Your guesstimate: TKS for DA40

[Antoine]

That's very nice for a non-PF plane!

[Charles]

Yes, I think so too. Our cruise speed used to be about 138KTAS, very close to the AFM numbers, but it has increased gradually over the years to where it is now as we brought the plane back to almost-new state through some pretty extensive maintenance, component overhauls and upgrades, and careful surface fairing prior to repainting the wings. The PF is still an option but I've decided to hold off based on comments by mechanics about the maintenance requirements. That, and the fact that I would also need a new prop because although we have a 2-blade aluminium Hartzell, it falls in the serial number range that not incompatible with the PF.

The plane is great but icing remains a big limitation up here. In fact it was +1C this morning so we are already into icing season. TKS, even without FIKI, would make a big difference for us. I know some say that you shouldn't intentionally do anything with TKS that you wouldn't do without it, but I think this is overly conservative.

[Aart]

Interesting poll. It would certainly increase the useability of the DA40.
As to the consequences of adding it to the airframe:
1. Some loss of luggage space, assuming the only way to put the tank would be in the bag compartment
2. Weight of an empty system approx. 17 kg. TKS fluid about 1.1 kg/liter so 10 liters=11 kg and 30 liters=33 kg. Full tank in a DA42 is about 30 liters. Now, most of this weight would be added to the bag compartment, so Mass & Balance becomes a little complicated?

[Antoine]

Aart I was thinking the tank would fit in the "towbar" compartment. Would also only have about 15 liters or so since it is only meant for inadvertent ice protection. Total weight 17+16.5 = 33.5 Kg or 74 lb. Not nice, but no free lunch...

[Colin]

Casting my mind back to my DA40 days, I would have done $40k in a heartbeat.

Now that I *own* one of these sugared-alcohol pumping systems... there are a LOT of if's in there before I would plunk down what will probably be $60k. Right now the factory is chasing a possible leak in one of the many o-rings that help join all the tubes. So there's a *little* leak that is caught in the area under the nose luggage space, which is set up for just that purpose. It then leaks along the belly. Creating a similar space in the DA40 seems like it would be *really* challenging, especially since the space you are discussing is near my $80k worth of avionics electronics.

It seems you could learn quite a bit from the DA62 installation and the AC installation in the DA40. The DA62 has a filler on the exterior of the aircraft, which is much more convenient. And the AC just kills the extended baggage compartment, correct? And it has got to weigh less than your pumps, tank, and fluid, right?

What are you going to do about a gauge to see how much of the stuff you have left?

Judging from the SuperCharger effort you have a LONG project on your hands. Aren't we just a couple years from having a monthly-application spray that will keep water from beading on the surface at all?

[rwtucker]

Good to hear from you Antoine. The ball park prices you have in mind seem reasonable. I'm not sure I would do it though. If I were to invest (I should never use that word in reference to aircraft or aircraft parts) that amount of money my first choices would be a carbon fiber tail and more engine HP. As nicely as it flies, the DA40 is underpowered in relation to the strength of its airframe. I would love to dump my aft CG problem and cruise at 165-70 kts with four SOB. For where I live and fly, the speed and weight would be more useful than not having to wait out temporary Wx.

[Antoine]

Casting my mind back to my DA40 days, I would have done $40k in a heartbeat.
And it has got to weigh less than your pumps, tank, and fluid, right?

What are you going to do about a gauge to see how much of the stuff you have left?

Judging from the SuperCharger effort you have a LONG project on your hands. Aren't we just a couple years from having a monthly-application spray that will keep water from beading on the surface at all?

Hi Colin

Thanks for your vote - Replies to your comments:

- I would do nothing at all. I would loan my DA40 to CAV and them to obtain the STC. This is acceptable once I have the Extra flying.
- Per the post above, it is about 75 lbs with fluid.
- I know the folks at Garmin avionics. IF they are allowed to do it (by DAI) I am pretty certain they will let us have a TKS gauge in the G1000 software. But this is really a big IF. You also have to consider considerable modifications to the panel to hold the TKS switches and indicators.
- I am quite surprised that owners of older DA40s would consider this as it would be a worth a very large chunk of aircraft value. I was expecting only G1000 planes to "want" it.
- I did not understand your comment about AC. I would expect that - in the DA40 - it is not compatible. Either AC or de-ice.
- We will need to make a note about handling leaks, thanks for the heads up.

All in all so far I am impressed by the very positive reactions overall.
It seems that my estimate of 1-2% adoption rate within the existing base is not overly optimistic. CAV have not reacted yet, but I am guessing that a few dozen installs is probably enough to fund the STC.

In order to stay focused, I am not going to reply here to the interesting comments about other goodies (lighter tailplane, etc...) but of course we all know that the dream of a "DA41" is in the minds of hundreds of Diamond customers. Maybe we should hand over 100 POs to DAI and see what happens...

[Erik]

When I had a DA40 - I asked CAV aero exactly this question - will they ever make an STC for the DA40. And they said, no, never. Their reason is that a DA40 is not a good platform since it is not a good ice platform given is relatively low power. Now I have a turbo rocket with a big TSI520 and TKS and I understand what they meant. With excess power you have the ability to exit ice very fast by climbing if that is necessary. I think that is what they meant.

That said - CAV made an STC for both FIKI and also a noFIKI version for the M20K (m20k is the first factory turbo airplane with a continental TSI360) and up airplanes as of the early 1990s. Nonetheless, you see TKS on several earlier airplanes - I have seen it in controller on a few M20J's and one M20E. What is interesting there the M20E and M20J both sport a Lycoming IO360 very similar to what is in the DA40, although tuned for 200hp - but the J is slightly heavier so the climb is similar. It ended up on those airplanes I understand by field approval. The installation details are almost identical of course to a K since except for firewall forward, the airframes are absolutely identical.

[Erik]

My guess is that CAV will never make an STC for the DA40 because they are already selling more units than they can keep up with.

Last year I lost a stall strip in flight (which is annoying but it was summer, so it was not a ground-the-airplane problem). Well it took 4 months for them to back order me a replacement for that 18'' little piece of titanium, and it was about $1800. Next time I will ask them if they have one made of 14k gold if it might be cheaper. Seriously though, they charge whatever they want because they have a captive audience/sales base and they sell more product than they can keep up with.

[DavidS]

Antoine,

You might want to look here as well: http://www.kellyaerospace.com/thermawin ... deice.html
C300/350/400 and apparently soon sr20/22?

All electric, so just need that extra alternator instead of a tank of goop.

Honestly I'd also have concerns of being underpowered in general, let alone with the extra load on the engine and weight. I don't know the feasibility of doing both an extra alternator and the supercharger.