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

SA4110WE

Installation of spring-type tail wheel strut assembly. Held by Serv-Aero Engineering INC, which holds 32 approved modifications in all. Last revised October 20, 1993. System: landing gear.

What it applies to

Kind of product
Aircraft
Design holder
Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.; Thrush Aircraft Inc.
Models
600 S-2D, S-2R, S2R-G10, S2R-G5, S2R-G6, S2R-R1340, S2R-R1820, S2R-R3S, S2R-T11, S2R-T15, S2R-T34, S2R-T45, S2R-T65
Type certificates
A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW, A4SW
On this site
Ayres Corporation S-2 244 registered
Thrush Aircraft Inc S-2 102 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 5, 2026.