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The popularity of
the STOL CH 701 aircraft and other Heintz designs around the world has created many imitations and copies. These
copies are often modified versions of the original STOL CH 701, and are not authorized by
designer Chris Heintz.
The following photos were all found on the internet. Let us know if you come across a design that has an uncanny similarity to a Chris Heintz design...
Note: Copies of the original design may not be eligible for registration as "amateur-built" or other category aircraft. Just because they look like a STOL CH 701 does not mean that they are.
In the April 2007 issue of Recreational Flyer, the magazine of the Recreational Aircraft Assoc. of Canada, editor Gary Wolf points out that: "Heintz is nearly alone in selling construction plans these days, while most manufacturers concentrate on selling kits and completed aircraft. The photocopier is the worst enemy of every designer, and Heintz's 601 plans have been copied and "improved" by manufacturers around the globe. Have a look at many of the recent bumper crop of Eastern European light sport aircraft and you will see how many have their roots in the Zodiac. Some look very tempting, but the question must be asked where a buyer might find parts and support five years hence. A [Zenith] Zodiac owner gets full construction plans and a mature manufacturing company as his backup"
Following is the translation of an editorial from the French magazine EXPERIMENTAL/FOX ECHOS, May/June 2000 issue. It addresses the issue of R&D* we are experiencing more and more.
"Chris Heintz and sons, designers and manufacturers of the Zodiac CH 601 and STOL CH701 series of aircraft (built from plans only, from partial or from complete kits by homebuilders), are getting less tolerant of supposedly "improved" pirated copies of their designs. Zenith Aircrafts internet homepage recently added a new link identifying rebel copies of their aircrafts originating from Brazil, Poland and Italy. The company has been sending updates and cautionary notices to the aviation press on a regular basis regarding these "new" machines, clearly derived from the CH 701 or CH 601, clearly unauthorized.
"The principle cause spurring the spread of these copies on the new light-plane market is not just the undeniable success of these two designs now commonly registered as ultralights in many countries. A prime contributing factor has been the availability of complete blue-prints and assembly manuals for all components aircraft in question from Zenith Aircraft. This intentional move by Chris Heintz has allowed hundreds of aviation enthusiasts around the world to build and fly their own aircraft, on a budget.
"Making these construction plans available, while not profitable, was a generous move by Heintz in "the spirit of homebuilding". It is also having dire commercial repercussions: The designers gesture has now been dishonored and misused by a number of unscrupulous manufacturers who, by their very actions, attest to their own inability to conceive and engineer their original aircraft. Naturally, each of these nevertheless had the expertise to then "improve" on the original design.
"The motivation for the modifications has been varied: Changes to avoid "copyright" infringements; advanced or complete assemblies to meet market demands (ready-to-fly, custom modifications, etc.); and "improved" performances, often sadly based on strokes of ingenious intuition by novice builders not yet fully aware that every airplane is a sum of compromises
"Chris Heintz engineers his airplanes to well-known stringent standards. Every component and flight characteristic is conceived to work in harmony with the whole from the outset. The wings, fuselage and tail; the controls, the cabin and the rest form that whole which can be appreciated in its entirety. Modify just one, let alone several, of these elements without reviewing the whole and clearly, the machine as a unit will have been tainted "
The January 2000 issue of EAA Experimenter says:
In a letter to Ultraflight magazine, Sebastien Heintz, president of Zenith Aircraft Company wrote:
approval of the Savannah (!).
ICP's Savannah is nothing more than a modified copy of our popular STOL CH 701 aircraft. In fact, ICP of Italy (www.icp.it) was a one-time distributor for the STOL CH 701 in the eighties (and alsomarkets an unmistakable copy of our ZODIAC CH 601 design called the Amigo) and a closer examination of the similarities of the design and the construction techniques shows the Savannah to be more than a "derivative" of the STOL CH 701 - copying the design and simple construction techniques that designer Chris Heintz has painstakingly developed over the past 30 years.
As the article points out, the Savannah has been on the market for years without ever having undergone spin testing: Companies that copy an existing design typically do so because they lack engineering skills, and to profit from an original product's hard-won reputation. Modifications are marketed as "improvements" over the original design, but often these modifications are not properly engineered andtested, as the above demonstrates.
With form following function, the STOL CH 701 was not designed to be just another pretty light aircraft, but was engineered to offer outstanding short take-off and landing performance, all-metal durability, and simplicity and ease of construction. The design features fixed leading-edge wing slats for high lift, full-span flaperons (both ailerons and flaps), an all-flying rudder, andsimple, yet durable, all-metal construction. Introduced in 1986, the STOL CH 701 design has been a success since the beginning because it met its design goals, and continues to be very popular aircraft kit today as it meets the needs of sport pilots seeking the features and advantages of a "real" airplane with the short-field capabilities of an "ultralight" aircraft.
The success of the design and its ease of construction have made it what is probably the most copied kit aircraft design on the market today. We count six different copies currently being produced and marketed around the world. Admittedly, we've made it easy for copiers by offering detailed blueprints (and not just assembly instructions), but we feel that this is an important service to the otherwise very honest aircraft-building community.
In flight testing the Savannah, Gratton notes that the take-off and landing performance of the aircraft is 500 ft. and 460 ft. respectively, with climb at 600 fpm and cruise at 80 mph. These performance figures are notably inferior than those for the STOL CH 701 - an indication that the Savannah's modifications adversely affect performance, not to mention flight characteristics.
While imitation may be a form of flattery, outright copies of a proprietary design is a form of theft, and they are typically misrepresented to buyers. We're concerned that such copies do not meet original design specifications (quality of raw materials and hardware, manufacturing standards, etc.) and that modifications may not, and often appear not, to be properly engineered (usually you decide to copy when you don't have the engineering ability to create your own design). Potential buyers need to be aware of this, and should be concerned about the level of technical support and spare parts available from these foreign manufacturers, and whether the imported kit will be eligible for registration in the "amateur-built"category.
Designers and manufactures get ideas and "inspiration" from the competition in the ongoing quest to design and build better aircraft (in fact, Chris Heintz, an aeronautical engineer by training, often consults to competitors), but I think you'll agree that copying someone else's work outright (and then marketing it as an "improved original design") is not acceptable business practice and does notserve the aviation community. Openly promoting a known copy of an original design, as this article does, is a disservice to the aviation community, and penalizes the engineers and companies that keep this industry vibrant by developing, manufacturing and supporting unique light aircraft designs.
Notes / Additional Information:
Details about the unique STOL CH 701 design features:
(In 2001, the design gross weight of the STOL CH 701 was increased to 1,100 lbs. from 950 lbs. by redesigning the wing spar and numerous other structural components. Nearly overnight, copies were subsequently marketed with a gross weight increase to 1,100 lbs. - with no apparent design or structural changes to justify the gross weight increase).
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© Zenith Aircraft Company: 2013-05-06