Black Diamonds Aero

[Antoine]

Bret let us discuss the details of your vision and see how this fits.

I believe that the DA40 has considerable untapped potential.
it can become a much better cruiser, but we must carefully plan a step by stp approach.
And we must address certification...

Kai: dont know what Bret has in mind, as far a Im concerned, increased payload is the top priority, and increased effiiency the second. If this would result in 10 more knots, it would b perfect..

PS, just checked: with the MT Scimitar 72" prop, the prop clearance is 12" or 30 cm.

[Jean]

Hello Antoine,
MTOW increase is also my priority.
Don't you think it would be easier to use DA 40 NG's Nose and Main gear design to reach that aim?

[Kai]

Hello Antoine,
MTOW increase is also my priority.
Don't you think it would be easier to use DA 40 NG's Nose and Main gear design to reach that aim?

MTOW of the DA40NG is up to 1280 kgs. http://www.diamond-air.at/austro_engine_upgrade01.html

I am not sure if the guys from Diamond want to sell their gear and help you with the STC...

[Antoine]

I am not certain but I believe Diamond only changed the MLG to support the 1280Kg / 2820 lb MTOM.

Jean, I think it is worth looking at a new design because Diamond makes solid steel struts and adds fairings, which makes sense for a trainer. Using aluminum or composite airfoil shaped struts is probaby a lighter and more efficient solution for owner operated planes that do not need to accept many botched landings... Beyond its design load, a steel strut will be bent, whereas a CArbon Fiber part will burst apart, resulting in a severe incident at best...

But the biggest issue is in my opinion spin certification. The NG has a very heavy engine that eliminates the aft CG situation. I do not know how the DA40-180 with the new MTOM will behave in a spin.

My CG calculations indicate that making use of the full MTOM requires 20 lb of ballast (heavier prop) AND the cg will be sitting at the upper right corner of the CG envelope of ... the 40 gal planes, ie outside the legal range for a 50 gal plane.

Since we will also be redesigning the cowling, we could rework the engine mount to move it about 3-4 cm forward. That would cost some money but eliminate the cost of a mandatory prop upgrade. If we do it well and really push the cg forward, it may also allow
1) recertification of the 50gal planes for the full CG range,
2) make the winglets that Diamond took out of the XL acceptable again. And the winglets would give us the climb rate increase we need...

[Jean]

They talk about main- and nose- gear reinforcement in their link.
Looks like you are going to build a whole new plane, so why not this blower in front
http://www.diemechturbines.com/TP100.htm

[Erik]

That's a very interesting very low power turbine engine. 180kw? You could almost hang that on an experimental DA40. Has it seen any airplane applications yet?

[Antoine]

Turbines are great from the perspectives of weight-to-power and reliability.

Specific fuel consumption is around 0.65 to 0.75 lb/hp/hour.
That's 35-50% more than a piston engine.
While it is possible to achieve better efficiency in multiple stage turbines, the resulting complexity, cost and weight penalties are not compatible with the low end of the power range.

And then the other bad news: I have read somewhere that turbine engines have a time limit for overhaul - 12 years I think for a Walther.
The overhaul budget is a 6 digit USD figure. So if you're flying say 100 hours per year, you'll have to put aside maybe $ 100 per flight hour for the engine allowance alone...

No free lunch :-D

[Jean]

That's a very interesting very low power turbine engine. 180kw? You could almost hang that on an experimental DA40. Has it seen any airplane applications yet?

There's a RV10 kit in progress. Check the video on avweb
http://www.avweb.com/news/snf/SunNFun20 ... 386-1.html

Specific fuel consumption is around 0.65 to 0.75 lb/hp/hour.
That's 35-50% more than a piston engine.
While it is possible to achieve better efficiency in multiple stage turbines, the resulting complexity, cost and weight penalties are not compatible with the low end of the power range.

Even with Jet A1 the cost per hour would be too high. I guess DA 40's slow speed won't help turbine's efficiency either.

An electronic injection equipped IE-0360 or -390 Lycoming (such as Rotax 912 iS) would be a nice solution for a good power/weight/consumption ratio.

Looks like Deltahawk is progressing on the diesel front. According to Avweb's podcast, they foresee certification in 2012 (already heard that though).
http://www.avweb.com/podcast/podcast/Au ... latedStory

[Jean]

Jean, I think it is worth looking at a new design because Diamond makes solid steel struts and adds fairings, which makes sense for a trainer. Using aluminum or composite airfoil shaped struts is probaby a lighter and more efficient solution for owner operated planes that do not need to accept many botched landings... Beyond its design load, a steel strut will be bent, whereas a CArbon Fiber part will burst apart, resulting in a severe incident at best...

Antoine,
I must admit that I don't fully understand your Black Diamonds Aero's (BDS) business model.
According to Kai's link (official DAI web site), nose- and -main LG 1280 kg certified upgrade is a 16K euros option (85K - 69K ) for a TDi DA 40.
How do you plan to do better with BDS ?
What's your business plan ?

[Kai]

Antoine,
I must admit that I don't fully understand your Black Diamonds Aero's (BDS) business model.
According to Kai's link (official DAI web site), nose- and -main LG 1280 kg certified upgrade is a 16K euros option (85K - 69K ) for a TDi DA 40.
How do you plan to do better with BDS ?
What's your business plan ?

Diamond lists two options to "upgrade" a DA40 to Austros. Different MTOWs seems to be the only difference within these two. It would be interesting to find out if DAI would actually sell you the different landing gear, install it and do the paperwork for you even if you don't buy the rest of the package, means the engine. I doubt they would and if they do, they might want to apply a different pricing.

I admit it is tempting to simply ask DAI what they would charge for such an upgrade. If they do offer a reasonably priced landing gear and MTOW change, it would be a solution.