The Designated Engineering Representative (DER) system enables the FAA to use qualified technical people to perform certain examinations, testing, and inspections necessary to determine compliance with applicable airworthiness standards. A DER offers technical expertise with state-of-the-art knowledge and understands the framework of critical regulations that allow technology to be applied safely. A DER may approve or recommend approval of engineering technical data within the limits of their authority by means of FAA Form 8110-3, Statement of Compliance with the Federal Aviation Regulations. The FAA may also authorize a DER to witness FAA compliance tests and perform compliance inspections. Specific roles, authorized areas, and responsibilities of a DER are established by an agreement between the FAA and the DER at the initial appointment of a DER, and when required, for FAA approved specific projects.
TLG has two full time DERs on staff, FAA Loads and Dynamics DER (14 CFR Part 23 and 25), Steve Muenzberg; and FAA Flutter DER (14 CFR Part 23 and 25), and Flight Analyst DER (14 CFR Part 23), Robert Lind. These specialized engineering areas are required for new aircraft certifications and major aircraft modifications. In addition, TLG has working arrangements with a number of DERs in the disciplines of Flutter, Stress, Fatigue and Damage Tolerance, Icing, Control Systems, Power plant, Noise, other DER coordination available as needed.