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

SA5923SW

Installation of modifications to align the vertical control surface with airplane centerline. Held by Hershey Flying Service INC, which holds 12 approved modifications in all. Last revised November 16, 2017. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
Ag Cat Corporation; Ag Cat Corporation
Models
G-164B, G-164A
Type certificates
1A16, 1A16
On this site
Ag-Cat Corporation G-164 5 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.