Most DARs have limited and/or certain "functions" authorized by the FAA based on their experience and technical background.
Qualifications and policies for appointment of Designated Airworthiness Representatives are established in FAA Order 8100.8.
However, starting in 2015, some of these expansion requests have been denied due to national policy changes.
The aircraft owner or the owner's agent may either contact a DAR directly or contact the local FAA Flight Standards District Office (FSDO) or Manufacturing Inspection District Office (MIDO) for assistance.
Consult the Designee Management System to identify a local DAR.