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  #1  
Old 04-21-2010, 10:59 AM
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Default Deep Stall

Well i have it on good authority that weeks before the incident he was informed that because his rotation speed was high, he needed to change the incidence of the canard.

Also was told that in cruise his elevators were on the wrong side of the canard. Forget wether they are supposed to be up or down. That is a very good indication that the canard is not set correctly.

A buddy of mine has the same problem and he has ignored it, until now. I reamed him for allowing such a sever safety problem to remain. I don't care for the statement "it works for me" just means he has been lucky for 400 hours flight.

FIX THE F'N PLANES

Make safety your prime concern, don't justify it away
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  #2  
Old 04-22-2010, 01:06 AM
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Default Re: Deep Stall

cant get my head around this one......up,down, ex-pain it pee's
me no get it...
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edited by steve for a good reason
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  #3  
Old 04-22-2010, 10:08 AM
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Default Re: Deep Stall

well, in straight level cruise, the elevator is supposed to be up about 1/8 inch. If not the canard is set at too low an angle.

BUT, don't believe me, i'm sure Nat covered this many times and it is probably in the poh.

For us builders, just put the canard in per plans, BUT, when you are in the test flying mode, take that mode serious and make sure the canard is set properly. Well, make sure everything is set properly for that matter.
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  #4  
Old 05-06-2010, 09:40 AM
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Default Re: Deep Stall

From Nat Puffer via Marc.

Just posted it to keep in my memory

Quote:
If the canard is at the right angle of incidence, the elevators will be in trail or slightly trailing edge up in cruise at mid. c.g.
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  #5  
Old 05-07-2010, 06:24 PM
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Default Re: Deep Stall

Quote:
Originally Posted by Dust View Post
Well i have it on good authority that weeks before the incident he was informed that because his rotation speed was high, he needed to change the incidence of the canard.

Also was told that in cruise his elevators were on the wrong side of the canard. Forget wether they are supposed to be up or down. That is a very good indication that the canard is not set correctly.

A buddy of mine has the same problem and he has ignored it, until now. I reamed him for allowing such a sever safety problem to remain. I don't care for the statement "it works for me" just means he has been lucky for 400 hours flight.

FIX THE F'N PLANES

Make safety your prime concern, don't justify it away
Dust, it is true there were some things about my plane that I didn't think were quite right. I discussed them with several folks in the canard community prior to the incident. We discussed them because I brought them up because I was trying to figure out what it was. Some said it "could" be the incidence and some didn't necessarily think so. I thought the rotation speed was a bit high but others told me it was about right. The same goes for approach speed. I don't remember anyone making it out to be a big safety issue at all. Noone mentioned anything about info in the newsletters. I had read through my POH many times but I didn't find out that I was missing an important update until after it was too late. Had I read these things or known 1/10 of what I know now I would have grounded the airplane, plain and simple. You can ask anyone that knows me, I had already grounded it a number of times for far lesser issues.

The whole point of that particular fateful flight was to determine the minimum speed of my Cozy at min weight and aft CG, still within the allowable envelope, however. I had no intention of going beyond its already tested limits. I was looking for good numbers for comparison and trying to figure out what was going on. Also, I had planned on installing vortex generators later in order to get it to slow down more. All of this was done in the name of making it a safer airplane. I didn't think I was anywhere near a deep stall due to the fact that I was 17 knots above the minimum speed posted in the POH and the CG was not aft of the limit.

Anyway, I agree with you in the sense that if you have a known problem that is a potential safety issue, get it fixed. Don't mess around, these little airplanes can kill you in an instant. In my case, I had some suspicions that something wasn't quite right but I wasn't really sure what it was. I had different opinions from several folks, none of which made it out to be a big safety issue. I certainly was not throwing caution to the wind and justifying it away. I was trying to figure out what the problem was.

-Steve
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  #6  
Old 05-07-2010, 08:36 PM
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Default Re: Deep Stall

Thank you Steve. It is always a pleasure to get the "rest of the story".

Your catastrophe will probably save the bacon of many! That was the true intent of my post.

Yours is a sad story of not being informed of the correct information, after trying to obtain it.

So glad you lived through it, breaks my heart that you had to suffer during the event and after.

Another note, i've learned that is your ailerons are both slightly up on the ground so that under pressure they both go down to wing level in flight, this condition also helps increase main wing lift.
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  #7  
Old 05-08-2010, 03:04 PM
argoldman argoldman is offline
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Default Re: Deep Stall

Quote:
Originally Posted by Dust View Post

Another note, i've learned that is your ailerons are both slightly up on the ground so that under pressure they both go down to wing level in flight, this condition also helps increase main wing lift.
NOt quite true, dust. Since the ailerons are connected together, going in opposite directions, the only thing that happens when they are either reflexed up or down is, in the absence of a great deal of slop, that they put torque on the whole mechanism and in effect, eliminate the movement due to the slop. IIf they both go down to wing level, either there is an incredible amount of slop in the system, in which case the aircraft shouldn't be flown, or the amount of reflex is so tiny so as not to make any difference.

Now as to the fact that reflexed ailerons (upward) increase main wing lift, I think that you have that backwards or wing flaps would deploy on the top of the wings, rather than the bottom. Reflexed ailerons actually decrease the camber of the wing and decrease the lift of the wing.
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  #8  
Old 05-09-2010, 12:36 AM
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Default Re: Deep Stall

looks like you are right, but most have mentioned quite a bit of slop.

I reviewed taper pins with my A&P and will, eventually replace all appropriate bolts with them, after i am flying, sick of mods for the moment.
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dust

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  #9  
Old 05-23-2010, 12:31 PM
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Default Re: Deep Stall

Quote:
Make safety your prime concern, don't justify it away
Really? Then why this...
Quote:
eventually replace all appropriate bolts with them, after i am flying, sick of mods for the moment.
Sounds like you're rushing things.
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  #10  
Old 05-23-2010, 03:32 PM
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Default Re: Deep Stall

you are right
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dust

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