Some have a very sensitive choke valve 
I’ve never seen a 912 that you can lean. And I bet there will be.
Assuming he knows how to lean, there should be no difference.
I assume that was a carburettored version on the 912. I wonder how the fuel injected 912is would perform.
Interesting report. local copy
He was getting 500fpm at 10k which is the same as the TB20, so obviously the ceiling was going to be way higher than the specified 12k.
To achieve 99% blood o2 he must have used a full flow mask and a very high gas flow rate Normal numbers for say the MH O2D2 are around 95%. One passenger, as a joke, reproduced 99% by heavily cheating and having constant flow with the O2D2 wide open
He got 16214ft at -8C which is ISA+9 so that’s not bad. I would have expected 17k-18k, so really close. And he says he could have gone higher; he was still doing +50fpm.
Thanks, super nice read, I am sure a 100hp Rotax engine can do a lot of stuff, especially in an RV12 !
I “tested” Rotax 80hp in a Falke up to FL120 2pob but nothing compares to the RV12 guy: 1pob, +20hp, slick RV wings, oxygen, more experience and load of gadgets I also spotted a heavy hardware playing VFR when we were up there (the KC135 north west of RAF Brize Norton)
Here is a Falke with Rotax 80hp (SF25), book ceiling engine on is FL140, height record is FL260 and it was done engine off
A fun and interesting read : flight testing the service ceiling of an RV12 (Rotax 100hp)
http://www.rbogash.com/RV-12/Service%20Ceiling/RV-12-Service-Ceiling.html
enjoy !
Coffin corner is something for very fast (near Mach 1.0) airplanes. Not really applicable to a DA40...
My highest was FL240 with my Cessna TR182. Flight controls get extremely light at that altitude, a very unusual feel to them. I was able to maintain 95-98% O2 saturation with the Mountain High O2D2 nose cannula system which I found impressive.
IMO an aircraft engine needs turbonormalization or turbocharging. Being able to climb is the most useful weather avoidance tool and with turbonormalization one can do with a smaller engine in the first place. Turbonormalization also completely removes any hot & high worries, no need to do any calculations, no uncertainty.
Turbonormalization is the better alternative in my view because it gives you a strong engine which has some external help to keep its power at altitude, not a weaker engine with artificial ventilation to make the sea level power it needs. That's my main concern about the SMA engine. It produces about 90" of manifold pressure at sea level with two large turbochargers but quickly loses its power at altitude. A gasoline engine only needs around 30" of MP to make its rated power which is much easier to keep at altitude.
How about coffins corner?
Where would that kick in for a DA40?
20k is impressive for a DA40 and shows what a turbocharger does.
I've been to 20k several times and the plane flies and handles fine, but the IAS is quite low and obviously the rate of climb is low so the aircraft becomes extremely sensitive to the slightest downdraught and even a -100fpm downward flow will prevent altitude being maintained.
Also most autopilots cannot hold vertical speed accurately enough to maintain say 100 or even 50fpm. The KFC225 for example has a bug in that it adds or subtracts (usually subtracts) 100fpm from whatever VS figure you have preset. So it is difficult to use it to climb to FL200 where the VS is under 100fpm. One would have to use the pitch-hold mode.
Also temperature has a strong effect on the ceiling. I can make FL200 easily in ISA conditions but can struggle to make FL180 in say ISA+15. And 2012 was a strange year, with ISA+10 (or more) on most flights, even though the surface temps were below average.
One advantage of being able to fly high is that if one is flying in IMC (I would not suggest anybody without radar does long enroute sections in IMC unless 100% sure of the weather) one can climb up to a level where the OAT is below -15C and that should protect you from structural icing.
