lenthamen,
out of curiousity what’s the climb rate up there in a DA40? And what’s the TAS?
The climb rate will be around 700ft up to FL100. At FL100 you’ll still have 100% power available thanks to the turbo.
When getting higher, the available power will decrease and so will your climb rate.
The climb rate will be about 400fpm at FL150.
I do about 145kts TAS at FL150 with a fuel flow of 6.1USG.
This is with the Centurion 2.0s engine which has far better performance than the original 1.7 Thielert.
FL200. DA42. Was still climbing nicely, but only me on board..
17,650’ in a PA-28 160, 26th January 1971, Oxford, Kidlington (CPL course record).
The final 500’ took 35 mins, 2 notches of flap, hovering on a stall. Very near encounter with a southbound Viscount.
FL300 in a Piper Meridian…
FL150 in a C182
FL110 heading from Vilshofen to Pula….
Interesting question… I fly a lot at 8000 ft or so, and occasionally over 10,000 ft to clear airspace, but in a power plane I’ve never felt any motivation to fly into oxygen levels. I did fly to 10,000 ft with 65 horsepower on trips a couple of times 
I don’t often have any reason to go that high, if terrain or weather is over 8,000 ft I generally go around it. Weather is not often an issue.
With others as PIC I’ve flown to 18,000 ft in a glider (purely because we could, for fun) and 44,000 ft in a jet (to get over a storm)
17,650’ in a PA-28 160, 26th January 1971, Oxford, Kidlington (CPL course record)
Well done. Without oxygen?
FL248 with engine not running in a winter mountain wave over the Black Forest, Germany.
FL100 – for lack of oxygen. I know of course that I can go up to FL130 for 30 minutes, but so far I haven’t been in a situation where there would be any point in doing so.
But any day now, I’m going to take an aircraft up there just to have done it.
