[quote="DiamondMike1"]I assume both types are similarly constructed carbon fiber and glass fiber.

Why don't both types have the same temperature limitations?[/quote]I suspect that the difference is that the DA20 was certified years before the DA40 (or Cirrus SR20/SR22), and the FAA/EASA had less experience with composite construction back then, thus making them more cautious about issues like overheating.

For a worst case, read about the even earlier history of the Beech Starship and the challenges of getting it certified by the FAA. As one of the first composite-construction aircraft to be certified, the FAA forced Beech to way over-design the composite structure, making the plane too heavy to meet its performance targets -- and ultimately uncompetitive with King Airs that the Starship was intended to replace.

I haven't seen any effects on my avionics of high temps (and I do experience them, being based in S. TX). Having said that, I only have 3 screens (KLN-94 GPS, VM-1000, and fuel gauge). The VM-1000 (an LCD) does get a bit sluggish in very cold weather until it warms up, but otherwise nothing I've experienced.

My 430 is definitely affected when it gets warm. The screen contrast starts to fade somewhere around 90 degF. The 530 screen seems impervious to any temps I've seen so far. This was true before and after they were conversed to WAAS.

I dont think even in the Sahara you would get OAT 131 degF. However a the sealed cabin, no different than a closed car, an OAT of 98 degF could easily pass 131 degF. Note, irregardless if it was a DA20 or DA40, if the temp in the cabin reached that temp without a protective/reflective cover, your avionics would be toast or rapidly going that way. Unprotected high closed cabin temps in summer, are the love of avionics shops! Five years ago in my 182, I was parked in Texas August with OAT 100 degF for only 3 hours (without reflective covers) and my 430 screen slowly went gray on the flight back. My avionics shop saved the day, but it was a very close call.

The low temperature limit on the DA40 is for the avionics, not the structure. With regard to the upper limit, I was told at the factory that the resin and curing process was different for the DA40, thus no upper limit.

Steve

Looking at the POH for the DA20, it shows a maximum structural temperature of 131degF in the limitations section and specifies looking at the structural temp indicator between the seats when outside air temperature is greater than 100 degF during preflight.

I see no similar high temperature limitations or inspections for the DA40.

The DA40 has a limitation that it must not be operated when it's temperature is less than -40degF. No such limitation for the DA20.

I assume both types are similarly constructed carbon fiber and glass fiber.

Why don't both types have the same temperature limitations?

Thanks.