The Type Clubs tent is behind the EAA Vintage Aircraft Association headquarters at AirVenture. Photo by David Sakrison

DERs — designated engineering representatives—play a crucial role in keeping vintage aircraft flying. When a vintage airplane needs a major repair, a field modification, or a newly fabricated part to replace an original part, the DER is the one who approves the engineering data, certifying that the data are consistent with or superior to the original. The DERs are engineers-for-hire, whose knowledge of a particular aircraft system or structure has been certified by the FAA. Although they are not FAA employees, DERs help to streamline the work of the FAA in approving engineering data and field modifications.

Vintage aircraft present special challenges for their owners, DERs, and the FAA. "The expertise on these older aircraft is not in the FAA," said H.G. Frautschy, executive director of EAA’s Vintage Aircraft Association. "And that expertise will never again be in the FAA. The guys at the FAA who had that expertise came out of the aircraft industry in the 1930s, ’40s, and ’50s when it was new," he said. "They and their expertise have aged out of the agency."

The FAA’s current cadre of DERs is focused mainly on new approvals and engineering work. And they are typically limited to data approvals on a particular system or structure.

"You’ll have an engine DER, a propeller DER, a landing gear DER, an airframe DER, and so on," said Frautschy. "And if you want to hang a 90-horse engine on a plane that left the factory with 65 horses, you might need to hire three DERs to get the engineering approvals—an airframe DER, an engine DER, and a propeller DER. If you want to modify the landing gear on an old Aeronca, you might have to hire the same DER who is an expert in Boeing 747 landing gear struts. For the owner or restorer," he said, "the cost of hiring those DERs can be prohibitive."

On Wednesday at EAA AirVenture Oshkosh, Frautschy met with Kim Smith, John Colomy, and David Showers of the FAA’s Small Airplane Directorate to discuss the possibility of certifying a "new breed" of DERs—"vintage DERs" whose demonstrated expertise covers an entire vintage airplane. A VDER’s authority would be limited to one make of aircraft, though a single VDER could be certified for multiple aircraft. As proposed by VAA, VDERs would have "holistic" authority to approve engineering data on any system or structure on the specific aircraft.

"They would still have to demonstrate their expertise to receive VDER privileges," said Frautschy, "but the basic structures and systems designs of these vintage aircraft are covered within the education of any aeronautical engineer."

"Most of these [vintage] airplanes were hand-built," Frautschy explained. "They contain few if any castings or forgings. They use simple wood or metal structures and relatively simple engines."

The people who have the expertise on these airplanes are in the type clubs, Frautschy said, and their expertise is broader and more comprehensive than a single system or structure. "It makes sense," he added, "for the FAA to tap that expertise to assist owners and the FAA." A large type club like the American Bonanza Society might have several VDERs with expertise in various Bonanzas or Bonanza systems, Frautschy said. The Piper Cub Club might have a "Cub VDER" with spinner-to-tail expertise on the J-3 Cub. Other type clubs might share one or more VDERs with broad expertise on a variety of similar airplanes. "The idea," he explained, "is simply to make the best use of the vintage expertise that’s already out there."

Small Airplane Directorate Manager Kim Smith and her colleagues told Frautschy the idea made sense to them, too. It would reduce administrative review time at the FAA and would also provide for continuity, since the same VDERs would be involved in most of the approvals on a particular type of vintage airplane.

To learn more about EAA’s Vintage Aircraft Association and about aircraft type clubs, visit the VAA HQ and the Type Clubs Tent, south of Aeroshell Square at AirVenture, or visit online at www.EAA.org/vintage.