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

SA2726SO

Installation of CAS-81 TCAS II system. Held by Honeywell International INC., which holds 142 approved modifications in all. Last revised January 19, 2022. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation
Models
DC-9-82 (MD-82), MD-88, DC-9-81 (MD-81), DC-9-83 (MD-83), DC-9-87 (MD-87)
Type certificates
A6WE, A6WE, A6WE, A6WE, A6WE
On this site
Mcdonnell Douglas Aircraft Co MD-88 10 registered
Mcdonnell Douglas DC-9 93 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 5, 2026.