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

ST223CH

Installation of a Stage 3 hushkit when powered by P&W JT8D-7, JT8D-9, JT8D-15, or JT8D-17 Series Engines. Held by Avaero. Last revised December 1, 2009. System: engine.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company; The Boeing Company; The Boeing Company
Models
737-100 Series, 737-200 Series, 737-200C Series
Type certificates
A16WE, A16WE, A16WE
On this site
Boeing 737 2,892 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.