Used Aircraft Guide: Diamond DA20

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For efficiency, speed, view and handling, it's hard to beat. Just don't expect any IFR.

The world of training aircraft has all but reinvented itself since Diamond introduced the DA20 to the North American market nearly 20 years ago. When the Katana appeared, Diamond reasoned that the fleet of ancient Cessna 150s and 152s was growing weary and operators would lust for replacements. What it didn't anticipate was a couple of significant downturns, a glut of overproduction and the rise of the light sport aircraft market. The latter hasn't exactly set towering sales records, but it doesn't take many missed sales to turn a modest program into a struggling one.

Nonetheless, Diamond has still found success with the DA20 as a basic trainer and as an inexpensive, owner-flown fun flyer that's fast enough to fly the occasional cross country, albeit in VFR conditions only.

Flight schools say customers like the DA20 for its sporty looks and handling, reasonable costs and expansive views from the airplane's unique bubble canopy. Although many of those customers might not realize it, there's something else to like, too: The DA20 has one of the best safety records in general aviation, hands down and with no asterisks. But if many buyers put safety at the top of their list of considerations, it appears not to have helped DA20 sales much. Further, the company's follow-on product, the four-place DA40 Star, may have actually siphoned some sales, since both airplanes are commonly used in the trainer role.

New, Slick

When the DA20 showed up as a European import in 1994, there was no mistaking its roots as a sailplane design. It was a T-tailed, all-composite two-seater with high-aspect ratio sailplane-like wings and a huge, rear- hinged bubble canopy that made for unique—and some say awkward—ingress and egress.

Also unique was the airplane's 81-HP Rotax engine, which many U.S. pilots had never seen, since the engine hadn't made major inroads, even in the experimental market.

The Rotax-powered A1 Katanas at takeoff sounded like a sport motorcycle with a stuck throttle. Chainsaw jokes abounded. The airframe was also much slicker than students used to draggy Cessnas were accustomed to. Carrying too much speed into the flare was a common problem.

Since those early days, the DA20—in its C1 version—has evolved into what some might consider a more serious contender, thanks in part to a Continental IO-240B sporting 125 HP. Today, the DA20 soldiers on, training the next crop of pilots in fleet situations and in the traditional FBO/flight school environment.

Gone is the Rotax, which on hot days made climbing to altitude a time-building experience, although you can still find A1 versions pow- ered by it. Most were shipped to Europe, where pilots don't mind the lower power and the aircraft's unique exhaust note is considered unremarkable.

On the used market, its years of service and by now well-known maintenance and pilot requirements make it a worthy contender among the two-seat, tricycle-gear competi- tion for a personal airplane. Given the low fuel burn, it has excellent cruise performance—a good 20 knots faster than competing trainers.

Model History

In the mid-1990s, when the A1 Katana arrived, the general economy was strong and GA was showing signs of a modest recovery in the wake of disastrous sales figures posted in the late 1980s. The water- shed General Aviation Revitalization Act and its 18-year statute of repose on product liability lawsuits became the law of the land in 1994, but Cessna wouldn't re-enter the piston-single market until 1997. Simply put, there were few new trainers on the market and Cessna wasn't going to provide any two-place airplanes until the Skycatcher LSA came along more than a decade later.

The company that eventually became Diamond Aircraft had been building composite aircraft for quite some time before the DA20. Austria's Hoffman Flugzeughbau was formed in 1981 and began producing the H36 Dimona motorglider, which has evolved into the HK36 and HK36R Super Dimona, better known in North America as the Katana Extreme motorglider. Diamond says it's now the best selling motorglider in Europe and they've sold some in the U.S., too.

With that motorglider as a base, the company's management bought the fledgling airframer and renamed it HOAC-Austria Flugzeugwerk in 1989. Two years later, HOAC was acquired by Diamond's current owners, the Dries family, which is well-established in the automotive business in Europe. Christian Dries, the company's hardcharging CEO and a lifelong pilot, was determined to make a mark in general aviation— and did just that.

The new owners soon began developing the Katana DV20 by shortening the HK36's wings, as well as adding flaps and tricycle landing gear. This design evolved into the DA20 Katana, but it started life at Diamond's factory in Wiener-Neustadt, Austria, as the DV20.

The company set up shop in 1992 in London, Ontario, as Diamond Aircraft Industries. The intent was to develop a North American version of the Katana. The next year, DV20 production went into full swing in Austria. In late 1994 and based on its European paperwork, Diamond received full FAA certification of the DA20-A1, and U.S. deliveries began.

Basic Design, Safety

Even with its slightly bulbous nose, one way to describe the first Katana is "Eurosleek." Diamond has improved and tweaked the basic DA20 over the years, but it seems the Katana was mostly right fresh out of the box.

The composite design includes a pair of fuselage halves joined longitudinally down the airframe's center. The wings are similar in construction, with upper and lower halves joined in a lay-up and vacuum-bagging process. These methods yield accurate, consistent airframe parts. After assembly, the parts are hot-cured in ovens. Although this type of construction had been business as usual in Europe for years, it was new to North America. Eventually, Cirrus, Lancair and even Cessna followed Diamond's lead.

The design is nothing if not robust. The wing spar carries through the fuselage in a box structure designed to accommodate the spring- steel landing gear. Both seats are essentially attached to this structure, which has proven itself over 18 years in the rough-and-tumble world of flight training.

Although the DA20 has suffered its share of accidents and incidents, only three have been fatal in the U.S., according to the NTSB. Aviation Consumer's comparative review of aircraft safety, which appeared in the January 2012 issue, found that all of Diamond's airplanes from the DA20 to the DA42 twins have exceptionally low overall accident rates and low fatal rates.

The Katana's slender wings span 35 feet, 8 inches (cut down from the 53-foot wings used on the HK36), reinforcing its motorglider roots. De- spite their looks, the wings are only 28 inches wider than the Cessna 150/152. The wingtips have a slight winglet-like upturn to help reduce drag.

The DA20 retains the T-tail used on the motorgliders and employs a conventional elevator. The horizontal stab and elevator are just a bit above the average person's eye level, so preflight isn't a hassle, although if you want a thorough peek at the tail top surfaces, you'll need either a step stool or a short ladder.

Although other T-tail airplanes got bad raps for quirky handling—probably undeserved—the DA20 did not. Its handling is basically without sin and predictable across the entire flight envelope.

Lots of Glass

One of the nicest things about the Katana is also one of the not-so-nice things about the Katana: It has a forward-opening (i.e., rear-hinged) wraparound bubble canopy. While the resulting visibility is unparalleled for a trainer—and most other aircraft, for that matter—a hot summer day can turn the cockpit into a solar cooker. In later models, Diamond addressed this with a shaded top, and that helps keep the temperatures from approaching the interior of a pizza oven on a July afternoon.

Another less-than-appealing aspect of the canopy is that it can generate massive drag if it comes open in flight. In such an event—usually resulting from failure to latch it correctly prior to takeoff or if it becomes unlatched in flight—the canopy pivots back and presents its entire surface to the relative wind. In other words, it becomes a giant, very effective air brake.

This has happened at least once and although the airplane obviously didn't handle normally, the pilot kept it well enough under control to survive an off-airport return to earth.

In later models, beginning with those made after January 1995, Diamond added a warning light to indicate when the canopy isn't latched and improved the latching mechanism for ease of use. We're still not crazy about that aft-hinged canopy, but the accident record suggests it's not the safety hazard we imagined.

The only other issue raised by the canopy is what happens to the occupants if the aircraft comes to rest upside down. In one of the only three fatal accidents in the NTSB's files, a 2004-model Katana being used for primary instruction clipped unmarked power lines during a simulated engine-out landing. The airplane came to rest inverted and caught fire. The accident report doesn't provide details on the occupants' egress, but the CFI apparently was killed outright. The student succumbed to "serious thermal injuries" almost four months later. Worth noting is that as far as we know, this is the only incidence of a Diamond aircraft of any model suffering a post-crash fire.

Powerplants

North America's original DA20-A1 Katana is powered by a Rotax 912-F3. As such, it became the first "mainstream" Rotax-powered GA aircraft most pilots and mechanics encountered. Rotax was and is a well-known and respected maker of quality engines for the ultralight, LSA and light homebuilt market. But at the time, a Rotax was unheard of in a certified airplane.

Initially, the Rotax 912 engine had a 1000-hour/10-year TBO. In March 1999, this was extended to 1200 hours/10 years. Again in April 2003, TBO was extended, this time to 1500 hours/12 years. These values are generic, however; review a specific engine's serial number and maintenance/parts history to determine the manufacturer's recommendation. Presently, the Aircraft Bluebook Digest shows the DA20-A1's engine to have a 1200-hour TBO; the overhaul's average cost is $10,000 installed.

The Rotax engines in the A1 Katanas have delivered generally good service, although Diamond complained about overheating, which Rotax attributed to the installation, not the engine. Over time, complaints about anemic climb made their way back to the factory. For these and perhaps other reasons, Diamond switched to the Continental IO-240B in the 1998 model year, giving it 125 HP and the C1 Evolution designation.

First certificated in 1990, Continental's IO-240-series engines—which basically are two-thirds of the six-cylinder IO-360—generally have a good service record. Beginning in 2004, however, Continental released a handful of service bulletins and service letters designed to address what were termed an "idle stability problem on the IO-240 engine models."

Transport Canada (TC) put it more bluntly in early 2008: "There have been a number of rough running/unstable engine events and engine shutdowns occurring on Diamond Aircraft (DA) model DA20-C1 powered by the Teledyne Continental Motors (TCM) IO-240-B series engine."

A TC-issued service difficulty advisory noted, "Uncommanded engine shutdowns have occurred during various phases of training flights (stalls, spins and sideslips). Engine idle instability and sputtering at low power have also occurred during the critical approach phase and after landing."

To address the problem, Diamond issued a mandatory service bulletin (MSB) and Transport Canada Civil Aviation issued AD CF-2007-27R1, mandating Diamond's MSB and specifying incorporation of Revision 23 to the DA20-C1 Aircraft Flight Manual.

We couldn't find any U.S. airworthiness directives targeting Continental's IO-240 series engines. For that matter, we couldn't find any significant ADs against the DA20-C1 at all, other than some shotgun ADs related to placards or third-part avionics.

Finally, potential buyers may come across a "Katana 100" variant. This is a DA20-A1 that has been through a factory program costing some $30,000 and consisting of a complete mechanical and cosmetic refit. Part of the bargain was a factory-new 100-HP Rotax 912S and a gross weight increase, to 1654 pounds, providing a 44-pound useful load boost. This variation also is listed in the FAA type certificate and references Diamond Aircraft Drawing No. 20-0100-00-00. The Aircraft Bluebook Digest doesn't list any Katana 100 models.

It does list, beginning in 2001, an additional C1 model called the Eclipse. This wasn't really a different model but simply an upscale equipment package that included leather seats, Garmin avionics and other goodies. It remained in the model line until 2008.

Systems

In a nod to maintainability and its intended use as a trainer, Diamond made the Katana about as simple as certificated airplanes get. For example, there's no nosewheel steering. Instead, there's a castering nosewheel and steering is accomplished via differential braking, which seems to be the trend in modern fixed-gear aircraft. Early Katanas had high brake-pedal pressure. Meanwhile, a shelf-like structure built into the airframe near the rudder pedals made it difficult for those with larger feet to steer and brake the airplane. This was corrected in later models.

Except for the rudder, which is cable-operated, the flight controls are activated via push rods, which generally provide the pilot with more feedback and responsiveness. The flaps are electric with three positions: retracted, takeoff and landing. The flap switch is panel-mounted and includes a position indicator.

Pitch trim is electric, with no manual provision, yielding one of the few things we don't like about the airplane. A rocker switch on the center console behind the throttle operates an anti-servo tab on the elevator (A1 models), but fine-tuning the trim can be an exercise in excess.

We think the Katana's center stick is one of the airplane's strongest assets. We've always believed students or pilots new to a type adapt more quickly to a center stick, which we prefer over yokes and the more recent innovation of side sticks. Even pilots who don't like the Katana for other reasons seem to like the stick.

The Katana's fuel system, while as simple as the rest of the airplane, does pose a potential problem. A single aluminum tank is located behind the seats, forming the baggage compartment's floor. It holds 19.5 usable U.S. gallons in the Rotax-powered A1 version and 24 U.S. gallons usable in the C1. In both models, it's filled from a cap located on the fuselage aft of the pilot's seat.

As a design feature, we don't like the idea of putting fuel lines and hoses in the cockpit space, let alone the entire tank. In our view, the gasoline should be outside the people area, preferably in the wings. Even so, we're aware of only the previously mentioned single accident involving post-crash fires

Since there's only one tank, switching isn't an issue. The single shutoff valve is located on the left side of the center console, near the pilot's feet. The tank has one sump drain located on the left side of the fuselage. In Continental-powered

C1 DA20s, an additional fuel system drain is installed on the fuel filter bowl. All DA20s are 12-volt air- planes. The airplane is all-electric, but DA20s usually don't have extensive avionics for the simple reason they were never certified for IFR operation, something many flight schools and owners have complained about.

A1/C1 Differences

The Rotax-powered Katana A1 is an easy-to-fly starter trainer, but many flight schools wanted more. The main thing they complained about was poor climb performance. Diamond's first solution to the performance problem was the aforementioned Katana 100 retrofit program.

The second solution involved the C1's Continental IO-240B, with 125 HP. At the same time, Diamond tweaked up the basic airframe, squeezing an impressive 60 pounds out of it. This helped accommodate the heavier Continental engine.

With the lighter airframe, the C1 also got a redesigned horizontal stabilizer, eliminating the anti-servo tab. It also got slotted flaps in place of the A1's hinged flaps and the canopy latch was improved, as were the brake master cylinders. Wing sweep was tweaked by half a degree.

Ergonomically, the instrument panel was moved higher and further forward, creating more knee room. Seatback recline angle was increased to improve comfort. This was a necessity, in our view, because although the fixed seats—the rudder pedal position is adjustable in all models—are comfortable enough for a short training session, they can be excruciating on a long cross-country. Even so, some owners complain that the seats are rock-hard after a flight of more than an hour.

There were some name changes, too. The C1 initially carried the Katana name but in 2000, Diamond renamed the airplane the Eclipse and Evolution, with the former being the gussied-up airplane intended for private owners and the Evolution the training model. The Eclipse has rear windows, pop-out vents, wheel pants, inertial-reel harnesses and Garmin avionics versus Bendix/King products in the Evolution.

Performance, Handling

Stick-force-to-G is a bit on the light side, which is fine for a trainer, in our view. While we don't think manhandling will ever pull the wings off a Katana, students should find it light enough to be easily mastered. The ailerons are effective—and what adverse yaw there is encourages rudder use. But rudder input requirements remain light-pressure-on-the- pedal, not the thigh-numbing stomp encountered in heavier airplanes.

Stalls are quite gentle and even when we've tried to provoke the airplane into something more sinister, it won't go along. Although plenty of students have ham-handed Katanas and broken plastic as a result, none of these have been due to stalls or stall/spins, as far as we can tell from reviewing the Katana's accident record. The airplane is approved for spins, with the flaps up, something desirable in a trainer.

In addition to its training duties, the Katana is perfect for low-and-slow cruises across the countryside. The Rotax-powered Katanas cruise in the 110- to 115-knot range, which makes them a bit faster than a Cessna 150. Expect fuel burns of 3.5 to 5 GPH, which places the A1 Katana firmly on the positively frugal end of the spectrum

The Continental-powered C1 version burns more fuel, but is quite a bit faster. On 7.3 to 8.3 GPH, it'll true out at 125 knots. Also, the C1 comes with a noticeably improved climb rate, easily turning in an 800 FPM initial performance, bleeding off to 500 FPM or so at practice-area altitudes. If you don't think that's a considerable improvement, you haven't spent much time instructing.

As should be expected when considering its role, Katanas have adequate but not generous payloads. Early A1s had empty weights of about 1160 pounds against a gross weight of 1609 pounds. That yields a useful load of about 450 pounds. Throw in full fuel and there's barely enough payload left for two FAA 170-pounders. Obviously, a pair of 200-pounders up front won't cut it.

Allowable baggage weight is 44 pounds, which is quite generous considering that there's very little space behind the seat for anything more than underwear and a tooth- brush. The Continental versions have a higher gross weight of 1764 pounds for a typical useful load of 600 pounds. That means full fuel and a pair of heavier pilots up front is a realistic option.

Maintenance, User Groups

Given its simple airframe and overall design, Diamond predicted the DA20 would be a low-maintenance airplane. That's true, but the airplane isn't without foibles. Thankfully, none of them are deal breakers, in our view.

Brake wear and replacement rates can be high, which should not be a surprise, since the airplane is steered with brakes. Early in the A1 version's history, there were a number of reports of cracked spinners. One reporter found all nine of his fleet aircraft with cracked spinners, suggesting pilots pushed on the spinner during ground maneuvering.

A recent review of the FAA's service difficulty reports did not uncover a series of related or linked problems. In the Rotax models, we saw complaints about oil pressure issues and broken exhaust springs, but few beefs about the airframe itself. We didn't find many repeated complaints about the C1, either. There were the usual reports of cracked parts—nosewheel assemblies, rudder pedals, some composite components, but nothing we would consider a characteristic flaw in the airplane. This tends to indicate to us the type has matured and installing revised components—either in the field or at the factory—has resolved many recurring issues.

The DA20 can be thought of as being relatively AD-free. We count eight ADs, on the A1 version and only one on the C1 version. All of these ADs are of relatively minor consequence, not the gotcha variety that might queer a pre-buy inspection.

The Diamond Aviators Association (www.diamondaviator.org), was formed in 2007. A traditional type club, the organization has more of a virtual presence than a physical one, but acquired the apparently defunct Diamond Owners and Pilots Association and merged its membership. The organization says it is independent from but endorsed by the manufacturer and works closely with Diamond to maintain a two-way flow of information.

Reader Comments

I own and operate Summit Aviation, a busy flight school in Bozeman, Montana. We currently operate five DA20 aircraft, as well as DA40s, DA42s, a Cessna 182RG, a Cessna 172S and other aircraft. The flight school began with one Cessna 150 in 2000 and grew to a fleet of Cessnas in 2004.

In 2005, the flight school was growing exponentially, requiring us to consider a fleet of aircraft. My plan for a new Cessna fleet was reconsidered after a friend convinced me to fly a Diamond before moving forward. I flew a DA20 and was immediately sold on its safe flight characteristics, economy, modern design and fun factor.

Fun to fly is very important to me as a flight school owner. After many thousands of hours in training aircraft, it's easy to lose the thrill of flight. Our beautiful mountainous environment combined with the incredible visibility and fun flight characteristics of the DA20 has been a major key to our success. Student and CFI retention is well above average with our school.

The first DA20 was a tough sell to the students initially because it just didn't look like other aircraft. After a couple flights with a few willing students, it wasn't long before the bulk of our fleet was converted to Diamonds. The DA20 proved to perform better at our high elevation airport than other aircraft in our fleet. We could climb and cruise faster and at half the fuel burn.

We found that the DA20 nearly cut our fuel, maintenance and insurance in half from what we were seeing with the 172s.

The ability to offer a brand-new aircraft for the same rental price as the competitors' 30-year-old trainers gave us the leg up needed to succeed. We were also able to get through difficult economic times and high fuel prices, due to the fact our aircraft were so inexpensive to operate.

After more than seven years of operating Diamond aircraft, we have experienced an incredible safety record. The low stall speed, docile flight characteristics and strength of the airframe have contributed to our safety. Every pilot makes mistakes.

It helps me sleep at night knowing my students are flying the most statistically safe training aircraft available. Success as a flight school is due to many factors. Our amazing staff, good business practices, effective advertising, safety programs and a focused effort have helped us succeed. I do believe, however, that if I did not take my friend's advice to fly the DA20, our school would not be the success it is today.

Ben Walton, Summit Aviation, Inc

I fly a 1996 DA20-A1 (with the Rotax 81-HP engine). It is a joy to fly, with excellent visibility, smooth/responsive controls and an excellent safety record. I cruise at between 95 and 122 knots, depending on how much fuel I want to burn en route, and see an average of 3.7 GPH over the past year of operation.

My insurance is about $900 per year and while parts are expensive, Diamond has done an excellent job supporting us, providing a new downloadable (free) illustrated parts catalog. Annuals have been between $650 and $980 a year. My mechanic lets me assist to keep costs down.

Everybody thinks it's an LSA. I think the DA20 is the earliest all- composite aircraft still in production (Windaker Eagle #1 and Beech Starship #2). A1s rarely come up for sale and when they do, they don't last long. Unfortunately, most get boxed up and exported to Europe where avgas is $12 a gallon or more. Of the 341 made, the FAA registration database lists fewer than 50 still flying in the U.S.

I only wish there were more still here so owners could meet up, exchange experiences and help keep them flying. An excellent online resource is Diamond Aviator's Network forums at www.diamondaviators.net.

Alex Gibbs, Via e-mail

I got my pilot license flying a DA20, rented DA20s and when tired of renting, bought a used DA20 from the flight school. In the last five-plus years of ownership, I have enjoyed taking care of my DA20.

Adding wheel pants and an MT prop, I now can get 140 knots TAS, still on 6 GPH. When first insured, the cost was close to $2000. Now it is just over $800 for the year. The annual at the Diamond service center at my airport is very thorough, but very expensive. Maintenance between annuals is light. There have been some repairs along the way, but nothing what I would consider odd.

Name withheld

This article originally appeared in the September 2012 issue of Aviation Consumer