STC Twenty One Limited
STC Twenty One Limited is a Design Organisation (DOA) located in the East Midlands, providing aerospace engineering services approved and regulated under the UK Civil Aviation Authority (CAA). The company offers major and minor changes/repairs for various aeroplane and rotorcraft types.
- Avionics modifications
- Structural modifications
- Electrical modifications
- Minor changes and repairs
- Cabin related modifications
- Major STC (Supplemental Type Certificate)
- Approval of Flight Conditions & Permit to Fly
- Environmental Control Systems (ECS) modifications