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

SA1-488

Various radio and modifications plus rearrangement of control head on pedestal and revised radio electrical circuitry. Held by Butler Aviation, which holds 7 approved modifications in all. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
Tracor Flight Systems Inc.
Models
340
Type certificate
6A6
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 22, 2026.