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

SA285CE

Installation of Lycoming IO-360-B1B engines and Hartzell HC-C2YR-2RA/7666A-2 propellers. Gross weight increase to 3684 lbs on PA-23 and 4000 lbs on PA-23-160. Data required: PA-23: Doyn dwg 1500, Rev. C, except for Hartzell HC-922K-2B/8447-12A props. Doyn dwg 1507, Rev. C, PA-23-160: Doyn dwg. 1800, Rev. C, except for Hartzell HC-922K-2B/8447-12A props. Dwg. 1807, Rev. C. Held by D'Shannon Products LTD., which holds 118 approved modifications in all. Last revised July 14, 2011. System: propeller.

What it applies to

Kind of product
Aircraft
Design holder
Piper Aircraft Inc.; Piper Aircraft Inc.
Models
PA-23, PA-23-160
Type certificates
1A10, 1A10
On this site
Piper PA-23 Apache and Aztec 1,316 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 21, 2026.