The DA-62 has become the benchmark to beat in light piston twins.

The future is here

Text and detail images by by Guy Leitch

The star at this year’s Aero Expo South Africa, held at Wonderboom, was the Diamond DA-62. The demo aircraft was flown out to South Africa especially for the event – showing the easy capability of this latest generation piston twin.

Cars have advanced technologically and in comfort and performance enormously over the past 60 years. Light aircraft are however still stuck in a time warp – with the mainstream piston twins being the geriatric 50 plus year old Beechcraft Baron and Piper Seneca. Aircraft should be cutting edge technology, yet it is cars that have evolved, not planes.

The objective was to build a state-of-the-art piston twin equivalent to a 7-seat SUV.

The DA-62 displayed at Aero SA 2023 was my second opportunity to experience this remarkable plane – which has rewritten the performance, safety and comfort standards of piston twins – and, dare I say, rendered the two American offerings painfully obsolete. And each time I check it out I am more impressed than ever.

The Big Idea

Finally there is a genuinely modern new piston aircraft – and it shows the American manufacturers litigation induced inability to create new products in a poor light. Even the normally pro-USA and conservative Flying magazine reckoned that the DA-62 belongs on “the shortlist of the greatest light twins ever. In a word, it’s a winner.”

You have to fly the Diamond to appreciate it. It just does everything better, especially when compared to twins such as the Baron 58 and Seneca 5 with which it directly competes.

A King Air salesman once said to me that anything man made will eventually fail. And piston engines are definitely fallible. So there will always be a market for light twins – if only they were better than the aforementioned Baron and ‘Sneaker’.

If cars could have advanced why not GA planes? Diamond Aircraft founder and CEO Christian Dries reportedly challenged his team to create a simple-to-operate, fuel-efficient twin and wrap it around a passenger compartment that was on par with the latest luxury sport utility vehicles (SUVs).

Like a Range Rover, it needed to be fast and comfortable. And like a big SUV the DA-62 has a remarkable official seven seats, although it’s really a 5 plus 2. But with its third-row seats, oversize doors and seats that fold flat to accommodate bulky items, the DA-62 is a genuine SUV, like a Range Rover with wings.

Unlike fuel-guzzling SUVs, the DA-62 manages the hitherto mutually exclusive achievements of having both excellent speed and fuel economy. You may argue that if you can afford a new DA-62 then you don’t need to care much about fuel consumption. But long term its important – especially with Avgas above R30/ litre, if you don’t want every hour of flying to have burned a large hole in your pocket.

At max continuous power the DA-62’s twin 180 hp Austro AE330 diesel engines burn less than 10 gallons of much cheaper JetA per hour per side, giving a top speed of around 200 knots. Pull the throttles back to 75 percent power and the speed is still a respectable 187 knots, but fuel burn drops to just 7.4 gph per side — an impressive 14.8 gph. That’s 12.5 nm/ USG and easily beats my standard measure of reasonable fuel consumption of 10 nm per USG which our C182 struggled to achieve with just one engine at a tedious 125 knots, or similarly, our turbo Saratoga II at 17 gph for 165 knots.  In contrast, a Baron 58 burns 28 USG for 175 knots which is just 6.5 nm/g – or more than twice the fuel consumption.

In ZA Rands, with Avgas at around R33 / litre, the Baron will be burning about R3,700 Avgas an hour compared to the DA-62’s R1440 per hour, almost a third of the Baron’s cost! And the big thing is – the DA-62 burns JetA, which typically costs just two thirds the price of Avgas – and is available almost everywhere.

If it wasn’t for legacy engines, all planes should burn JetA, as Avgas is becoming increasingly scarce and erratic in its supplies. If you feel uncomfortable trusting your life to a single piston engine over cloud, unlandable bush or water, or at night, and you want the power and systems redundancy that come with a second engine, the DA-62 is a no-brainer.

On the ground

The DA-62’s functional but gangly looks are a talking point. Some say it looks great, others say it looks fugly. But there can be no doubt that the quality of the cabin is right up there with the best automotive finishes. It’s clearly not a Cessna or Piper. The leather is hand stitched, the seats supportive, and everything fits beautifully. And even better – there are doors on both sides of the cockpit so you don’t have to rely on you passenger to close the door properly.

The doors are gull wings but it is easy to step over the sill and slide one foot over the stick and then get your backside on the seat and finally hoik your other leg over the sill and into the footwell, but you have to be supple. A notable feature is that the seats are not adjustable, instead you can electrically adjust the rudder pedals.

The DA-62 wing has a noticeably high aspect ratio and thus long wingspan. At almost 15m they are too long for a standard T-hangar. The wings and nacelles hold a 189L main tank and a 137L auxiliary fuel tank.

Despite having engines protruding forward either side into your field of vision, the view out is better than many twins – especially the Seneca.

The engines are controlled by an electronic engine control unit (EECU). These modern diesels deliver far better fuel consumption than conventional gasoline engines, and significantly reduce CO₂ emissions.

Like modern equipment should be, but seldom is, the DA-62 is simple and easy to operate. A noteworthy optional pilot interface is the neat Garmin GCU 476 keypad in the centre armrest. This takes out the horrible hand wobble and then finger stab to select a function on touch screens.

There is no longer a colourful bouquet of six power control levers for the two engines because there are no prop pitch or mixture levers. 

The engine start is like a jet; just flick the aircraft and engine Master switches on, wait a few seconds for the glow plugs and then push the engine start buttons. The Austro diesels whirr smoothly into life as the dual-channel FADEC manages the rpm and checks for faults.

The before takeoff vital actions and run-up is equally painless. Engine run-up is simple. Set the park brake, manually select A and then B channels of the electronic engine control units (EECU) to ensure both are online, and then just push and hold the engine run-up buttons. The AE330’s FADEC automatically increases power to 1,950 rpm and performs a number of health checks, including cycling the props.

If no fault messages appear on the Garmin G1000 when the test sequence is completed, you’re ready for departure.

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In the Air

Taxying out from Lanseria’s South side, with Diamond demo pilot Markus Fischer in the right seat, we used the Runway 07 B3 intersection. I applied power and we were soon at 80 knots rotation. Acceleration to 95 knots for the climb-out was brisk and the nose was so high that I lowered it to see better and we still went up at 1500 fpm at 110 knots indicated. The cabin was noticeably quieter than any American spam can competitor.

Climbing to 10,000 feet at 110 KIAS, the DA-62 maintained a 1,500 fpm rate of climb with two on board and half fuel. Accelerating to a cruise climb speed of 130 KIAS produced a 1,200 fpm rate through 8,000 feet.

For a seven-seater twin with just 360 hp, the DA-62 claims an impressive 200 knot top speed. I wanted to see it for myself. With the throttles full forward to maximum continuous power of 95 percent, I let the speed build. It was an ISA plus 15 day and we were below the engine and wings’ optimal 14,000 ft altitude, but on the G1000 I still saw 187 knots one way and 202 back the other way for an average of 194 kts.  And this while burning just 18.6 gph. Doing a similar speed in a Baron 58 would burn around 34 gph, so I could not help but be impressed.

Although the factory says 95% continuous power is fine, I thought a less stressful 65% would be more likely. In real life this gave 172 knots at just 12.5 gph.

I had not flown a light piston twin for many years, so once were at 10,000 ft I asked Markus to handle the demonstration of the DA-62’s single-engine performance. Initially he just throttled it back to the zero thrust setting but with a bit of encouragement I got him to switch off the left engine (the critical one) Master switch. The propeller immediately stopped, yet without the jerks of geared engines such as a Rotax, and automatically feathered. There was no need for the frantic litany of “Identify Verify Rectify” – to make sure you feather the correct engine.

No matter how modern or sophisticated the design, the physics of a piston twin on one engine are inescapable – the plane yawed left and I instinctively applied right aileron to ‘raise the dead’, pushed in a dose of right rudder, and then just trimmed it out. After that, the DA-62 was as easy to fly on one engine as on two. The autopilot is the Garmin GFC 700 which includes a yaw damper and this makes a huge contribution to convenience and reducing pilot workload and situational awareness, and thus improving safety.

For a few years I had a share in a Baron 55. My wife loved it, but I stopped flying it when I recognised I needed an unaffordable five hours a month of proper single engine work just to stay current. In contrast, the autofeather and simple systems makes the DA-62 easy and safe to fly – even for the infrequent private pilot.

Earning a multiengine rating in a DA-62 with its two power levers would be too easy, kind of like doing it on the Cessna 337 ‘push-pull’ which provided a twin rating restricted to centre-line thrust.

The DA-62s all-important Vmca (velocity of minimum control in the air) – (ie the speed at which you run out of rudder) is 85 KIAS, with an 87-knot blue line (single-engine best rate-of-climb airspeed) giving a slim margin. Trimmed at 90 KIAS the handling was still sweet and we were climbing at a healthy 300 fpm.

Markus pointed out that if you really want to save fuel you can shut down the right engine and do 100 knots at just 3.6 gph. I did a quick mental calculation and realised that, even with less than half fuel on board, at that fuel burn, our flight endurance would be more than 11 hours. I wonder if they will supply a DA-62 with a potty?

The numbers for this plane are really impressive. It will haul a payload of over 1,000 pounds for 1,300 nautical miles with a full-fuel. Its engines sip Jet-A while offering the peace of mind that comes with a 13,000-foot single-engine service ceiling (at max gross weight) and the turbocharged power to propel it to respectable top speed.

We headed back to Lanseria where Markus was happy to let me do the landing – which was a complete non-event with speeds pretty much the same as the Saratoga. The big sturdy trailing link landing gear will flatter hammy pilots, but unlike say a twin Comanche, the DA-62 wing does not suddenly stop flying.

After shutdown I considered the value proposition. I wish I could afford one, but at about US$1.5 m it was way out of my humble price league. Nonetheless it’s cheaper than a Baron G58, which comparably equipped would not give you much useful change out of US2m.

I reckon I’ll have to buy a lottery ticket.