Aircraft Structure Repair
Services & Approvals
In support of our wide-ranging design capability we perform stress analysis, fatigue and damage tolerance analysis in order to demonstrate compliance with necessary requirements and to ensure safety and continued airworthiness of the aircraft. Previous work includes:
- Cargo Freighter Conversions
- Introduction of Freight Restraint Systems
- Flooring rework
- Large External Radome/ Antenna Provisions
- Introduction of Additional Emergency Exits
STC Twenty One have approved the following and many more. For all STC Approvals held by STC Twenty One refer to this document & MOD STORE. Contact STC Twenty One for 1200+ minor design changes.
STC Twenty One has the approval privilege to design changes to primary, secondary and tertiary structure, on large and small aircraft and rotorcraft. STC Twenty One also hold the privilege to design and approve structural repairs to all aircraft types.

Aircraft Structure Repair
Speak To The Team
Our engineers and CVEs have in excess of 70 years of experience in aerospace structures.
UK CAA Approved Design Organisation
STC Twenty One
All aircraft modifications and aircraft repairs are managed by our UK CAA approved Design Office represented by STC Twenty One (UK.21J.0198).
What We Offer
Services
STC Twenty One Limited holds a Part 21 Subpart J DOA enabling it to certify UK CAA 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 UK.21J.0198 through CAA.
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.