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

SA4-592

Eonite covering on ailerons and rudder. Held by Lott William C, which holds 24 approved modifications in all. Last revised January 1, 1970. System: flight controls.

What it applies to

Kind of product
Aircraft
Design holder
General Dynamics Corporation; General Dynamics Corporation
Models
BT-15, BT-13 Series
Type certificates
A-2-571, A-2-571
On this site
Consolidated Vultee BT-15 8 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.