2499SW

Installation of Dual Collins INS-61B Inertial Navigation System with DME Update on No. 1 INS and Manual Update on No 2 INS. Held by Sierra Industries, INC, which holds 164 approved modifications in all. Last revised December 1, 1999. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company
Models
727-100 Series
Type certificate
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.