Hello All,
Since I am not an owner yet (I should purchase a DA20-C1 in April if all goes well), I am posting here my reply to the DA41 thread in the DA40 forum here. I hope you enjoy it. Please take the following with a grin of salt, I let my imagination go wild.
A better DA40
First, a disclaimer. I have a total of one flight in a DA40, so I am by no means an expert in that model. I have experience with DA20-C1s, 172s and 150s. And I fly on occasion as copilot in my friend’s 182. The DA40 is in my humble opinion already a great aircraft, so the idea of making it even better sparked my interest.
I drive a stick shift car. I love to make one with the machine. I dislike automatic transmissions, and I am a lousy passenger, so I can’t imagine being in a self-driving car one day. The same goes for airplanes. I once made a long flight with my friend in his 182. We took off, then the gps and auto pilot took control up until we entered the circuit at our destination a couple of hours later. Our job was to basically scan the gauges and the sky for traffic and manage communications with ATC. Not my idea of fun, but my friend enjoyed this automation very much. Now I do appreciate the autopilot in IR, as it significantly reduces the pilot’s workload.
Everyone’s got their pet peeves and preferences when it comes to aircraft. Myself, I prefer the quick ailerons and center stick of the DA20/DA40 with pushrods for controls over the pulley and cable systems of the Cessnas and the side sticks of the Cirrus. I wish the DA40’s ailerons were a little faster though. In that sense, the DA40 feels more like a truck than a DA20, just like a 182 feels like a heavy truck compared to a 172.
I am only 175cm tall, 5’9”. The DA40 and C182 have taller panels than the DA20. I would love the forward view to be improved by designing a smaller panel in the DA41.
I have been designing, building and flying several radio-controlled aircraft in the past. I am convinced several concepts translate directly to plane design, so I will provide my ideas here.
First of all, like others have said, I would put the airframe on a diet, with the stated goal of lightening it by 250 lbs. This would increase the useful load, which is a complaint we sometimes hear about the DA40.
I would also try to locate a lighter, smaller, all aluminum engine with a turbo compressor. Heck, my 2013 Jetta GLI has one, why would it be impossible to get smaller, lighter, more fuel efficient power plants sporting small, reliable turbos in airplanes?
Secondly, I would use the DA50’s fuselage, as it is roomier than the DA40. I would try to have as many common parts with the other current Diamond aircrafts as possible, so as to reduce the costs (design, certification, but also inventory)
I would keep a 180 hp engine, maybe go up to 200 hp, but no more than 4 cylinders. That should be more than enough power in my opinion. A bigger engine weights more, requires more fuel, introduces heat dissipation problems, and costs more to purchase and to operate.
A new propeller with a different airfoil might add to the cruise speed, at the expense of climb rate.
I would shorten the wings by 12-18 inches. This would 1) increase cruise speed (highly desirable), 2) make ailerons livelier (highly desirable in my book), 3) make the aiplane fit in tighter parking spaces, and 4) increase stall speed by 5-7 knots, which is undesirable, but as with other things in life, everything is a trade off.
I believe the combination of optimized aerodynamics, weight reduction and a shorter wing could potentially generate an extra 15-20 knots of cruise speed, with no increase in fuel consumption while providing a roomier cabin. We would have been able to gain even more speed had the current design been not already very efficient aerodynamically.
I would make ailerons more effective by slightly shortening the wings, increase ground clearance by a few inches, and find a magic way to make the airplane usable on gravel strips without damaging the composite airframe or propeller (use Kryptonite maybe), and also make the airplane capable of landing on shorter and less than perfect grass strips. This would open up several hundred airfields in North America on which I would not want to land on with a DA40 for fear of damaging it.
I would also decrease the price of certified replacement parts, because that too is part of the total cost of ownership. The new Chinese ownership might be able to produce parts at a lower cost, one can only hope.
How could we make the DA41 a resounding success? First of all, better targeted marketing and promotion towards people who have the means to purchase an airplane. That includes the new rich people of China. A better website in many languages. Diamond Aviators fly ins all over the place during the summer months. Diamond aircrafts on display in the casinos in Las Vegas, in the hallways of major airports all over the world.
Pilots nowadays fly fewer hours per year. I believe a lot of effort should be invested in making life easier to rusty pilots, in the cockpit, with all sorts of electronic flying aids. The glass panels should be simplified. The current crop of glass panels have been designed by engineers and it shows. I believe their interfaces could easily be made a lot easier to use.
Examples:
Add a Start button which will, well start the engine! No more fiddling with prime pumps, mixture or power. Gets that engine started on the first try, every time, no sputtering, no drama. My car does it, why not on an airplane? While we’re at it, at that price point, add keyless entry please.
Only bluetooth headsets, no wires.
Slot for putting a sim card in the radio stack – gives you 4G mobile internet and phone number
With aforementioned Sim card ans mobile service, automatic update of all maps, approach plates, etc. Without the need for human intervention. You are always up to date.
Sirius XM radio – because you just can’t live without the Bluegrass channel and you know it
Put Foreflight features directly in the instrument panel, at prices comparable to an iPad with a Foreflight subscription.
When I submit a flight plan in ForeFlight, the airplane, which is connected to the internet via its mobile sim, gets the flight plan. I might be dreaming here, but the airplane could read the flight plan acceptance from the FAA and automatically set the transponder code accordingly.
Automatically suggest the available frequencies in the area and let the pilot select the frequency with a touch screen
Since the airplane basically runs ForeFlight, it could automatically turn on or off the transponder at appropriate times.
Automatic computer driven leaning, monitoring of fuel and oil pressure and temperature, cylinder heads, rpm with audible alarms when things become yellow, then red.
The experimental side of aviation has produced incredible innovation over the last few years. It is high time that the certified market gain better avionics at a significant reduction in costs, both in acquision and installation, with a weight reduction as well.
Add a mechanism against shock cooling. Around here, some winter days are pretty cold, and we need to be careful not to shock cool the engine, especially then coming for a landing while fliying with the engine idling. Would it be so difficult to have the computer which monitors the cylinders temperature also control air intake to keep the engine within normal operating temperatures?
If you have written up until here, congratulations, I will offer you a beer next time you come to visit Montreal, QC.