Even very familiar companies like Zenith Aircraft company, part of a family light aviation empire including Zenair in Canada•, has to prepare well when FAA comes to visit. Specifically, this would be the agency’s KET or Kit Evaluation Team. When various representatives of the regulatory agency visit they use a multi-page list to assure that a kit aircraft meets the requirement that 51% of the kit is built by the owner.
Formerly called Experimental Amateur Built (or EAB), many aviators simply say the “51% rule.” In earlier times, kit aircraft were scratch built — meaning a builder secured raw materials that had to be formed and finished while referring to drawings, a potentially very lengthy process. To ease the effort and increase sales, an industry developed to sell component kits. These have become increasingly sophisticated with qualities such as match-hole construction using CNC machines.
Making it easier for a builder to assemble his or her aircraft is good, but the kit manufacturer must be able to clearly demonstrate how the owner will do 51% of the work, as required. As you might imagine, this demands a thorough review of the kit.
To prepare for FAA’s visit, company staff spread out all the kit parts for their Cruzer model in a hangar bay at the factory, showing what the kit looks like as supplied to builders (this video addresses how Cruzer fits in Zenith’s line).
You can watch a short video below that Zenith recorded; it demonstrates the part count pretty well and from the time it took just to lay them all out neatly, you may get some concept for the build effort to follow.
Zenith kits “are supplied ready for assembly, using pulled (blind) rivets,” said Zenith. “Parts are pre-formed and finished at the factory, and supplied pre-drilled, mainly final hole-size and ready for riveting. Welded assemblies are welded at the factory, and wing spars are supplied factory-finished.”
“This is just the latest Zenith kit to be evaluated by the FAA so the outcome of this evaluation is really not in question,” observed Roger Dubbert, company demo pilot and customer service specialist.
As an EAB owners can choose engines, avionics, and other options as they like, demonstrating the flexibility the 51% rule offers. Zenith said that popular engines include Continental, Lycoming, UL Power, Rotax, and a number of auto conversions, such as Viking. “Instrument panels can also be fully customized by the builder/owner, ranging from full IFR glass panels (Dynon, Garmin and others) to basic ‘steam gauges’ and/or iPad panels,” added Zenith. Company president Sebastien Heintz added that his, “airplane[s] … can still be operated by a Sport Pilot.”
Photos show the company’s newest model the Zenith CH 750 Cruzer, “an economical all-metal two-seat cross-country cruiser based on the hugely successful STOL high-wing designs from aeronautical engineer Chris Heintz,” concluded Zenith.
The following time-lapse video shows the team carefully laying out all the airframe parts for their Cruzer model.
• For those who prefer to expedite the process of building Zenair offers a builder assist center. Get more info here on Zenair’s Two-Week Wonder program.