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  #1  
Old 08-22-2020, 12:26 PM
iaw4 iaw4 is offline
 
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Location: Los Angeles, ca
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Default RV6A Wing-Stall Landings

dear RVers---I thought I would share a flying experience here for newcomers to Vans RV airplanes.

it surprised me a little that the stall in an RV6A appears more sudden than a stall in an RV9A. I had expected that the relevant speeds would just all be a little higher. This bit me in an attempt of a demonstration of a full-stall landing from a misjudged 3 feet altitude. the airplane suddenly dropped and the front-wheel needed a repair afterwards.

this is *not* a safety issue.

in the air, it is easily corrected by releasing back pressure.

on normal landing, it is easily avoided by flying reasonable landings, rather than insisting on wanting to have the main wheels touch with a wing stall (and miscalculating the altitude). there is also only a limited angle before a tail strike happens in a 6A.

I hope this helps other pilots.

/iaw
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Old 08-22-2020, 01:27 PM
gasman gasman is offline
 
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Quote:
Originally Posted by iaw4 View Post
dear RVers---I thought I would share a flying experience here for newcomers to Vans RV airplanes.

it surprised me a little that the stall in an RV6A appears more sudden than a stall in an RV9A. I had expected that the relevant speeds would just all be a little higher. This bit me in an attempt of a demonstration of a full-stall landing from a misjudged 3 feet altitude. the airplane suddenly dropped and the front-wheel needed a repair afterwards.

this is *not* a safety issue.

in the air, it is easily corrected by releasing back pressure.

on normal landing, it is easily avoided by flying reasonable landings, rather than insisting on wanting to have the main wheels touch with a wing stall (and miscalculating the altitude). there is also only a limited angle before a tail strike happens in a 6A.

I hope this helps other pilots.

/iaw
Most all of my landings in my 6A are full stall, and I have NEVER touched the tail. So the limited angle of the 6A which is greater than the 6, is more than needed if properly flown.

Now, if I jumped into a 9A and demonstrated a full stall landing for the first time, I might be in for a surprise.................
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  #3  
Old 08-22-2020, 01:36 PM
SPX SPX is offline
 
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Quote:
Originally Posted by iaw4 View Post
dear RVers---I thought I would share a flying experience here for newcomers to Vans RV airplanes.

it surprised me a little that the stall in an RV6A appears more sudden than a stall in an RV9A. I had expected that the relevant speeds would just all be a little higher. This bit me in an attempt of a demonstration of a full-stall landing from a misjudged 3 feet altitude. the airplane suddenly dropped and the front-wheel needed a repair afterwards.

this is *not* a safety issue.

in the air, it is easily corrected by releasing back pressure.

on normal landing, it is easily avoided by flying reasonable landings, rather than insisting on wanting to have the main wheels touch with a wing stall (and miscalculating the altitude). there is also only a limited angle before a tail strike happens in a 6A.

I hope this helps other pilots.

/iaw
Your experience in the 6A is different from my experience in the 6A. I am curious.. have you stalled this aircraft at altitude, and if so, how would you describe its mannerisms in the stall at altitude?
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  #4  
Old 08-22-2020, 11:43 PM
iaw4 iaw4 is offline
 
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I am not a particularly good pilot, having gone back to flying just recently after a 10-year hiatus. what I don't have in skill right now, I make up in chicken-ness.

I found the RV-6A fairly difficult to stall to begin with. I had to point the nose almost sky-high. I only did it once, though. my personal flying rule is to avoid stalls to begin with. I want to automatically push the stick forward *before* I get into a stall. I follow this:

https://flightchops.com/wp-content/u...-FINAL-V5a.pdf

in my mind, a stall at landing was the only good time for a stall.

on this particular day, I did misjudge my altitude at my full stall landing, pulling the stick back further and further, but instead of being inches above the ground, I think I was about 3' above the ground. I recall the rv9a continuing to lose altitude gradually when holding the stick back "forever"; the rv6a seemed more sudden.

later, on the ground, I did lean back on the tail once to check the angle at which the tie-down ring touched the ground. The critical stall angle in ground effect seems steeper than the one for a tail strike. But I won't find out---one attempt was enough for me. I am now going to land it the safe and easy way, at a speed of 60 knots and a very low 50fpm descent rate.
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  #5  
Old 08-23-2020, 06:33 AM
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AlexPeterson AlexPeterson is offline
 
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I recall from many years ago that the 6A's stall angle of attack would cause the tail to hit. This may not be true when in close ground effect with full flaps.

There most certainly is a point at 1' or 2' of altitude where it will simply stop flying and plop down.

The stall at altitude is very different than from a few feet. At a foot or two, it is only salvageable with a quick pulse of power.

I have found that maintaining a constant deck angle for the last few feet is the best way to have consistent landings, using only a slight burst of power to soften the touchdown if necessary. YMMV.

I will try to get data on the deck angles at stall, at altitude, when in level flight and in different configurations. I also want to know deck angle at tail contact vs whatever angle I typically have on touchdown.
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  #6  
Old 08-24-2020, 12:01 AM
iaw4 iaw4 is offline
 
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that's exactly what it did in my case. about 2' up, I pull the stick back and back and back, and it suddenly without warning started to fly vertically---not like near-stall flight at altitude. is it just my impression that an rv-9a or piper cherokee have less sudden drops?

all of this is really easily avoidable by just flying reasonable landings and not trying for a full-stall main-wheel landing. there is really no reason to do this anyway. other than my wallet, it hurt my pride.
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  #7  
Old 08-24-2020, 01:17 PM
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RV8JD RV8JD is offline
 
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Here are some articles by Van himself that may be of interest.
Articles: "How to Fly an RV", "How to Land an RV", "How to Land an RV, Part 2", and "How to Fly a Nose Gear RV".
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Last edited by RV8JD : 08-24-2020 at 01:19 PM.
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  #8  
Old 08-24-2020, 11:44 PM
iaw4 iaw4 is offline
 
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nice articles. for those about to start flying,

[1] landing an rv6a is really easy, unless one insists on demonstrating a full-stall landing and misjudges altitude;

[2] the stall onset in ground effect seems to be a little more sudden on short-wing aircraft like the 6a than it is on longer-wing aircraft; and

[3] transition training is always a good idea no matter how good one is.
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  #9  
Old 08-25-2020, 06:37 AM
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snopercod snopercod is offline
 
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Quote:
Originally Posted by iaw4 View Post
on normal landing, it is easily avoided by flying reasonable landings, rather than insisting on wanting to have the main wheels touch with a wing stall ...
Oh, you've gone and done it now. I was roundly beaten about the head and shoulders for offering that I usually "fly my Lancair on" rather than attempting a full stall landing. I made that decision for exactly the reason you mentioned: It's hard on the nose gear when the stall breaks and the nose slams down.
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  #10  
Old 09-07-2020, 12:44 PM
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AlexPeterson AlexPeterson is offline
 
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Default Pitch Angle Data

With the data from the G3X, I created the following plots.

This is one with the aircraft in the hangar. I simply pushed the tail down to within about 1/2" of the floor and returned it (no tail tie-down eye in place):



This data is during several seconds of the landing phase:



Discussion: I made special note of forward visibility just at the point of touchdown. I'm 72" tall, 34" inseam, Bose headset maybe 1" from the canopy. Just before touchdown, I lost the horizon (head not tipped up), and my eyes immediately went perhaps 20 degrees left for the next couple seconds. The pitch angle was almost 9 degrees. Note that this is about 5 degrees away from tail striking, assuming no landing gear deflection. Note also that the stall warning was not going off.

I believe a firm, full stall landing in the 6A could put the tail within striking distance of the ground.

Thumbnails for posterity:
Attached Thumbnails
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Name:	N66AP Pitch Angle at Touchdown 7SEP20.jpg
Views:	34
Size:	77.0 KB
ID:	2135  Click image for larger version

Name:	N66AP Pitch Angle at Tail Touching 7SEP20.jpg
Views:	29
Size:	58.5 KB
ID:	2136  
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