August 2, 2014 - Chris Heinz, loved flying his Zipper ultralight design in the evenings after the heat and winds of the day had subsided. But there was a challenge.
“You have a lot of bugs and flies in your face,” Heinz said. “I really liked that plane because you could fly really slowly and admire the landscape or whatever you wanted to look at. But I didn’t like all those flies.”
Heinz is an aeronautical engineer and designer of all Zenith Aircraft Company’s models.
Those evening flights provided the impetus to design an airplane that has about the same takeoff, landing, and speed characteristics of the Zipper, but in an enclosed airplane. The resulting design was the CH 701, now one of the more popular options for builders interested in short takeoff and landing (STOL) capabilities.
But as it is with any aircraft design, the STOL capability comes only with compromises in other areas of aircraft performance. One of those compromises in the CH 701, and its wider cabin variant the CH 750, was cruise speed.
After noticing modifications that a number of builders were making to the designs in the interest of increased cruise performance, Heinz looked to offer a version of the plane with better cross-country speeds.
The result of Heinz’s effort is the CH 750 Cruzer, and EAA’s One Week Wonder project of building an airplane this week is a kit-built example of the design.
“We tried to make it a little bit faster,” Heinz said. “And obviously the takeoff and landing are a little bit longer.
“Also, many people wanted a bigger engine. So we reinforced everything—everything is a little bit heavier—and the wings became a bit larger…and we mounted a bigger tail.”
With all the changes a Cruzer can see cross-country speeds of 115 mph or more, depending on the engine and propeller combination a builder chooses. The STOL variants cruise at around 80 mph.
Another goal for the Cruzer was to make takeoffs and landings behave more like traditional aircraft models. Regardless of the length of the field, STOL aircraft require certain techniques be used whenever departing or arriving.
One Week Wonder now looks like an airplane. As is the case with many projects, much is done, yet much is left to do.
Double checks of systems like avionics, electrical wiring, engine, brakes, and controls are complete. Final adjustments of the wing incidence, sweep, and dihedral are underway.
According to One Week Wonder Project Supervisor Caleb Gebhardt, fitting the wings is not difficult, but is a critical point in the build process.
“Its difficult in that you are dealing with a relatively delicate wing,” he said. “And until it is all on there, things can move.”
System testing will commence once the craft is out of the workshop tent and the wings are permanently attached. The project is on schedule to taxi under its own power as part of today’s air show.
The maiden flight of One Week Wonder may occur shortly after AirVenture 2014, but that will happen only when it’s truly ready.