Pilots will go to great lengths to fly airplanes they like. I went to the Czech Republic to fly the CH 701. That’ s a long way, and I did like the airplane. The experience tells a story of light-sport aircraft development that may become increasingly common.
Like most light plane pilots, I’ve long been familiar with the designs of Swiss-born engineer Chris Heintz. His many aircraft models have put some 2,000 builders in the air. The low-wing, Piper Cherokee-like CH 601 is far and away the most popular air plane he’s designed, with it representing more than 60 percent of all Zenith models sold. Yet, perhaps the most distinctive-looking design he’s offered is the short takeoff and landing (STOL) capable CH 701, the subject of our discussion this month. Now the world grows smaller with Heintz’s Canadian designs being manufactured in the Czech Republic and freighted to the United States for fun in the sky.
Old Country Flying
My travels to Eastern Europe following Aero 2003 brought me to the Czech Republic, some 300 kilometers south of world-famous Kiev, to the lesser-known town of Stare Mesto in the Republic. This is where American Chip Erwin has set up shop to fully manufacture the designs of Chris Heintz. His business is called Czech Aircraft Works, abbreviated as CZAW, “CZ” being the two-letter symbol for the Czech Republic. After arranging a license agreement with the Heintz family to build Chris’ designs, Chip tapped into the Czech Republic’s supply of highly educated and well-trained aviation workers. Following the collapse of communism and the evaporating inflow of money from the Union of Socialist Soviet Republics (USSR), several major Czech aircraft builders fell on hard times. Their employees were happy to go work for a Yankee entrepreneur who wanted to build light airplanes and send them to Western Europe and the United States.
Sebastien Heintz, one of Chris’ four sons, runs Zenith Aircraft Co., based in Mexico, Missouri, and it sells only kits. CZAW’s mission, then, is to build completed airplanes for sale in Europe|and eventually in the United States when proposed special light-sport aircraft (LSA) category is finalized to allow ready-to-fly aircraft to be sold in this country.
That plan now includes a company called SkyShop. Based in Stuart, Florida, SkyShop is already assisting some United States customers who are electing to purchase kits from CZAW. These builders then travel to the Czech Republic and work on their airplane with assistance from factory personnel there. It’s a great opportunity to be involved in all facets of construction of the airplane and have a wonderful travel experience at the same time. (As Zenith has demonstrated at air shows, building a CH 701 or 601 can be accomplished in a week, albeit a busy one with long hours.) After the owner/builder returns to the United States, his or her completed aircraft is disassembled and shipped to Florida where SkyShop assists the builder in reassembling the aircraft and making the first flight in it.
When the light-sport aircraft rules are finalized, establishing the more lenient kit-built experimental LSA category and the ready-to-fly special LSA, CZAW will be ready to ship air-planes as soon as the design can show conformance to the consensus stan-dards that FAA has mandated each aircraft design must meet.
More Than 25 Years of Flying Fun
Chris Heintz’s CH 701 was first in-troduced in 1986 “as an off-airport, short takeoff and landing kit aircraft.” It was intended to address the desires of pilots who fly for fun and recreation, yet Chris wanted it to be a project first-time builders could successfully undertake.
“The STOL CH 701 was not designed to be just another pretty light aircraft,” said Chip Erwin. “It was engineered to “We’ll have the capability to build 300 aircraft in 2004,” said Chip, as he explained a plan to move into new quarters as soon as a prior tenant clears out.
Chris Heintz’s CH 701 was first introduced in 1986 “as an off-airport, short takeoff and landing kit aircraft.” It was intended to address the desires of pilots who fly for fun and recreation, yet Chris wanted it to be a project first-time builders could successfully undertake.
“The STOL CH 701 was not designed to be just another pretty light aircraft,” said Chip Erwin. “It was engineered to offer outstanding short takeoff and landing performance, all-metal durability, and unparalleled ease of construction.” It combines the construction methods of conventional aircraft with the short-field capabilities of an ultralight aircraft. The CH 701 features fixed leading-edge slats for high-lift, full-span flaperons (both ailerons and flaps), an all-flying rudder, and well-proven all-metal construction.
Using an architectural metaphor, the STOL CH 701 is form following function, Chip explained. “It looks like a Sky Jeep, which is what it’s often called by its owners.”
And, the Sky Jeep excels in short-field performance. The CH 701 I flew, powered with a 100-hp Rotax 912S engine, was airborne in less than 100 feet of asphalt runway. Rotation comes barely after you apply full throttle, and liftoff begins at 25 mph (as indicated on the airspeed indicator). The CH 701 literally leaps into the sky within four seconds from standstill. Naturally, head wind will further shorten both the time and distance for takeoff . In a word: impressive:
Working the Design
CH 701s and CH 601s are built in roughly equal numbers by Chip’s CZAW operation. During my visit in early 2003, the company employed 85 production workers and 30 other staff members including engineers, quality control personnel, and administrative people. “We’ll have the capability to build 300 aircraft in 2004,” said Chip, as he explained a plan to move into new quarters as soon as a prior tenant clears out.
CZAW doesn’t simply churn out Heintz designs. In addition to airplane manufacturing, it has developed its own all-metal float system. Many Americans have seen these convention-ally made floats in both straight and amphibious gear at air shows around the country, but they may not have re-alized the floats hailed from the Czech Republic.
CZAW also builds the wings and tail sections for the Part 23-certificated OMF Symphony in a shop that is sepa-rate from the Zenith production line to meet the requirements for FAA certifi-cation. On my visit I saw parts for several Symphony 160s under con-struction.
To feed the production machine, Chip imports literally tons of aluminum sheet, steel, and other parts, much of it coming from the United States. This can set nervous American buyers at ease regarding trade deficits. Most instruments are also built in the United States. Fiberglass parts like the nose cowl are locally built in the Czech Republic.
Get in and Go
Entry into the CH 701 is simple; step in front of the strut with the door opened up wide against the bottom of comfortable, the wing and merely sit down and swing your legs in, though I helped pull my feet with my hands to clear the front cowl post.
The door closes with a single latch that’s located at approximately your outside knee. On opening, a friction latch props the door open securely.
The CH 701 seats are comfortable, and the interior is nicely finished with carpeting, protected for the customer during my test flight with plastic just like at an auto dealership. Shoulder belts are standard on both seats, and they’re made in the United States, too. My flight-test aircraft was equipped with instruments set up for American sale, so I was right at home with feet and miles per hour indicated on the gauges. Obviously, for European consumers, the gauges feature meters and km/h readings.
I loved the great visibility out of the top skylight. It’s quite useful in turns opposite the side on which you’re sit-ting. On your own side, you’ll have to look out the side window before turn-ing.
While visibility from the CH 701 is not as wide as the company’s clear-canopy CH 601, it was more than adequate. Of course, the design offers the wonderful downward visibility of all high-wing aircraft that many pilotsprefer for aerial sightseeing. Flying over medieval castles in the Czech Republic, I was pleased with the great viewing platform the CH 701 offered.
However, despite the wide cabin, a cross-member overhead sometimes bumped my headset, suggesting that helmets might be uncomfortable for anyone but shorter occupants.
The CH 701’s instrument panel switches were easily reached, and the instruments were easy to read. The panel offers adequate room for a variety of instruments and radios. When I ob-served the production line in operation, CZAW was even equipping one aircraft with an autopilot.
Chris Heintz’s signature Y-shaped joystick handle worked well to my side (in the left seat), but I found it a bit more awkward to the right. With a right-seat occupant, I found motions to that side bumped into the other per-son’s leg. The left side of the stick was equipped with multiple switches for trim control and radio transmit. The Y-stick should work excellently for training and allows more legroom than dual joysticks; however, it does offer er-gonomic challenges compared to a side or center stick.
In my test CH 701 the throttle kept creeping forward, a problem I had to keep in mind. An adjustment should fix this, though it might pose a prob-lem for a student; otherwise, the 701 is a good choice for a training aircraft.
Powerful hydraulic brakes slowed the 1,100-pound aircraft well, and the landing gear has generous ground clear-ance for off-field landings. The CH 701 slab gear has a reputation as being ex-tremely stout. Thankfully, I never tested its ability.
When you open the throttle of a 100-hp CH 701, be prepared for action. Much like a Quicksilver, its ground break is extremely fast on takeoff. This is a central feature of the design. Its leading-edge slots and full-flying flaper-ons were created to provide fast liftoffs from unimproved airstrips. Believe me, the machine works!
Takeoffs were easy if you were pre-pared. Landings took a bit more finesse, though the airplane can handle fairly rough touchdowns.
I found it necessary to keep the stick aft to prevent bobbing up and down. My checkout pilot, Mark, said the wing tries to start flying again unless you keep the angle high. Once you’ve started to raise the nose in preparation for final touchdown, you need to keep it up. The wing can fly so slowly that lowering the nose a bit makes the 701 think you want to resume normal flight.
Approaches to landing were made at 50 mph with a bit of power, though it was obvious that I could come in much slower once I was ready for the plane’s unique low-speed performance characteristics.
If you fly from unimproved, short, or soft airstrips … the Sky Jeep may be your dream plane.
The flaps were difficult for me to fully deploy. I could get enough flaps down for landing, but I needed a better technique to get the flaps all the way down. To deploy the flaps you reach down (near where a seat adjustment might be) and pull forward, an awk-ward motion that I could only manage to the first notch.
Fortunately, sideslips were very ef-fective in either direction, thanks to the slab-side finish of the design. Standard large tires make off-field landings no problem.
Scrambling Into the Air
The CH 701’s climb angle, expressed as deck angle, is very steep, yet this is not unreasonable as the fixed-slat wing provides genuine STOL characteristics. I measured climb, with the 912S, at bet-ter than 1,000 fpm dual and nearly 1,500 fpm solo. All measurements were done at about 1,000 MSL on a wintery day of about 20°F.
I cruised at near redline, about 105 mph, thanks to that engine. Frankly, I found it too much engine for the plane, and Chip readily agreed. However, he indicated that it was the right engine if you use amphibious floats.
All the pilots out at CZAW’s nearby airfield agreed that the 701 has a high sink rate. This may be good for getting into tight fields, but Mark didn’t want to be too low while away from the air-port. He told me, “At 1,000 feet AGL, we’ll be on the ground in 60 seconds.” Later trials showed the 1,000 fpm sink rate to be about right, despite the high-lift wing.
In other testimony to its superior low-speed performance capabilities, a CH 701 has been configured to tow hang gliders in Germany. These aircraft prefer tows below 30 mph, and the 701 can do it. The low stall speed and excel-lent climb performance of the aircraft make the CH 701 an ideal tow plane for the slow-flying hang gliders.
As is often the case, I got to fly a brand-new plane. Consequently, all the pulley wheels and linkages were still a bit tight, which made the 701 rudders feel rather stiff. They tended to stay where they were put, which gave false impressions of handling. I once thought the plane had a tendency to-ward a left turn (from the ball’s position), only to realize that I had the rudder slightly depressed from a previ-ous maneuver. Such tightness will loosen in time and won’t be an ongo-ing problem.
Contrasting the rudders were very responsive ailerons, virtually regardless of speed. When I flew at a low (though probably not minimum) speed, roll pressures seemed almost as light as at cruise speed.
My Dutch roll coordination exer-cises were sloppy owing to the stiff rudders. At speed, very little rudder is needed, while at slow speeds more is needed (logically).
A medium-power stall did break and went rather sharply to the right siderapidly enough that Mark flinched toward the controls. Despite the abrupt maneuver, recovery was easy. One fac-tor affecting this behavior may have been the powerful engine and a prop set up for fast climb. Stick with the 80-hp engine and a medium performance prop, and you may never experience a sharper break.
Low-power stalls never broke and were extremely well behaved. With stalls coming at nearly 30 mph and with top cruise speed at nearly 100 (in the 100-hp, 912S-powered version), you have a wide speed envelope of bet-ter than 3-to-1.
Ready for a Long Trip?
The CH 701 probably won’t be your ideal cross-country cruiser; it wasn’t de-signed for that kind of flying. Rather, the CH 601 will prove much better for that realm of flight. But if you fly from unimproved, short, or soft airstrips, the Sky Jeep CH 701 may be your dream plane. Like many four-wheeled vehicles or SUVs, the CH 701 may not be the prettiest airplane on the ramp, but it’ll take off from that ramp faster than al-most any other airplane. Lots of sport pilots enjoy such gutsy capability.
Zenith reports more than 500 CH 701s are flying around the world. Many of these are kit-built, but a growing number are emerging from the Czech Republic. When the sport pilot/light-sport aircraft rules are finalized, the number of airplanes coming from CZAW’s Stare Mesto plant is sure to in-crease sharply.
Indeed, CZAW is gearing up for that reality. Last month, Chip confirmed that he was expanding the company’s manufacturing space by 50 percent, mostly to double the 701 production. “We shipped 30 percent more aircraft in 2003 than we did in 2002, but we still cannot keep up with sales. The 701 was introduced in 1986, and sales are still stronger than ever,” he said. Per-haps Sky Jeeps simply do not lose their appeal.
The CH 701 should easily fit the pro-posed light-sport aircraft consensus standards. Chris Heintz and his sons, Sebastien and Nicholas, have partici-pated in the ASTM standards-writing efforts. Their aircraft should meet the standard easily, and because CZAW builds true to the original design, so will its aircraft.
Even though it is only handsome in the way of a Hummer, the CH 701 en-joys a good reputation for its durability and outstanding STOL performance. Recently, I drove behind a Jeep that sported a three-foot-wide bumper sticker across its rear window that read: “It’s a Jeep thing. You wouldn’t under-stand.”
If you’re a CH 701 buyer, you’ll likely understand. And you can fulfill your dreams today.
|Empty weight||580 pounds|
|Gross weight||1,100 pounds|
|Wing area||122 square feet|
|Wing loading||9.0 pounds/square foot|
|Useful Load||520 pounds|
|Payload (with full fuel)||400 pounds|
|Cabin Interior||41 inches at shoulder|
|Fuel Capacity||20 gallons|
|Baggage area||40 pounds, cabin shelf|
|Kit type||Construction kit|
|Build time||350 to 400 hours|
|Standard engine||Rotax 912|
|Power||80 hp at 5,800 rpm|
|Power loading||13.8 pounds/hp|
|Max Speed||95 mph|
|Cruise speed||80 mph|
|Stall Speed||30 mph|
|Never exceed speed||110 mph|
|Rate of climb at gross||1,200 fpm|
|Takeoff distance at gross||90 feet|
|Landing distance at gross||150 feet|
|Range (powered)||400 miles – 5 hours|
|Fuel Consumption||about 4.0 gph|
|Standard Features||80-hp Rotax 912, with electric starter, stainless steel exhaust, radiator, and 3-blade Warp Drive prop; dual 10-gallon fuel wing tanks (20 galoms total); wide, dual doors; independent hydraulic brakes; mechanical flaps; 16-inch tundra tires, removable wings (also see options); complete engine instrument package (Rotax); fully enclosed cabin; in-flight trim; sturdy single piece landing gear construction; steerable nosewheel; all-metal wings, tail, and fuselage; seat belts with shoulder harness.|
|Options||100-hp Rotax 912S (as tested) and several other engine sizes and brands; additional fuel tanks (40 gallons total); electric trim; folding wings; amphibious or straight floats; cockpit-widening “bubble” doors (add six inches of effective cabin space and more visibility); navigation and strobe lights; cabin heat (with Rotax engine); additional instruments.|
|Construction||All-metal airframe, wing, and tail; many skins predrilled; factory-riveted wing spars and lower cabin frame sides; fiberglass fairing. Kit components made in the USA; sold by U.S.-owned company.|
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros – Short takeoff and landing (STOL) design uses fixed slats to achieve excellent performance. Highly functional aircraft; can operate easily from short, unimproved strips. More than 20 years of field experience with more than 700 CH 701’s flying.
Cons – If you’re looking for sleek or pretty, the CH 701 isn’t your bird. Not fast enough for regular, long cross-country flights. Available only in kit form at present (though cost is therefore lower). Builder remains the “manufacturer” indefinitely.
Subsystems available to pilot such as: Flaps; Fuel sources; Electric start; In-air restart; Brakes; Engine controls; Navigations; Radio; (items covered may be optional).
Pros – Flaps, trim, electric start, differential brakes are all standard on the CH 701. Fuel (20 gallons standard) contained in the wings, away from occupants. Engine access through easily removed cowling. Generous useful load allows adding optional equipment without losing utility.
Cons – Flap handle proved challenging for me to deploy to the last notch (though this may have been a fact of the new, test aircraft). Trim control located only on left half of stick. Flap position must be checked via lever position or visual; no indicator (though builder could add it if desired).
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros – With “bubble” doors, the CH 701 is adequately roomy for all but the largest occupants. Baggage space in hat rack position. Very easy entry through wide doors; good for larger or less flexible occupants. Shoulder belts standard. Doors secure well. Reach to panel is good.
Cons – Cabin is modestly wide compared to many LSA (though “bubble” doors add effective width). Center joystick tended to hit right-seat occupant in flight (though I was deflecting more than most normal inputs). Interior is rather Spartan unless builder elaborates.
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros – Strong, differential brakes aid ground handling. Gear and structure can handle fairly rough terrain. Skylight adds good upward visibility for traffic checking prior to takeoff. Landing gear easily able to handle fairly rough terrain. Good ground clearance.
Cons – Lateral visibility is less open than in the bubble canopy CH 601. Test aircraft had brakes only on the left; going dual will add some cost and weight. No other ground handling negatives.
Qualities; Efficiency; Ease; Comparative values.
Pros – Takeoff is very rapid and requires a very short distance, perhaps the model’s top attribute; ground roll is only 100 feet and rotation starts almost immediately, thanks partly to leading edge slats. Approach speeds can be very slow with practice, good for the shortest field landings.
Cons – Landings have a slight challenge that demands a little practice; you must keep the nose up once lifted or the CH 701 merely resumes flying. Sink rate after power retarded is quite high (1,000 fpm); this is a useful design feature allowing STOL landings, but you have to anticipate.
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros – Aileron forces were very pleasant and responsive. Efficient rudder control surface, a full flying design (but see “Cons”). Pitch forces were light without being sensitive, a good combination. Control forces at very low airspeeds permitted by wing/slat design were reasonable.
Cons – Control harmony hard to check in test aircraft as rudders were still tightly adjusted; tended to stick slightly (though possibly only on this aircraft). Wing can fly so slowly that controls necessarily become more sluggish due to low airflow.
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros – Terrific takeoff performance, better than all but the very lightest ultralights. Climb very strong at 1,000+ fpm at gross. Very capable airplane for low-and-slow flying over landable terrain; extremely slow speeds (in the 30s) with practice and caution.
Cons – Rather high idle thrust sink rate (1,000 fpm); neither glide is very long (though this is considered a deliberate design feature for a STOL airplane). Cruise speed of 80 mph won’t carry you too far. Fuel at 20 gallons standard is four hours or less (though sufficient for most operations).
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros – Mild stalls at most angles and speeds (though see “Cons”). Longitudinal and lateral stability appeared very normal in all tests. Response to power input/decrease from trim flight was positive and predictable with few oscillations.
Cons – Stalls with the 100-hp CH 701 (as tested) can be done aggressively enough to cause a sharper break (though recovery remains quick and simple). Adverse yaw was quite significant, something to be remembered at very low speeds the CH 701 can achieve.
Addresses the questions: “Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?”
Pros – Longtime, well-proven supplier (est. 1992) gets excellent comments from customers for technical support and customer service. Can be flown by Sport Pilot certificate holder. Can get airborne with good basic equipment for about $35,000 (and 400 hours of your labor), far less than many light sport aircraft.
Cons – Not a Special- or Experimenta light-sport aircraft (yet), so Amateur-built rules mean builder always remains the “manufacturer,” with attendant legal responsibility. Build time is 350 to 400 hours (though factory support can ease the burden). Even $35,000 is more than some ultralight kits (though with 4-stroke engines, it will be closer).