Plane & Pilot
Tuesday, June 22, 2010

DA 42 In The Second Generation

The Diamond Twin Star now has its own Austro AE300 turbo diesel engines

Flying The DA42-NG
Diamond’s Rob Johnson doesn’t look like Luke Skywalker, but he’s the lucky, designated demo pilot on the DA42, and he knows the new airplane perhaps better than anyone else. A former Cathay Pacific captain on 747s, Johnson has a variety of experience in everything from military to airline to general aviation, a perfect candidate for demonstrating the talents of Diamond’s new Twin.

Rob talked me through engine start, easier than a piston process and less critical than a jet because of the FADEC system. The glow plug trick takes only a second or two, and of course, there’s no such thing as a hot start a la turbines.

Gross weight on the new NG is 4,189 pounds against a basic 3,119-pound empty weight. This is before options such as FIKI (Flight Into Known Icing), TCAS, Stormscope and air conditioning (not yet available). Still, pure payload calculates at 553 pounds. Even reduced for the inevitable options most people buy, a typical DA42-NG should score about 525 to 550 paying pounds.

That’s not a problem for a student and instructor, but it’s also a fair number for Mom, Dad and two small kids in back. Diamond is wisely pitching the new DA42 as both a power-redundant family/business transport and a multi-engine teaching machine, and the airplane would appear to have legs for either mission.

With nearly 340 hp worth of turbocharged enthusiasm, Johnson’s DA42-NG demonstrator came off the line and scored an easy 1,300 fpm pointed uphill with two up and about three-quarters fuel in the 76-gallon tanks.

Critical altitude on the turbo diesels is 14,000 feet, and if oxygen masks are your bag, you can fly at the full 92-percent setting and see 180 knots cruise, or run a full 75-percent cruise setting at 174 knots TAS in exchange for 13.6 gph total. That works out to an sfc (specific fuel consumption) of .37 lbs./hp/hr. Most piston engines score an sfc of .40 lbs./hp/hr. or higher, so the Austro turbo diesel starts right off with a seven- to eight-percent advantage.

At 60-percent power, expect more like 152 knots burning 10.3 gph. With a useable 76 gallons in the tanks at the latter setting, the NG can endure for an easy five hours plus reserve for a range of 700-750 nm. Lesser power settings can extend that to over 1,000 nm. Diamond specifically brags of an 1,180 nm range at long-range cruise.

Johnson and I launched at the conclusion of Sun ‘n Fun 2010 in Lakeland, Fla., then flew up and away to the southeast to clear traffic in the Tampa/St. Pete Class B. (Remember when they used to be called TCAs, Terminal Control Areas, a phrase that actually meant something?) With Johnson as my security blanket and 5,000 feet of altitude, I tried a Vmc demonstration right into the stall. Johnson didn’t object, so I shut down one engine, applied full power on the other and pulled the airplane up into the stall. The result was a notably undramatic roll toward the dead engine, nothing very exciting and easy to correct.

Gentle Handling
The Twin Star’s docile nature was the subject of some debate during FAA certification on the premise that the airplane was TOO easy to fly in single-engine mode, as if any twin could be too safe. The reality is that every aspect of the Twin Star’s personality flies in the safe zone. Low-end performance is excellent, configured for the pilot who would rather not have to worry about performance at the top or the bottom of the envelope. Vmc roll and dirty stall are pretty much simultaneous, so single-engine manners are as benign as it’s possible to make them.

All The Right Moves

With standard VGs, the Twin Star can be driven down final as slow as 73 knots and transition to full stop on the runway in as little as 1,300 feet. Combine that with a 1,600-foot takeoff run, and it’s apparent a well-practiced pilot can ground the Twin Star and return to the sky from airports as short as 2,000 feet.

Price is always subjective. In this case, the subjective part costs a base $679,575. As a trainer, the DA42-NG sports good economy, one of the most comfortable cabins in (or out of) the class, FADEC automation that reduces operational procedures to their simplest form and handling that should make it easy for anyone to earn their twin rating.

Your Choice Of Diamonds

There’s a variety of other Diamonds to choose from. Indeed, Diamond has become second only to Piper in producing perhaps the most diverse and varied product line.

Diamond produced the HK-36 Super Dimona powered glider starting in early 1990, but that model was rarely exported to this side of the Atlantic. The first Diamond most Americans experienced was the ’95 model DA20-A1 Katana, a T-tailed trainer powered by an 81 hp, Rotax 912F3 engine. This evolved to become the DA20-C1 Evolution, a Continental-IO-240B-powered airplane and pretty much the industry’s only dedicated trainer in the late ‘90s. The DA20-C1 Eclipse continues as the company’s basic trainer.

Diamond’s initial Skyhawk/Skylane competitor was the DA40-180 Star, a generous four-seater with the popular, 180 hp, IO-360 Lycoming driving a fixed-pitch prop out front and a left back door for loading rear-seat passengers. The DA40 also is being offered with a diesel powerplant. Diamond began experimenting with the DA50 Magnum model in 2007, a big-power (310-350 hp) five-seater intended to compete with the Cirrus SR22 and the Cessna Corvalis models head-to-head. The DA50 is still under development.

The DA42-TDI was Diamond’s first attempt at a diesel- powered twin trainer and now continues as the DA42-NG with the new Austro diesel engines. For avgas fans, there’s also a Lycoming IO-360 version.

Finally, Diamond is well along on development of the D-Jet, a single-engine, five-seat turbine specifically designed to fly in the bottom 25,000 feet of sky. The D-Jet utilizes a single Williams FJ33-4A-19 rated for 1,900 pounds of thrust. Diamond hopes to certify the D-Jet and bring it to market in 2011 or 2012.

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