STC Twenty One Limited is an EASA approved Design Organisation located in the East Midlands. STC Twenty One Limited provides EASA approved major (Supplemental Type Certificate) and minor changes/repairs for a wide variation of aeroplane and rotorcraft types.
The scope of approval held by STC Twenty One Limited permits design changes for the following:
Radio & Navigation Systems
Hydro Mechanical and Environmental Control Systems
Flight Conditions and Permit to Fly Approval
Our contact details are
Address: The Waldorf Centre, 1290 London Road, Alvaston, Derby DE24 8QP .
Tel: +44 (0) 1332 576 830 Fax: +44 (0) 1332 576 831