the dreaded base to final turn

[Andy95W]

Yes, but good recurrent training does the same thing and costs less.

I hear this stated so often to any discussion of good aeronautical discussions.  Can't we have both?  Good training and good instruments? 

My original post was meant to address the tendency of pilots (me included) to always want the biggest/best/newest/coolest pieces of equipment in our airplanes, from big-ass pilot watches to the latest panel mount GPS or Aspen displays.

Most of us do believe in Flight Safety's motto:

"The best safety device in any aircraft is a well-trained pilot."

If the goal of safety devices is to make our flying safer, then the end result could be achieved by training.

An idiot with an AOA indicator will still find a way to stall his airplane at low altitude, or worse yet, focus so entirely on the AOA he doesn't see another airplane on the runway as he's about to land.

And I completely agree we should have both good training and good devices. i have already decided which AOA I'm going to get.

[PTK]

This thread is a discussion on the "dreaded" base to final turn. Why is it dreaded? Precisely because it kills.

 

Another gadget in the panel is not going to save the day here for the pilot who doesn't know what he/she doesn't know.

 

On the contrary, I strongly feel it will be a distraction and may end up killing the pilots who would be otherwise inclined to go around.

 

Money spent on constant training is money wisely spent.

[rq3]

Do you have any pictures of an installation on a mooney by chance?

This gentleman mounted the display in a box on the glareshield, rather than in the panel:

http://mooneyspace.com/topic/10120-cya-100-aoa/

 

Rip

[alex]

I like it!   I'm in.

 

1) Where are the buttons to calibrate I don't see any on the LED display, Is there a separate unit for that?

 

2) I watched the demo video and in it you have the LED's next to the ASI, I like that setup. How would you feel about installing the LED display the opposite direction so that as you are pulling back on the yoke the LED's  end up on the red? Is that not a good idea? If not why?   Thanks

[Bob_Belville]

...If you are in level flight in my aircraft at say, 75 kts., and you quickly bank to 60 and the aircraft remains in level flight (no descent), the aircraft will stall immediately.  

 

But if you make this abrupt maneuver at this relatively low speed you will not be in level flight unless you hold back on the yoke. That's my point... it is not (just) the bank angle that gets you in trouble, it's trying to maintain the rate of descent while reducing the lift of the wing which defies physics. OTOH, if I need to make a tighter turn, as I had to when landing @ SunNFun, knowing that the stall speed will increase and the vertical speed will increase I would need to add power instead of pulling back on the yoke.

 

But I would not think anyone, certainly not me, would endorse 60 deg bank @ 400' AGL @ 75 kts. That a crazy premise. 

 

 

This horse is probably bloody enough... 

[Bob - S50]

Bob, I am trying to respond to your post on P. 3 of this thread and can't get my system to copy it.  But here are my thoughts, for what they are worth. 

 

"Bank angle in itself will not cause a stall."  I think what you mean to say is that if you increase bank, let's say from level to 60 degrees, and let the nose fall as it wishes, there will not be a stall.  That would be true to a point, but bank angle in itself does cause a stall.  If you are in level flight in my aircraft at say, 75 kts., and you quickly bank to 60 and the aircraft remains in level flight (no descent), the aircraft will stall immediately.  That is how accelerated stalls are done.  It is true that if you let the nose fall, you may be able to stay out of a stall, but my experience with steep spirals tells me that even nose down and descending you can stall at 60 degrees.  We don't have any numbers to go by to know if a 750 fpm descent rate will keep us out of the nose down stall where a 500 fpm rate will not, in others words unloading the wing can prevent the stall but we have no way of knowing how much to unload except what the stall horn is telling us. This stall will happen whether you stay coordinated or not.  Accelerated stalls also tend to be more rapid and require a quicker response to prevent a spin. 

 

On another issue I see raised in the thread, quite a lot of us fly the pattern at 90 downwind, 80 or 85 base, and then 75 or 80 on final.  That base to final turn is going to be in the 80-85 kts. range.  Obviously, there are a lot of different Mooney types and some want more speed than others, thus the range.  That is less than the level flight, flaps extended, 60 degree bank stall speed of my aircraft, and all of our aircraft that I am aware of.  It is true that if you are nose down you can mitigate the issue some, but from experience you need to be aggressively nose down not just a little nose down, and at that point in your descent you are probably 400 AGL, so aggressive nose down is really not an option.  My point is that 60 degrees of bank in a base to final turn in our aircraft, coordinated or not and nose down or not, will generally not end well.  Honestly, I think Mooney pilots need to think in terms of a maximum of 45 degrees in that turn, and even that would be a "performance" turn, 30 is a lot safer.

 

Keep your patterns big and use no more than 30 degree turns.  We would all much rather that everyone do that and then come back and argue LOP/ROP with us here in this forum,  than the alternative. 

 

jlunseth,

 

I think we are on the same page.  We both agree that bank angle will not make you stall.  What makes you stall is AOA.  The thing about bank angle that makes you stall is when you try to maintain the flight path you were previously on, be that level flight or base turn.  Given enough altitude, I can bank to 90 degrees and I won't stall, as long as I don't increase the wing loading.  But I'm going to run out of altitude pretty quickly.  At 80 knots I can be upside down at one G and I won't stall but the nose is going to come down pretty quickly.  As a matter of fact, fighter pilots love upside down.  One G upside down will make the nose track as fast as 3 G's right side up because gravity is helping you instead of fighting you.

 

As you said, the thing about increasing bank angle in the base turn is the fact that you will have to increase AOA/G's/wing loading to maintain your current flight path.  Do that too much and you will stall.

 

To make things even worse, if you are overshooting, you now have further to fly than you would if you had intercepted final.  For any given altitude this will flatten the approach path.  Instead of just trying to maintain your flight path, you'll probably actually try to bring the nose up to shallow out the approach.  This will require even more wing loading and because of the shallower flight path, speed will bleed off even faster (unless you add power to maintain speed).

 

I tend to not live by absolutes so I won't say I'll never exceed 30 degrees of bank on base.  As a matter of fact I never even look at my attitude indicator in the pattern.  I'm focused on the runway, my flight path, and my airspeed.

 

As I said elsewhere, I do tend to fly fairly wide patterns, I am not afraid to go around, and don't care if I get a ribbing about it.

 

A superior pilot is one who uses their superior judgement and superior planning to avoid situations requiring their superior skill to save their superior posterior.

 

Bob

[rq3]

I like it!   I'm in.

 

1) Where are the buttons to calibrate I don't see any on the LED display, Is there a separate unit for that?

 

2) I watched the demo video and in it you have the LED's next to the ASI, I like that setup. How would you feel about installing the LED display the opposite direction so that as you are pulling back on the yoke the LED's  end up on the red? Is that not a good idea? If not why?   Thanks

 

Many thanks, Alex. You can download the Installation and Operation Manual from the link at the top of the "Tech" page on my website:

http://www.ackemma.com/index.html

 

The display is designed to be flush mounted behind the panel, but as you can see that's not always where it ends up! It was also designed to be

a "command" instrument, like a glideslope needle. The nose follows the needle, or in this case the LED. Again, I've seen them mounted up-side down, and even sideways (which would personally drive me nuts).

 

The programming switch is a simple pushbutton switch. The FAA requires that it be removed after programming. Does everyone actually do that? Well, um....

 

Rip

[ArtVandelay]

I noticed the CYA was $395 in early 2014, now $625, was there a change in design to correspond with the price increase?

[rq3]

I noticed the CYA was $395 in early 2014, now $625, was there a change in design to correspond with the price increase?

 

Several factors led to the price increase. The biggest one is the hefty cut my distributor takes.

There have been design changes too (like brighter LEDs) which didn't help the price, but enhance the product.

Originally the circuit boards were done in small batches, but are now done in larger batches (lower cost), but are gold plated (higher cost).

Ideally, I'd like these things to outlast the aircraft while keeping the price within the realm of reason.

Rip

[slowflyin]

Do you have any pictures of an installation on a mooney by chance?

Here is one - left of the AS

http://mooneyspace.com/gallery/image/35878-left-panel/

[wishboneash]

Here's a picture of my install. The wiring is now not visible. 

http://mooneyspace.com/gallery/image/35355-cya-100-normal-flight-conditions/

If I redo the panel, it will go into the panel flush mounted.

[Andy95W]

Any airspeed loss with the installation of the CYA or any other AOA device?

[rq3]

Any airspeed loss with the installation of the CYA or any other AOA device?

 

There has to be, because the probe adds drag. The CYA-100 probe is roughly the size of a transponder or DME blade antenna, with a drag of less than 0.7 pound at 250 knots. You certainly won't notice it on the airspeed indicator or GPS.

 

Rip

[aviatoreb]

There has to be, because the probe adds drag. The CYA-100 probe is roughly the size of a transponder or DME blade antenna, with a drag of less than 0.7 pound at 250 knots. You certainly won't notice it on the airspeed indicator or GPS.

 

Rip

 

Yup - more generally this is called the "observer effect" in physics - its even related to Heisenberg's uncertainty principle.  You tend to upset any system you are trying to observe (measure).  The classic example is that if you want to measure tire pressure you let a little pressure out of the tire to measure it in the measuring tool - thus changing the pressure you are trying to measure.  Here your AoA is changing the speed of the airplane by hanging a probe out in the wind to measure it, and in so doing changing  speed and related to it the AoA you are trying to measure.

 

http://en.wikipedia.org/wiki/Observer_effect_%28physics%29

[rq3]

Yup - more generally this is called the "observer effect" in physics - its even related to Heisenberg's uncertainty principle.  You tend to upset any system you are trying to observe (measure).  The classic example is that if you want to measure tire pressure you let a little pressure out of the tire to measure it in the measuring tool - thus changing the pressure you are trying to measure.  Here your AoA is changing the speed of the airplane by hanging a probe out in the wind to measure it, and in so doing changing  speed and related to it the AoA you are trying to measure.

 

http://en.wikipedia.org/wiki/Observer_effect_%28physics%29

 

Funniest thing I've read this week! Eventually your Mooney will collapse into a black hole, and reach Warp 11 (the fastest you can go without the Quantum 2 Warp drive, but I'm working on it). Of course, ADS-B is then worthless, because you arrive at your destination before you leave.

 

Rip

[aviatoreb]

Funniest thing I've read this week!

 

But its true!  :-)  Take it from an old math professor imitating a physics professor.

 

Funniest thing I've read this week! Eventually your Mooney will collapse into a black hole, and reach Warp 11 (the fastest you can go without the Quantum 2 Warp drive, but I'm working on it). Of course, ADS-B is then worthless, because you arrive at your destination before you leave.

 

Rip

 

Will the CY-100 work at warp factor 11?

[bonal]

Funniest thing I've read this week! Eventually your Mooney will collapse into a black hole, and reach Warp 11 (the fastest you can go without the Quantum 2 Warp drive, but I'm working on it). Of course, ADS-B is then worthless, because you arrive at your destination before you leave.

 

Rip

I'm still waiting for you guys to get here.

[rq3]

But its true!  :-)  Take it from an old math professor imitating a physics professor.

 

 

Will the CY-100 work at warp factor 11?

 

No, sadly, Scotty told me that the vane will revert to pure neutronium at warp 10.8

[bonal]

No, sadly, Scotty told me that the vane will revert to pure neutronium at warp 10.8

Some how the Kelvins solved this problem.

[Andy95W]

Yup - more generally this is called the "observer effect" in physics - its even related to Heisenberg's uncertainty principle.  You tend to upset any system you are trying to observe (measure).  The classic example is that if you want to measure tire pressure you let a little pressure out of the tire to measure it in the measuring tool - thus changing the pressure you are trying to measure.  Here your AoA is changing the speed of the airplane by hanging a probe out in the wind to measure it, and in so doing changing  speed and related to it the AoA you are trying to measure.

 

http://en.wikipedia.org/wiki/Observer_effect_(physics)

Yeah...

I was really just interested in how much speed I would lose. I do fly a Mooney for a reason, after all.

[rq3]

Yeah...

I was really just interested in how much speed I would lose. I do fly a Mooney for a reason, after all.

 

All of the probes are roughly equal in drag to a very short antenna. Not only will you NOT notice a decrease in airspeed,

you don't have the instrumentation to measure it. It will be someting like 1 gallon of avgas per 1000 hours.

[carusoam]

Rip,

I appreciate your gentle, calm, knowledgable, helpful style.

Question: From your experience, when do pilots TAKE THEIR last look at the ASI or AOA on short final?

I noticed the other day while landing, it was further back then I expected. Once looking at the rwy numbers it becomes challenging to look out the side window, instruments and front window in a quick scanning format...

Wondering if you have some recommendations or knowledge of how other pilots use your instrument...

Best regards,

-a-

[PTK]

Yup - more generally this is called the "observer effect" in physics - its even related to Heisenberg's uncertainty principle. You tend to upset any system you are trying to observe (measure)...

Yeah...

I was really just interested in how much speed I would lose. I do fly a Mooney for a reason, after all.

Mathematically the Heisenberg uncertainty principle basically relates the errors in position and momentum to the Planck's constant: (ΔxΔp>h/2π)

It says that the error in position (x) multiplied by the error in momentum (p) is greater than Planck's constant, h.

Planck's constant is a very miniscule quantity, 6.626176 x 10⁻³⁴ joule-seconds. Because of this the H. uncertainty principle is unimportant to our large macroscopic world we're accustomed to. We can measure, for example, the position and velocity of a car or plane because the uncertainty as implied by the Heisenberg uncertainty principle is too small and insignificant. It is significant when we talk about the masses of atoms and subatomic particles.

The uncertainty of the position of a hit golf ball or baseball for example is in the order of 10⁻³⁰ mm. That's a miniscule fraction of a millimeter!

[aviatoreb]

Mathematically the Heisenberg uncertainty principle basically relates the errors in position and momentum to the Planck's constant: (ΔxΔp>h/2π)

It says that the error in position (x) multiplied by the error in momentum (p) is greater than Planck's constant, h.

 

 

Quite right!

 

 

Planck's constant is a very miniscule quantity, 6.626176 x 10⁻³⁴ joule-seconds. Because of this the H. uncertainty principle is unimportant to our large macroscopic world we're accustomed to. We can measure, for example, the position and velocity of a car or plane because the uncertainty as implied by the Heisenberg uncertainty principle is too small and insignificant. It is significant when we talk about the masses of atoms and subatomic particles.

The uncertainty of the position of a hit golf ball or baseball for example is in the order of 10⁻³⁰ mm. That's a miniscule fraction of a millimeter!

 

Heisenberg's uncertainty principle is the absolute limit of the measurability of physics quantities no matter how clean you try and make your experiment.  Momentum and position simply do not both exist to ultra high precision beyond a certain point in a measurable sense do to quantum "blur".

 

That does not prevent you from making messier measurements in real life experiments.  That is what the "observer effect" is about.  As I said the classic example is you extract a small amount of air from a tire when measuring pressure thus changing the value of what you are measuring.  This error is much much bigger than the scales suggested by Planck's constant.  Try and make a smaller chamber in the pressure measuring device - sure - but we are not tickling Heisenber's uncertainty principle in these sorts of things - but they do struggle with that sort of scale in modern chip etching.

[PTK]

Quite right!

Heisenberg's uncertainty principle is the absolute limit of the measurability of physics quantities no matter how clean you try and make your experiment. Momentum and position simply do not both exist to ultra high precision beyond a certain point in a measurable sense do to quantum "blur"...

Agreed. A basis of quantum theory is this concept of a wave function, advanced by Schrodinger, describing all possible states a particle can have. Taking position of the electron around the Hydrogen nucleus as an example, we don't know for sure where it is so we accept it can exist, simultaneously, anywhere around the nucleus. This is based on probability. We don't know so we must include all probabilities. The only way to know is to observe it. And for the sub-atomic level we know through observation of interference this actually occurs. A particle can be in many places simultaneously. Or more correctly there's a non -zero probability of finding it in a certain position should we observe it. (Dirac)

But this only works with quantum theory. It does not work in our macro world.

I'm with Schrodinger and his cat!