Please allow me to introduce myself...

[Henry Bartle]

Hello Everyone

I am Henry Bartle from Independence air park. 7S5. I have 3 flying Speed canards and I am finishing a SQ2000. N5HN, N137DW and N67PK. I am looking for information on why there are none flying. We will be finishing the SQ by early next year. Is there a problem I should be aware of?

I also have a Lancair IV-P. N811HB

I am going to have all the cooling come down from the top and exit the rear, just like normal aircraft. Is there a better way?

Thank you and take care,

Henry

[Marc Zeitlin]

1 hour ago, Henry Bartle said:

I have 3 flying Speed canards and I am finishing a SQ2000. N5HN, N137DW and N67PK. I am looking for information on why there are none flying. We will be finishing the SQ by early next year. Is there a problem I should be aware of?

I also have a Lancair IV-P. N811HB

I am going to have all the cooling come down from the top and exit the rear, just like normal aircraft. Is there a better way?

You have apparently cornered the world market on Speed Canards - you must love the strange beasts 😀.

I assume the question of "why are there none flying" is in regard to the SQ2K. There are one or two flying in the US, but a substantial number of the ones that ever flew have crashed, at least two of them fatally. The rest have been deregistered. Most of the few that were started were never finished. There's one at Chino that may fly soon, but it has many issues that need to be addressed first due to, well, let's just say builder deviations in structure.

The main problem with the SQ2K is that it's a lousy excuse for an aircraft, IMO. Between the Lancair IV-P and the SQ2K, I have to say that you've chosen a couple of planes with fatal accident records that are far worse than the EAB population as a whole, and even further worse than the GA population as a whole. At least the IV-P gives you something in return for the risk you take...

I'm not sure what your definition of a "normal" aircraft is, but while Velocity seems to have achieved adequate cooling with downdraft systems on their aircraft, most LE's, VE's, COZY's, etc. use updraft cooling, as getting sufficient air to enter the engine compartment from on top of the strakes takes a fair bit of engineering, testing and tweaking. Depending upon who you copy, you may get a successful downdraft system, but updraft is far easier to get to be successful.

My $0.02.

[Kent Ashton]

9 hours ago, Henry Bartle said:

I am going to have all the cooling come down from the top and exit the rear, just like normal aircraft. Is there a better way?

I have experimented with downdraft cooling here and in subsequent posts   https://www.canardzone.com/forums/topic/18661-kents-long-ez-project/?do=findComment&comment=47345  but to summarize my experience: 

-Airflow over the top of the strakes or fuselage is not as good when climbing as into a belly inlet so when you need good flow at high power, cooling is not as good.  However,  for cruise, the inlets can be made smaller and use less air than updraft so downdraft is fairly efficient in a cruise situation.

-Exit size and position are as important as inlet design.

-The only good way to figure out if your cooling airflow is good enough is to use a water manometer--discussed in the same thread.