Thank you NHS & Key Workers

STC Twenty One Ltd is proud to announce our collaboration with DHL for the approval of External 'Thank You' Decals that were added to their aircraft this weekend. We would…
STC Twenty One
May 5, 2020

Brexit Statement

As of 23:00 GMT on January 31st 2020, Britain has now left the EU. Amid much speculation of the impact this could have across our industry, STC Twenty One Ltd…
STC Twenty One
February 5, 2020

What is ADS-B Out?

About our AML STC ADS-B Out – Automatic Dependant Surveillance-Broadcast Mandate due date: 7th June 2020 (Europe, EASA) 1st January 2020 (USA, FAA) What is ADS-B? ADS-B is a broadcasting…
STC Twenty One
September 5, 2019

EASA Approved Design Organisation

STC Twenty One

All Aircraft modifications and Aircraft repairs are managed by our EASA approved Design Office represented by STC Twenty One (EASA DOA.21J.198).

What We Offer


STC Twenty One Limited holds a Part 21 Subpart J DOA enabling it to certify EASA approved STCs and Major Repairs. Additionally, where a design change or repair is classified as minor, STC Twenty One Limited is authorised to approve them under the DOA using approval reference EASA.21J.198.

Our employees are spread across our Avionics, Mechanical, Quality and Commercial Teams with a high level of experience and certification enabling the company to perform specialised services on engines and aircraft. Read more about our Services.

Get in Touch

Contact Us

Need more information or want to arrange to meet us?

+44 (0) 1332 576830

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