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

SA1489CE

Removal of 24-inch wide executive door and installation of 36-inch wide cargo door per AVCON Drawing List 36000 stamped FAA Approved with a date of May 8, 1979, July 3, 1980, November 15, 2010, or later approved revision for Learjet Models 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A, 36, and 36A. Held by Avcon Industries INC, which holds 121 approved modifications in all. Last revised November 15, 2010. System: airframe structure.

What it applies to

Kind of product
Aircraft
Design holder
Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.; Learjet Inc.
Models
25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), 36, 36A
Type certificates
A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE, A10CE
On this site
Learjet 25 23 registered
Learjet 31 119 registered
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 20, 2026.