Well, here I go, embarking on another great adventure. You're invited to look over my shoulder as I build a Hawk II Arrow.
My name is Steve Bensinger; I now live near Lakeland, Florida (the home of Sun N Fun). When I began this project I lived in the Ann Arbor, Michigan area. I've been flying ultralights since 1984. The Hawk will be the fourth plane I've built; the first one was a 1984 Teratorn Tierra (now sold by Golden Circle and called the T-Bird), the second was a 1993 RANS S-4 Coyote, and the third was a 1996 Arnet-Pereyra Aventura II seaplane. You can see the Aventura building process at my Building an Aventura II web site. I have since built yet another plane, a single seat Hawk Sport, which you can see here.
CGS Aviation of Broadview Heights, Ohio USA (near Cleveland) manufactures the Hawk line of light single and two seat planes.
The following information defines what ultralights are in the USA, and gives a little background on ultralight construction and powerplant choices. Or if you like, you can skip the fluff and start building!
It also qualifies under FAA's "51 percent rule" to be registered as an Amateur-Built Experimental aircraft.
This plane's design and construction use the same materials and design
concepts as many current light plane designs. Much of what you see here is
similar to other popular models from RANS
(the Coyote and Airaile models), Quad
City (the Challenger), Flightstar,
Quicksilver, and many others.
This airframe of this kit consists of aircraft quality aluminum tubing
and fittings bolted and pop-riveted together using aviation-grade fasteners.
The wing and control surfaces can be covered with heavy-duty dacron cloth,
much like what is used with boat sails - or with dope and fabric, a process
that uses a special heat-shrinkable polyester cloth and special paints that
seal and protect the cloth. I picked the dope and fabric process for my
The engine I originally planned to use was a 52HP, two-cycle, two-cylinder, air-cooled
powerplant sold by Rotax (a subsidiary
of Bombardier) of Austria. It incorporates two Bing slide-type carburetors,
a dual CDI ignition system (two spark plugs per cylinder), and a gear reduction
system at a ratio of 2.58:1 to drive the prop. By the time the kit was finished I ended up installing a Rotax 582, a 65HP two cylinder, two cycle water cooled powerplant with a 3:1 gear reduction.
Does Bombardier sound familiar? Originally these engines were designed to drive water pumps, then were redesigned for snowmobiles, and lately are being used in personal watercraft. The engine used here has been specifically designed by Rotax for use in light aircraft. They have a very high power-to-weight ratio, mostly due to the fact that they produce power on every piston stroke, as opposed to four-cycle engines which produce power on every other stroke.
There has always been concern about the reliability of two-cycle engines because they work harder than a comparable four-cycle. However, with proper maintenance they can be very reliable. This means you have to either be knowledgeable about your engine, or have the money to pay somebody else to maintain it. These engines do not have to be babied, but they do need to be properly maintained, or you will have an engine failure. Of course, that applies to any engine!
|Aero Sports Connection|
|United States Ultralight Association|
|Experimental Aircraft Association|