Let us help you demystify the different certification DART can offer.

TC: A Type Certificate (TC) is a design approval by the Civil Aviation Authority (CAA), aka FAA, when an applicant demonstrates that a product—airframe, engine, propeller—complies with applicable regulations. The TC normally includes type design, operating limitations, a Type Certificate Data Sheet (TCDS), relative regulations and other CAA conditions or limitations, and is basis for other approvals, including production and airworthiness approvals*

STC: A Supplemental Type Certificate (STC) is issued by the FAA approving a product modification. The STC defines product design change, how the modification affects an existing type design, and lists serial number effectivity. It also identifies the certification basis listing specific regulatory compliance for the design change.*

*http://www.aerofiles.com/STC-Group2.html

PMA & PDA :

In the FAA system, PMA has two meanings:
a. A Parts Manufacturing Approval
b. An approval for a Replacement Part

Interesting Facts

• A PDA (Parts Design Approval) is a TCCA (Transport Canada) approval for a replacement part. Under the TCCA system, there is no difference in the certification work required to obtain a PDA vs an STC. However, at the end of the process, the final documentation one receives is different for a PDA than for an STC.
• A PDA can only be issued for a non-critical replacement part. Therefore, while we can obtain a PDA for a wearplate (landing gear sub-component), TCCA will not issue a PDA for a crosstube or a skidtube (primary/structural components).
• Once DART obtains a TCCA PDA, it is automatically accepted by the FAA and EASA without validation through the respective bilateral agreements. However, some operators are still uncomfortable with the PDA concept since the vehicle to certify a replacement part within their region is an STC, not a PDA or a PMA. To accomodate this matter, DART has started to obtain STC’s for some of its PDA parts.