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  #1  
Old 11-17-2013, 01:39 AM
Andrew M's Avatar
Andrew M Andrew M is offline
 
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Location: Secluded Lake,Alaska (AK49)
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Default Stall warning

I am at the point where I am prepping all the stall warning stuff and I got to thinking.....
Imagine two warning systems installed, the first standard, set to go off at 3KTS above stall, the second 8KTS above. Each one piped into a different ear (stereo). This would allow me to fly that "sweet spot" low and slow with my head out of the cockpit, and maneuver.
The advantage is I don't have to have an eye on an AOA, this uses another sense and frees up my eyes.
My question is, is this type system airspeed/weight sensitive...example only works at one load and straight and level, or is it as accurate as an AOA, any airspeed and load, bank angle.
Any other questions I should be asking?
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  #2  
Old 11-17-2013, 03:23 AM
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cfiidon cfiidon is offline
 
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Default

I cannot speak for other systems, but my Dynon D180 with AOA system has progressive settings... the audio alert gets more intensive as the AOA increases.

Critical AOA is independent of weight, bank angle, and speed.

You can review the appropriate chapter of their installation manual. These are available on their website.

Don
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  #3  
Old 11-17-2013, 08:03 AM
sailvi767 sailvi767 is online now
 
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Location: Charlotte NC
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Quote:
Originally Posted by Andrew M View Post
I am at the point where I am prepping all the stall warning stuff and I got to thinking.....
Imagine two warning systems installed, the first standard, set to go off at 3KTS above stall, the second 8KTS above. Each one piped into a different ear (stereo). This would allow me to fly that "sweet spot" low and slow with my head out of the cockpit, and maneuver.
The advantage is I don't have to have an eye on an AOA, this uses another sense and frees up my eyes.
My question is, is this type system airspeed/weight sensitive...example only works at one load and straight and level, or is it as accurate as an AOA, any airspeed and load, bank angle.
Any other questions I should be asking?

This might sound a bit harsh but flying at 3 to 8 knots above stall speed low and slow while maneuvering is a regime I would try and avoid. Set your stall warning for 1.15 above stall speed and stay above it flying low and slow. Preferably well above it. There are thousands of reasons why 1.3 times the stall speed is the minimum normal approach speed, most written in blood.
George

Last edited by sailvi767 : 11-17-2013 at 08:05 AM. Reason: Error
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  #4  
Old 11-17-2013, 08:17 AM
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GeneL GeneL is offline
 
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Default Buy a Cub!

Don't poke the bear in an RV.
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  #5  
Old 11-17-2013, 09:58 AM
Aryana Aryana is offline
 
Join Date: Jul 2012
Location: Western US
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I completely disagree. Being able to fly your plane slow is a key skill, especially for landing.

I recently saw this document posted on the thread for the person that flipped his RV over on it's back and I thought it was a great: http://www.vansairforce.net/safety/HowToLandAnRV.pdf

"Any pilot who is capable of controlling his airplane for a prolonged time within 5 mph of stall speed should have little trouble landing."

The only RV I've landed is an RV-10, and I saw no adverse behaviors that would make me think flying at MCA should be avoided. Judgment needs to be used here though. Don't fly at MCA when conditions aren't favorable. I'd recommend going to a good instructor that has some bush flying experience to help you if you're in doubt.

I like your idea about the different audible warnings. With enough practice, you wont need any stall warning indicator because you will "feel" the stall coming by the seat of your pants after you get to know your plane really well.

This will all come in very handy when/if you ever have an emergency off airport landing. You will want to be very slow when you touchdown in that case.

I too often see folks blazing in on fast airplanes taking 3000 ft + to stop a RV/Bonanza/Cessna when they could have executed a proper full stall landing. Sometimes a long landing is intentional to save on long taxis, but my experience is these folks blazing it in get white knuckled when it comes time to fly the airplane slow. I wouldn't want to be a passenger in their plane when it comes time for them to plop it in a field in an emergency.
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  #6  
Old 11-17-2013, 10:46 AM
sailvi767 sailvi767 is online now
 
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Each person can have their own comfort zone. My aircraft stalls at 50 knots. Flying around low and slow while maneuvering between 53 and 58 knots has little to do with a proper approach and landing. Yes you need to know how to fly slow. You should be comfortable in all modes of flight. At low altitude the only time I want to see 3 knots above stall is with the wheels 1 foot or less above the runway.
I practice slow flight. Actually did a bunch the last two weeks. I don't do it at low altitude. I also practice stalls again at a safe altitude. 3 knots above stall at low altitude while turning ect is a a great way to become a statistic. I don't care how good you are. There is not much to be gained by slowing to 53 knots verses 70 knots where you have some margin for the wife and kids. I don't know anyone who flies approaches at those kind of slow speeds. Starting to slow over the fence to those speeds in a stable configuration for a short landing is a whole different animal then cruising around low and slow and turning at those speeds. One wind gust could ruin your day with a 3 knot margin at 100 feet.

George
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  #7  
Old 11-17-2013, 11:26 AM
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Andrew M Andrew M is offline
 
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Default Reset

All who replied, thanks for helping me consider this idea,
Don, thanks for the link.
Gene, I am flying a Aeronca Chief.
George, reset so first starts at 1.3, second to 1.15.
Anyone, will it perform like AOA, independent of load, airspeed, and bank angle?
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  #8  
Old 11-17-2013, 12:18 PM
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rmartingt rmartingt is offline
 
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Location: Savannah, GA
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That depends on what kind of system it is. If it's set by a given airspeed, it'll basically only be really accurate for 1G flight at a specified weight.

A stall-warning tab (like the kit Van's sells) or an AOA-based sysem like Dynon has should work for all G loads and weights.
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  #9  
Old 11-17-2013, 01:09 PM
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N941WR N941WR is offline
 
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My -9 didn't come with a stall warning and I found the airplane talks so well, it really isn't needed, unless you are deaf.

The AoA in the Dynon, either the classic or SkyView, is spot on, regardless of weight.

I never look at the graphical depiction but rely on the audio beeping, which grows as you approach the stall. It is good enough that I would forgo the weight and complexity of the stall warning that Van's now ships with the kit.
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  #10  
Old 11-17-2013, 01:24 PM
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MS19087 MS19087 is offline
 
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Default I love my AFS AOA, but ...

Would really like a progressive audio warning/ tone. It does give an "angle, angle, push" annunciation at I believe 1.3 Vs. Sure wish advanced could add the tone.
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