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

ST01749CH

Installation of a 4-tube Universal Avionics Electronics Flight Instrumentation System (EFI-550). Held by Elliott Aviation Technical Products, which holds 57 approved modifications in all. Last revised December 20, 2002. System: instruments and avionics.

What it applies to

Kind of product
Aircraft
Design holder
Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.
Models
35, 35A (C-21A), 36, 36A
Type certificates
A10CE, A10CE, A10CE, A10CE
On this site
Learjet 35 161 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.