Dimona DV 20 Katana

A lanky Austrian comes to the U.S. training market.

Primary flight training can be, and should be, a rollicking good time. For it to provide the equivalent of the "every day's a mid-term" blues forgets completely the tenet that something worth doing well is an endeavor well worth grinning about. A dour, serious aeronautical education serves not only to sap the joy from this magic called flight, but also to steepen and roughen those inevitable hillocks enroute to the private ticket.

Though we aim to imbue an air of exhilaration into the long list of do's and don'ts, we find ourselves at odds with the very airplanes charged with transforming ground-pounders into — what the occasional onlooker still mentions breathlessly — pilots. To put it bluntly, our collective fleet of Cessna 150s and 152s, Piper Cherokee Flite Liners, and their ilk, is dull. That's right, boring. They have all the sex appeal of a crate of string beans. Not only that, they're old and getting older. Plus, a good many of them display their age and hours in ways off-putting to the pool of newcomers to flying — ragtag plastic interiors and oil- canning skins.

There is hope. Aerospatiale in the past three years has brought to the flight schools its trainer member of the Caribbean family, the Tampico, which hardly looks the part of basic trainer. Now comes another round, courtesy of new certification rules — the Quicksilver GT-500, a simple, inexpensive near-ultralight (" Quicksilver GT-500," November 1993 Pilot), and the Zenair CH 2000, a somewhat quirky-looking (but conventional-flying) two-seater from Canada (" Zenair CH 2000: Zen and the Art of New Trainers," December 1993 Pilot). Add to that list the Dimona DV 20 Katana.

Derived from the Hoffmann Super Dimona motorglider, the Katana, named after a Samurai warrior's sword, is defiantly sleek and unconventional. Smooth fiberglass skin contrasts with the pimply metal of the usual trainer, and the Katana's wasp waist gives it a vaguely organic profile. So far, according to company representatives, the DV 20's uncommon looks haven't turned off prospective clients; to the contrary, many cite it as a major attraction.

This curvaceous model will have to rely upon more than its good looks on duty with training schools around the country, so it has been thoroughly massaged for the role by HOAC (Hoffmann Aircraft in Austria) and by its U.S. distributor, Dimona Aircraft USA, based near Denver. (The maker is also aware of the trouble-prone lookalike Piper Tomahawk and says its will take all steps necessary to see that the Katana gets glued together correctly, the first time out.)

In the transformation from motorglider to trainer, the Katana's wings were clipped from the Super Dimona's 53-foot wingspan to the present 35-foot span. The main spar box and the quick-detach mechanisms, however, remain. The Super Dimona's conventional gear gives way to a tricycle configuration with spring-steel main gear legs. Up front, the third wheel is free castering and offset slightly to the left to clear some under-cowl structural members.

At the behest of the U.S. distributor, Hoffmann painted over some of the bubble canopy's clear plexiglass. This should make the Katana more habitable in torrid desert summers. For operators concerned about the airplane's composite structure remaining firm in thermometer-busting climes, Dimona is prepared to offer a written, 12,000-hour airframe guarantee.

Retained from the Super Dimona (and the element setting that model apart from the garden-variety Dimona) is the Rotax 912 four-cylinder engine of 80 horsepower (" Airframe and Powerplant: Engines Emerging," November 1993 Pilot). This certified version of the 912 — like the experimental-class models — employs liquid-cooled cylinder heads, air- cooled cylinder sleeves, dual-plug electronic ignition, and a gear reduction drive. In the Katana, the 912 spins a Hoffmann constant-speed propeller, itself an interesting laminate of wood core, nickel leading edges, and an overall fiberglass wrap. What's this? A constant-speed prop in a trainer? Yes, the Katana will require a bit more effort on the part of the student pilot to learn and manipulate the prop lever, but as recompense, there's no mixture control to mismanage, thanks to the Rotax's self-compensating dual Bing carburetors. The propeller choice stems from an attempt to eke better climb performance from an airplane that weighs as much as a Cessna 150 but which has 20 fewer horses under the hood.

Taking full advantage of a laminar-flow wing, slightly reflexed flaps and ailerons, and beautifully tapered fuselage, the Katana sports mostly excellent numbers, considering the power. Cruise speed is listed as 125 knots (we can vouch for a GPS-noted 122-knot cruise at 75-percent power and 6,500 feet) and a flat-out run of 135 knots.

Still, there's no fooling gravity, even for a moment, when it comes to the climb. Eighty horses lifting more than 1,600 pounds proves at best an uphill battle. The factory lists a maximum-weight sea-level climb at 730 feet per minute, on par with the Cessna 152; power loading of the Katana is 20.1 pounds per horsepower, compared to the 152's 15.7 lb/hp. In the Katana, we seldom witnessed much better than 600 fpm in the climb from near sea level, even with the airspeed indicator's needle pegged on the best-rate speed 65 knots. By 6,500 feet, the Katana is down to 400 to 500 fpm, even with full throttle and maximum-continuous engine rpm. Despite Dimona Aircraft's assurances that the airplane has been tested in high temperature and altitude conditions, we remain skeptical that the Katana will have enough oomph for, say, a Colorado Springs flight school.

Another indication of the Katana's modest motivation is the need for flaps on takeoff. Preselected positions include 15 degrees for takeoff and approach and 40 degrees for landing. Sure, you can perform no-flap takeoffs, but you'll eat up more runway than the listed 1,600 feet to get over the 50-foot obstacle, and the initial climb will be far from energetic. None of the Dimona's climb characteristics should surprise anyone remotely familiar with Sir Isaac Newton's work — 80 hp can only do so much.

Indeed, once up to operating altitude, the Katana scythes through the air exactly like its namesake. You can pull the prop lever back to attain a quiet 2,300 rpm (equivalent of 5,300 engine rpm) for cruise and scoot up to 120-plus knots. Try that in your 150. Enjoy also fuel economy foreign to the Continental- and Lycoming-engine trainers. The factory claims 3.2 gallons per hour as a "best fuel consumption" figure. According to the engine manual, count on a bit over 4 gph at 75-percent cruise; that's a substantial improvement over the usual Cessna 152's average 6 gph fuel burn. The Katana should run for about five hours' total endurance from the 20.9-gallon fuselage tank, itself an aluminum structure located below the baggage shelf. Many potential customers bemoan having fuel in the fuselage, but Dimona assures them that the airplane meets the latest crashworthiness standards. In any event, placing fuel in the wings would call for a substantial redesign, and it's a bit too late for that.

Cruising around the countryside hardly represents the classic training mission, though; in the more typical around-the-pattern duties, the Katana performs admirably. Control forces and responses are conventional and predictable; in a perfect world, the Katana's ailerons would requite less effort and would have a smidgen more power. The control stick stands tall from the cockpit floor, and although you're tempted to grasp its upper limits to fling the DV 20 into a wing tip, you'd be better holding on a bit lower to better manipulate the light elevator. This is not the classic control harmony because the Dimona is significantly lighter in pitch than in roll, but it works well enough.

Those with a memory of the Beech Skipper or Piper Tomahawk often bristle at the sight of the Katana's T-tail. Worry not. The configuration is well implemented here. On the takeoff roll, it is possible to lift the nosewheel easily by the time the airspeed needle comes off the rest, and there remains sufficient pitch authority, even during a too-slow, near- zero-energy landing. What's more, thanks to pushrod control linkages, the Katana's elevator is unusually communicative. After a few hours in the airplane, you'll notice the stick feeds back exactly what is going on some 15 feet aft. Indeed, this is an obvious leftover from the Dimona's motorglider days, and sailplane pilots will probably recognize this characteristic. Unlike a sailplane, however, the Katana has virtually no adverse yaw, and most maneuvers can be accomplished with little or no rudder input.

In the training environment, the Katana will coddle its students during the stall series. In power-on and power-off situations, the stall amounts to a vigorous bobbing of the airplane's nose, with recovery just a slight relaxation of back-pressure away. Even when pressed, the Katana's stall behavior is more benign than a Cessna 152's.

Much of the primary training syllabus centers on takeoffs and landings, and in this regime, the Katana is a sweetheart. You may find yourself flying the first pattern a bit fast, since the Katana accelerates quickly on the downwind if you leave climb power in. When you reduce power to get to the 80-knot flap speed, you notice that it settles on a slightly nose-high attitude in the clean configuration. (This is perhaps more noticeable in the Katana because forward visibility is otherwise so good.) Drop the first notch of flaps (15 degrees), and the nose comes down; there's little pitch-trim change. Favored approach speed is 65 knots, and that works well if you remember to get slowed down early. This airplane is slick, and you'll find the throttle will be all the way back trying to slow down and come down. Plan to save the full-down flap setting for short final because the amount of drag developed by 40 degrees of flap is considerable; this serves to dramatically steepen the approach and scrub a good 15 knots off the airspeed. Our so-called perfect world would see a third preselect around 30 degrees, or perhaps infinitely variable flaps. Landings themselves are simply accomplished and surprisingly bounce free on the spring-steel gear.

One other nit we found during the pattern work concerns the Katana's trim adjuster. It's a lever located on the center console, aft of the throttle quadrant, its position fixed by a small pin. You must pull up on a small knob before moving the lever. This arrangement proves unnecessarily fussy, making small and quick trim adjustments difficult. We have no idea why Hoffmann felt the need to reinvent the (trim) wheel.

When it is finally approved by the Federal Aviation Administration under the JAR-VLA regulations — the approval was expected this summer, but paperwork hangups have delayed certification — the Katana will be approved only for day-VFR operations. No approval for IFR flight is expected in the near future, given Dimona's (Hoffmann's) and the FAA's concerns about all- composite structures in terms of lightning protection. Stoddard-Hamilton Aircraft makes one of its Glasair models safe for lightning strikes by adding a layer of conductive material to the skins — a scheme also used by the mostly graphite Beech Starship — and that's something the Dimona's designers are considering for future models. Right now, however, the Katana, though ostensibly equipped for IFR with a full gyro panel and the requisite radios, must stay out of the clouds.

As you read this, Dimona USA expects a production line in London, Ontario, Canada, to be up and running, producing the composite airframes. Spares will likely be housed at the production facility, although Dimona USA is still considering setting up a parts supply in the States. The first 50 DV 20s off the line will sell for $89,500 with basic VFR avionics. Dimona USA says it will try to hold the line on prices after the first 50 have been constructed. In addition, the stateside distributor has made plans for some detail changes to the Katana, including more electrical power. (An additional full-time alternator is being considered, as well as coaxing Rotax to install a more robust generator pack, which currently puts out 24 amps.) Among the other slated changes: larger cabin- air vents, optional canopy tinting, a rearranged engine-instrument group, a shorter stick with a formed handgrip, map pouches on the cabin sidewalls, a larger oil- and coolant-tank access door, and a calibrated fuel-filler neck to facilitate partial fueling.

Though many these changes might be, we're certain little the company can do will steal any of the Katana's sex appeal. It's that element, assuming those cutting the checks in the flight-department procurement office vote the tiniest bit with their hearts, which will help the Katana. Right now, the DV 20's potential for low operating costs and durability must work against a rather stiff initial buy-in. In its defense, the Katana possesses that extra panache, the air of a bon vivant, to put it over the cost-conscious hurdle. If indeed — as the social critics curl their lips and say — sex sells, the Katana has a fighting chance.

Course Notes

We caught up with the Dimona Katana at the Central Missouri State University's flight school, where it was undergoing a series of flight tests by school administrators and flight instructors. According to Dr. Tim Brady, chairman and professor of Power and Technology at CMSU, the school, which has some 30 aircraft in its training fleet and about 600 students in the flight-training courses, has been looking for some time for replacement airplanes. At the time of our visit, Central had flown the Zenair CH 2000 and Cadmus Koliber, and was in line to test the new Grob trainers.

The school's pilots came away impressed with the Katana. "We thought it handled nicely, and was well-built. Frankly, we were prepared to be disappointed," says Brady, referring to the Katana's uncommon (for a trainer) construction materials and powerplant. "But we were not disappointed." Before they had a chance to fly it, some of Central's instructors questioned whether a stick-control airplane would be good for training. But, says Brady, after flying the Katana instructors quickly forgot about that complaint, "and besides, we know there's little gray matter involved in moving from a stick to a yoke."

That the Katana is not currently certifiable for flight in IFR conditions, Brady says is a short-term hindrance only. "We could use the airplane to teach IFR in VFR conditions, and the VFR limitation would only be a consideration if we were to replace the whole fleet with Katanas."

One problem Brady noticed was the Katana's lack of a mixture control. "The FAA makes us teach use of the mixture in primary training, so we would have to do that in another airplane."

Overall, Brady rates the Katana as "being very high on our list. The instructors liked it, and the mechanics liked the engine access and the quality of the structure." Dimona has also offered to send the mechanics to school to learn about maintenance and repair of the Katana's fiberglass structure.

If the ramp reaction by CMSU's instructors and students is any indication, the Katana will be a welcome addition to the fleet, should the school decide to purchase it. Of course, some of the enthusiasm might well be chalked up to Central's recent domination of the National Intercollegiate Flying Association's Region 6 competition. Central took top honors in most of the categories, and will go on to represent the region at the NIFA competition starting May 17 at Parks College. Taking some of the knowledge gained flying the various new trainers, Central will also host a training-aircraft symposium just before the start of the NIFA event, on May 16, also at Parks. — MEC