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

SA2573SO

Installation of an Emergency Floor Path Lighting System. Held by Astronics Luminescent Systems INC, which holds 11 approved modifications in all. Last revised June 2, 2022. System: electrical power.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company
Models
DC-9-51
Type certificate
A6WE
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 7, 2026.