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

ST301CH

Installation of an AlliedSignal CAS-67A TCAS II system. Held by Electrosonics, which holds 76 approved modifications in all. Last revised February 20, 2004. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company
Models
500, 550, S550, 560
Type certificates
A22CE, A22CE, A22CE, A22CE
On this site
Cessna 500 Citation I 63 registered
Cessna 550 Citation II 500 registered
Cessna 560 Citation V, Ultra, Encore and Excel 1,341 registered
Cessna S550 94 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 7, 2026.