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delta4242

AOA Horn

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Hey Guys-

I’ve flow my new to me plane about 15 hours since I bought her a few months ago. One thing I’ve noticed is that the AOA horn seems to start going off (small beeps) around 62-65 knots on approach with 15 degree flaps. If I stay above this speed I don’t hear it again until the flare/ touchdown. I could live with this, but what’s strange is that after touch down it seems to stay on (solid horn) till I slow down to roughly 20-25 knots. Is that normal?

It’s a 2018 CTLSI 

Thanks

 

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Welcome to the CT Family! I've been an owner for two years now and after almost 200 hours on my CT I can say I love it as much as I did the day I got it!. While I don't get this on approach to land I get the AOA buzzer going off on 1 of every 5 rollouts on takeoff. Not exactly sure why either so I'll keep an eye open as to what others think your problem may be and maybe we can both figure this out!

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Thanks for the response. I looked at all the holes around both pitot tubes and it does look like 1 hole is blocked on the left pitot. Looks like epoxy from the pitot cap got into the hole. 
I don’t know if this is enough to cause this as the other 5 or 6 holes are clear.
 

9859D99A-9CD7-4A42-BA90-B3FB8995C4A5.jpeg

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I have the D100/D120 units in my 2010 CTLS. The installation manual for the D100 includes a section on calibrating the AOA system, prescribing a flight including stalls at different flap settings while pushing the proper buttons on the D100.  I’m guessing that the installation manual for your EFIS includes a similar procedure. I’ve not done this with my airplane but am planning to try it, since my AOA warning never buzzes except early in the takeoff run.  I suppose it’s possible that FD has locked this up to make it inaccessible.  Food for thought if the plugged hole doesn’t turn out to be the problem. 

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Delta,

What instrumentation system do you have in your panel, Dynon, or Garmin? 

Not all CT's are the same, and some have different equipment installed. People are willing to help, but most can only give information on the equipment their airplanes have. From the picture you posted of the pitot, it is an indication that you may have something other than Dynon installed. That is not the standard Dynon pitot tube. The small holes behind the head of the pitot is likely the static source for your instruments. 

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That looks like the heated pitot I bought from FD a couple of years ago.  There are pictures and a discussion on this site.  Search on "heated" and look for 2006 CTSW IFR or something like that.

 

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9 hours ago, Tom Baker said:

Delta,

What instrumentation system do you have in your panel, Dynon, or Garmin? 

Not all CT's are the same, and some have different equipment installed. People are willing to help, but most can only give information on the equipment their airplanes have. From the picture you posted of the pitot, it is an indication that you may have something other than Dynon installed. That is not the standard Dynon pitot tube. The small holes behind the head of the pitot is likely the static source for your instruments. 

Tom, it’s the Dynon

 

47585311-53F1-4871-8861-25A39E1CD78A.jpeg

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Calibration procedure for the pitot static system and AoA is found in the Skyview Installation Manual at https://dynonavionics.com/skyview-documentation.php

In the current revision (AI), see page 5-22. Perform the ZERO PRESSURE IAS/AOA CALIBRATION first, and then the AOA CALIBRATION just above it.

Be advised, the full flap power on stall portion, if it has you do that, will cause you to run out of rudder authority just before stall, risking a spin. One wing will drop VERY HARD if you perform this too slowly. Make sure you understand how to perform spin recovery.

You can minimize this issue by ensuring you load your aircraft as heavy as legally possible (and balanced per limitations), because heavily loaded aircraft are closer to stall than lightly loaded ones. Critical AoA is what this calibration procedure is testing, and that changes with the airfoil, not the loading.

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I guess I'll take my plane out in a few days and check out it's stall characteristics.  I've done many full power stalls with full flaps and have not noticed a lack of rudder authority or tendency to drop a wing if the controls are coordinated (of course, at high AOA and power setting, the ball will not be in the center).

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There's a lot of factors in play, but for the two CTLS I had to do this procedure on, I ran out of rudder both times. I'd just give the stick a quick small pull back to accelerate the stall so I don't stay in a full over state.

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On 9/2/2021 at 12:15 AM, Jim Meade said:

I guess I'll take my plane out in a few days and check out it's stall characteristics.  I've done many full power stalls with full flaps and have not noticed a lack of rudder authority or tendency to drop a wing if the controls are coordinated (of course, at high AOA and power setting, the ball will not be in the center).

Was thinking this same thing! No matter how many times I try to do an aggressive power on stall it's never enough to get me to drop a wing violently let alone enter a spin. 

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