Under Title 49 of the United States Code (49 USC) 44702(d), the FAA may delegate to a qualified private person a matter related to issuing certificates, or related to the examination, testing, and inspection necessary to issue a certificate on behalf of the FAA Administrator as authorized by statute to issue under 49 USC 44702(a).
The Organization Designation Authorization (ODA) program is the means by which the FAA grants designee authority to organizations or companies. The regulations addressing the ODA program are found in Title 14 of the Code of Federal Regulations (14 CFR) part 183, subpart D, sections 183.41 through 183.67.
ODA holders are typically authorized to conduct the types of FAA functions which they would normally seek from the FAA. For example, aircraft manufacturers may be authorized to approve design changes in their products and repair stations may be authorized to approve repair and alteration data.
Regular FAA oversight of an ODA is accomplished by a team of FAA engineers and inspectors to ensure the ODA holder functions properly and that any approvals or certificates issued meet FAA safety standards.
A listing of ODA holders and their authorized functions, along with contact information, can be found in the ODA Directory (PDF).