TY91/TY92 Minor Change Library

At Trig we have developed a set of EASA approved upgrade instructions that document the process of installing TY91 or  TY92 radios in a range of aircraft. Trig installers can use these instructions to achieve airworthiness compliance without needing to seek further approval from EASA.

These Minor Change Approvals are free.

First – reference the Applicable Aircraft Model List (bottom of page) to access the relevant Minor Change Approval Certificate for your aircraft.

Next – check the certificate the find the relevant ‘Associated Technical Document’ this will direct you to the applicable Minor Change Master Instructions reference.

Finally – Use this reference to view the related Minor Change Master Instructions document. This must be followed as part of the installation and can be found in the section below.

Minor Change Master Instructions

The Minor Change master instructions are available for download here.

SUP/TY91 004, issue 1.0 – Fixed Wing (CS-23) TY91/TY92

SUP/TY91/003, issue 1.0 – Fixed Wing (CS-23) TY91/TY92

SUP/TY92/001, issue 1.0 – Fixed Wing (CS-23) TY91/TY92 Instructions (Pre 2014 Approval)

Minor Change Approval Sheets

Each approved aircraft type has a corresponding approval certificate available for download here.  Note that some of these approval certificates include standard text inserted by EASA which says “The installation of this modification by third persons is subject to written permission of the approval holder”.  For the avoidance of doubt, we hereby grant that permission, and this web page may be referred to as evidence of that permission.

If you are installing a TY91 or TY92 VHF Radio in an aircraft type NOT shown here, but for which the minor change instructions would apply, Trig Avionics grant you permission to use the published minor change instructions as the basis for your own application.

The list below does not include every model number. Please refer to the certificate or Master Instructions for all applicable aircraft models.

Applicable Aircraft using SUP/TY92/001 Instructions

American Champion

7 series, S7 series


C150 A/B/C/D/E/F/G/H/J/K/L/M, A150 K/L/M, C152, A152, C172



Robin (Alpha Aviation Concept)

HR200 series / DR400 series