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

SA3642NM

Installation of Hartzell HC-E3YR-2ATF/FC8468( )-8Q (left engine) and HC-E3YR-2ALTF/FJC8468( )-8Q (right engine) propeller assemblies. PA-31-350 (T-1020) and PA-31-350 (Chieftain). Serial numbers 31-7405218, 238, 485, 490; 31-7552043, 076; and 31-7652144 are ineligible for this installation. Held by Frontier Flying Service INC., which holds 2 approved modifications in all. Last revised February 4, 2020. System: propeller.

What it applies to

Kind of product
Aircraft
Design holder
The New Piper Aircraft Inc.
Models
PA-31-350
Type certificate
A20SO
On this site
Piper PA-31 Navajo and Chieftain 935 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.