Erratum
There was a heated debate on the Diamond forum.
Actual flight data shows that in the real world, it is impossible to use full sea level manifold pressure due to excessive CHT.
As a result, the performance gain is only present above 6-7 K feet – one owner has even reported a performance penalty at very low altitudes.
I have previously (mis)understood and propagated that one could use 30 inches all the way to 7000 ft. This is just not supported by the actual logs.
Below FL090 the actual cruise speed data is also not much different from what I used to see routinely with the PowerFlow equipped DA40XLS.
The supercharged planes apparently only really shine above FL100…
No free lunch I guess. Apologies…
Good video – thank you for posting it.
Yes; conductive paints are widely used in electronics for EMC (electro magnetic compatibility/compliance) reasons. Carbon paint (as used by Diamond) is the cheapest form, it has quite a high conductivity but is fine for static dissipation. It gives little protection from radiated EM and – as with all paints – none at all from magnetic fields. Above that you get stuff like zinc which costs more but is more conductive and usable for shielding electronics which radiates, or which needs to be shielded from radiation. Above that you get silver which is very expensive but almost as conductive as a solid layer of metal. And some others in between.
Some other certified plastic plane makers use a layer of metal mesh which is laminated in as one of the layers. This is much better than conductive paint because if you get a wide piece of it, it will conduct a lightning strike, which carbon paint won’t.
How Diamond demonstrate lightning protection I don’t know, but they must have done it for certification.
Diamond have some nice equipment and procedures. in avionics terms, they are probably at a similar level (or slightly above) what Socata were doing. Other piston manufacturers have been hand building everything.
Not DA40 specific, but very cool video from AVweb on the Diamond factory.
Had no idea they use a conducting paint to dissipate static electricity.
https://www.avweb.com/multimedia/votw/how-diamond-builds-composite-airplanes/
(Or if they rearrange their site again, the direct youtube link
Look at the DA40NG’s POH numbers and fatal accident rate and go fly both planes side by side.
Is the NG more fatal?
tmo wrote:
Why not just look at the CHTs since there is no turbine to burn with excessive EGT/TIT?
Looking at the CHTs is a very good idea because inlet air is hotter than in a normally aspirated DA40, so it is especially wise to avoid higher CHTs which reduce detonation margin.
Watching the EGT (and making sure that one is far enough away from peak EGT either LOP or ROP) also helps.
europaxs wrote:
Flyingfish wrote:
I think this further increases the attractiveness of the Lycoming powered version (my favorite) for highlanders.
It’s unclear to me, why one would add a supercharger to a second-hand Lyco-version, making it even more expensive with the additional need to watch MP at lower altitudes and sucking so much more (leaded) fuel compared to the Austro-powered 168 hp Turbo-Diesel DA 40. The latter is much more economical, quieter, smoother and even much simpler to operate with the single lever. All that without the toxic lead.
I hope I am not starting a religion war…
there is no question the Austro is a modern, very smooth running and economical engine. It has one killer problem from my perspective: weight.
Look at the DA40NG’s POH numbers and fatal accident rate and go fly both planes side by side.
The supercharger costs zero weight penalty and therefore preserves the wonderfully balanced “original” DA40 flying characteristics.
This said,I totally agree that the additional workload of watching MP and keeping it below the limit is a big nuisance.
I also believe that one should carefully watch inlet air temperature especially on hot days and lean accordingly.
But the performance boost is so big that it still makes sense to me… with the Alps being my home turf…
Flyingfish wrote:
I think this further increases the attractiveness of the Lycoming powered version (my favorite) for highlanders.
It’s unclear to me, why one would add a supercharger to a second-hand Lyco-version, making it even more expensive with the additional need to watch MP at lower altitudes and sucking so much more (leaded) fuel compared to the Austro-powered 168 hp Turbo-Diesel DA 40. The latter is much more economical, quieter, smoother and even much simpler to operate with the single lever. All that without the toxic lead.
30k AMUs for 6" of boost is crazy expensive.
Hmmm I bet a lot of Ferrari owners would pay 30k for extra 6" 
I don’t think the supercharger is always on on all aircraft. If I remember right, the LET L-200 Morava has levers to manually engage the superchargers.
On the DC-3 I think the superchargers are always on but has two gears (low blower/high blower) that the pilot can change between.
With the supercharger always on, and not having some kind of MP limiter (like the wastegate on a turbocharger) would probably make the aircraft unsuitable for club use, just as if it had a turbocharger without wastegate (Turbo Arrow, very nervous turbo in my experience).
“Why not just look at the CHTs since there is no turbine to burn with excessive EGT/TIT?”
Yes, that is a good question.
>30k AMUs for 6" of boost is crazy expensive.
