Design-21 Projects

A summer evening of BBQ, laughter, and team spirit. Design-21 Projects came together to unwind, reconnect, and celebrate the commitment everyone brings to work every day. 🍖🔥

Happy World Tourism Day! 🌍✈️ Every destination starts with a journey. Today, we celebrate the role of aviation in connecting people, cultures, and opportunities across the globe. Here's to safe skies, memorable travels, and the professionals who make every journey possible.
🌐 https://d21projects.com/

Cabin & Cargo Compartment Engineering Services (Part 2) ✈️

Continuing our look at how D21 Projects supports cabin and cargo compartment modifications, this time covering compartment linings, crew rest areas, and emergency equipment layout updates (EEL updates, non-halon extinguishers, AED/ELT integration).

We also handle placards and markings, ownership and lease data plates, registration changes, and aircraft livery updates, all backed by the necessary engineering documentation to meet applicable regulatory requirements.
EASA Minor Change or Repair approval can be provided for changes or repairs classified as Minor, in accordance with D21 Projects' DOA Terms of Approval.

🌐 https://d21projects.com/
📧 [email protected]

We are seeking a Part 21 Design Engineer! ✈️ Join our growing team as an ambitious and highly motivated engineer, working on cabin design and exterior livery modification projects for airline operators and aircraft lessors worldwide.

The successful candidate will prepare and review design and certification documentation, verify compliance with EASA airworthiness requirements, and liaise with maintenance organisations, customers, and EASA/NAA authorities throughout the project lifecycle.

📩 Apply via email: [email protected]
🔗 Learn more and apply online: https://3plexgroup.com/careers/part-21-design-engineer/

Cabin & Cargo Compartment Engineering Services ✈️

From a single seat cover replacement to a full cabin reconfiguration, D21 Projects supports operators and lessors with a wide range of interior modification needs — including cabin textiles, LOPA changes, placards and branding updates, galley and lavatory work, and flight deck interiors.

Whether it’s a full cabin overhaul or a smaller cosmetic update, our engineering team ensures that every change meets applicable regulatory requirements while providing the necessary engineering documentation.

EASA Minor Change or Repair approval can be provided for changes or repairs classified as Minor, in accordance with D21 Projects’ DOA Terms of Approval.

🌐 https://d21projects.com/
📩 [email protected]

What began in 2013 continues to expand. With our AT.CAMO.544 Approval secured in June 2026, 3PLEX AERO AT GmbH brings our presence into Austria, another step forward for 3PLEX GROUP. Growing stronger, sharper, and ready for the road ahead.

Engineering Services & Approvals: Where Our Capabilities Apply ✈️ Our engineering services cover Cabin and Cargo Compartments, Avionics, Electrical and Environmental Control Systems, and Flight Engineering.

Our Minor Change and Minor Repair Approvals extend across external schemes, placards and markings, cabin interiors, cargo compartments, electrical cabin systems, and flight deck interiors.

Looking for support on your next aircraft project?
📩 Contact us: [email protected]
🌐 Visit our website: www.d21projects.com