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  #1  
Old 05-18-2018, 11:00 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
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Location: Hinckley, Ohio
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Default Stall Warning – 1 Vs. 2 Onboard…

I’ve noticed my stall warning is far less sensitive in the landing flair with only one person onboard with minimal fuel. In the above scenario the landing flair in ground effect is longer and it takes a very pronounced nose-high full-stall landing to get the stall warning to annunciate.

With a second person onboard and ¾ fuel the stall warning annunciates much sooner in the flair and nose of aircraft is not nearly so high an angle.

I have checked stall warning vane geometry and switch setup against drawing 16-03 and everything looks correct.

So, I’m wondering if others are seeing this same thing…
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Jim Stricker
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PPL/ASEL 1970 Sport Pilot since 2004
80 hrs Flying Aeronca Chief 11AC
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  #2  
Old 05-18-2018, 03:40 PM
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rmartingt rmartingt is offline
 
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Location: Savannah, GA
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Quote:
Originally Posted by Piper J3 View Post
I’ve noticed my stall warning is far less sensitive in the landing flair with only one person onboard with minimal fuel. In the above scenario the landing flair in ground effect is longer and it takes a very pronounced nose-high full-stall landing to get the stall warning to annunciate.

With a second person onboard and ¾ fuel the stall warning annunciates much sooner in the flair and nose of aircraft is not nearly so high an angle.

I have checked stall warning vane geometry and switch setup against drawing 16-03 and everything looks correct.

So, I’m wondering if others are seeing this same thing…
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Assuming you're flying the same speeds... I'd think that would be expected, with significantly more weight on the aircraft.
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  #3  
Old 05-18-2018, 05:12 PM
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Sam Buchanan Sam Buchanan is offline
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Join Date: Dec 2004
Location: North Alabama
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Quote:
Originally Posted by Piper J3 View Post
I’ve noticed my stall warning is far less sensitive in the landing flair with only one person onboard with minimal fuel. In the above scenario the landing flair in ground effect is longer and it takes a very pronounced nose-high full-stall landing to get the stall warning to annunciate.

With a second person onboard and ¾ fuel the stall warning annunciates much sooner in the flair and nose of aircraft is not nearly so high an angle.

I have checked stall warning vane geometry and switch setup against drawing 16-03 and everything looks correct.

So, I’m wondering if others are seeing this same thing…
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Sounds like it is working very nicely!

The aircraft is going to stall at more nose-high attitude (slower airspeed) at light weight than when flown with a heavy load. The AOA is doing just what it is supposed to do, telling you what the wing is seeing.

I've been flying AOA in my RV-6 for over 15 years and consider it the primary instrument for landing. Study AOA and understand what it is telling you and it will be a valuable resource.
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  #4  
Old 05-19-2018, 08:34 PM
RFSchaller RFSchaller is offline
 
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Mine stopped working —- can’t say I miss it!😜
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  #5  
Old 05-19-2018, 09:43 PM
rv7charlie rv7charlie is offline
 
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Location: Pocahontas MS
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Hmmm... I'm ready to be (re)educated. Everything I've ever read said that an a/c in any single configuration always stalls at the same AOA, and only the stall airspeed varies.

Last edited by rv7charlie : 05-20-2018 at 12:53 PM.
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  #6  
Old 05-19-2018, 10:28 PM
Mich48041 Mich48041 is offline
 
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Location: Riley TWP MI
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I'm with you Charlie.
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  #7  
Old 05-19-2018, 10:47 PM
BobTurner BobTurner is offline
 
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Location: Livermore, CA
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Me two (also too).
I do think there is the possibility that pilots of light aircraft flare into zero sink rate, while when the airplane is heavy they pull up to the same attitude as light -but that’s insufficient to completely check the descent. Due to the descent the angle of attack is higher than it appears.
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  #8  
Old 05-20-2018, 12:48 PM
sblack sblack is offline
 
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Location: Montreal
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Stall attitude will always be the same but it will happen at lower speed at lighter weight. If you approach at the same speed irrespective of weight you will spend more time in the flare bleeding off the excess speed so you might get to a higher attitude. If you want your approaches to be consistent then fly slower when you are lighter. Multiply your heavy weight approach speed by the square root of the weight ratio i.e (actual weight/max weight). So if you are 10% lighter than full fuel and 2 people, approach 5% slower and it should feel pretty much the same. You would be flying a constant V/Vstall ratio, which is how most larger high performance airplanes are operated.
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