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  #1  
Old 06-15-2022, 03:17 AM
amekler amekler is online now
 
Join Date: Aug 2009
Location: Gilford,NH
Posts: 201
Default stall characteristics

Doing flight testing in my ELSA RV-12 and have noticed a pretty abrupt drop of the right wing in a stall. I have a RV-10 that just shakes the tail and mushes in the stall.
Is this normal for the RV-12?
ps ball is centered and right wing seems a bit heavy

Alan
N603NH
Rv-12 3 hrs so far

Last edited by amekler : 06-15-2022 at 03:18 AM. Reason: fixed wording
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  #2  
Old 06-15-2022, 05:08 AM
rgmwa rgmwa is offline
 
Join Date: Feb 2010
Location: Perth, Western Australia
Posts: 1,716
Default

Adjusting the heavy right wing would be a good place to start. Mine just mushes along in a stall with the ball centered.
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  #3  
Old 06-15-2022, 06:11 AM
WJaviation WJaviation is offline
 
Join Date: Jul 2020
Location: Pensacola
Posts: 61
Default

I had the exact same problem. It was like riding a bull as it dropped to right. In fact sometimes I'd even find coolant that had come out of the vent tube because the negative G during the stall would push it up and out of the overflow bottle. It was a really aggressive stall break to the right.

I had the wing gap seal taped with glider tape as cleanly and as tightly as I could.

Once I finally precisely installed the rubber gap seal provided by Vans, the stall break became a very tame mushing of controls with maaaaybe the slightest break to the right.

I wouldnt start bending wing metal to fix a heavy wing until you've got that final gap seal installed. I'm glad that I decided to wait and see what the "final" stall characteristics were.
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  #4  
Old 06-15-2022, 09:01 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,764
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Yes, I would fix heavy wing first. Then I would check for heavy wing with one notch of flap, and then again with full-flap. In each case, I would trim hands-off for 55 KIAS. My 12 flies level in roll axis at cruise and with flaps extended. Stall is a non-event… both clean and with flaps.

As side note... I have flown plane with and w/o wing root seals and it flies same either way including stalls clean and with flaps....
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Last edited by Piper J3 : 06-15-2022 at 09:03 AM.
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  #5  
Old 06-15-2022, 09:40 AM
amekler amekler is online now
 
Join Date: Aug 2009
Location: Gilford,NH
Posts: 201
Default

Quote:
Originally Posted by WJaviation View Post
I had the exact same problem. It was like riding a bull as it dropped to right. In fact sometimes I'd even find coolant that had come out of the vent tube because the negative G during the stall would push it up and out of the overflow bottle. It was a really aggressive stall break to the right.

I had the wing gap seal taped with glider tape as cleanly and as tightly as I could.

Once I finally precisely installed the rubber gap seal provided by Vans, the stall break became a very tame mushing of controls with maaaaybe the slightest break to the right.

I wouldnt start bending wing metal to fix a heavy wing until you've got that final gap seal installed. I'm glad that I decided to wait and see what the "final" stall characteristics were.

Very interesting.
I also have Glider tape. I have a rudder trim tab that I moved about 1/8 inch to center the ball. I was about to check the rigging but maybe first I should install the seals as there is a 2 year wait at the paint shop
Alan
N603NH
flight test 1-5 completed
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  #6  
Old 06-15-2022, 10:21 AM
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rcarsey rcarsey is offline
 
Join Date: Jul 2012
Location: North Brunswick, NJ
Posts: 361
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Quote:
Originally Posted by WJaviation View Post
Once I finally precisely installed the rubber gap seal provided by Vans, the stall break became a very tame mushing of controls with maaaaybe the slightest break to the right.
I currently have no seals installed and I get a sharp break to the right too. Good to hear that the seals may correct that. (I opted not to install them until it gets painted later this year)
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  #7  
Old 06-15-2022, 10:22 AM
NinerBikes NinerBikes is offline
 
Join Date: Dec 2018
Location: Granada Hills
Posts: 1,285
Unhappy

My RV-12 exhibited the same behavior during power on stalls. It flew straight, regardless of flap position in slow speed flight.

I never really figured out or mastered that right wing drop at power on stall, as I had a lot of right rudder kicked in just to keep the plane on course. My instructor had no problem with it, nor did my fellow RV-12 friend who also flew my plane. Nose just dropped normally, for them, wings level. More experience, more coordination with hands and feet?

There is a normal P effect from the rotation of the prop providing the left wing with more lift than the right wing, therefore the right wing will stall first, it's pretty normal. Some plane wing designs mess up the laminar flow on the leading edge of the left wing such that the plane exhibits equal lift from both wings near stall speed. I don't know if the RV-12 has this engineered into their wing design or not.

I chalked it up as a lack of experience / coordination on my part, because I went and flew a PA28 150, and it's behavior during a power on stall was down right docile, child's play.

Maybe try it a few more times and see if you can get the coordination? My wings buffeted at the root for quite some time before my plane would actually stall and the right wing and nose would drop very quickly.

Or let someone else with an RV-12 fly it to confirm?

i did have proper seals installed.
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Last edited by NinerBikes : 06-15-2022 at 10:59 AM.
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  #8  
Old 06-15-2022, 11:00 AM
azonslow azonslow is offline
 
Join Date: Mar 2017
Location: Maricopa County, AZ
Posts: 15
Default Heavy Wing

Over the years there have been many posts regarding heavy wing (usually as I recall the right wing). I suggest your read Vans PAP regarding "Lateral (roll) trim". If you have that kind of issue, the procedure outlined will fix the problem. It did for me. Some have reported successfully using a trim tab on one wing.
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  #9  
Old 06-15-2022, 11:12 AM
AeroDog AeroDog is offline
 
Join Date: Aug 2011
Location: New London, NC (near Charlotte), Longmont, CO
Posts: 335
Default

Quote:
Originally Posted by WJaviation View Post
I had the exact same problem. It was like riding a bull as it dropped to right. In fact sometimes I'd even find coolant that had come out of the vent tube because the negative G during the stall would push it up and out of the overflow bottle. It was a really aggressive stall break to the right.

I had the wing gap seal taped with glider tape as cleanly and as tightly as I could.

Once I finally precisely installed the rubber gap seal provided by Vans, the stall break became a very tame mushing of controls with maaaaybe the slightest break to the right.

I wouldnt start bending wing metal to fix a heavy wing until you've got that final gap seal installed. I'm glad that I decided to wait and see what the "final" stall characteristics were.
I can't think of a reason there would be a difference between glider tape and the rubber seals.

Jerre
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  #10  
Old 06-15-2022, 11:27 AM
WJaviation WJaviation is offline
 
Join Date: Jul 2020
Location: Pensacola
Posts: 61
Default

Completely agree. But the only thing that's changed is my root seals. And my stalls are mild and comfortable now as compared to the right wing dive.
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