The physics of reduced incidence towards the wingtips

[MAKG1]

What's that?

The question popped in my head when I was looking at a photo a cirrus w its split leading edge. They go fast.

The phrase "rate of speed" drives some people nuts. Speed is a rate. It's redundant.

It's kinda like "airspeed velocity" but I've only heard that in one context.

 

[nauga]

It's kinda like "airspeed velocity" but I've only heard that in one context.

African or European?

Nauga,
who is using coconuts

 

[SixPapaCharlie]

I could have meant high rate of some movie on rotten tomatoes
Or rate of acceleration
Or rate of inflation of our currency

Always good be specific irregardless of the task at hand.
ATM machine!

 

[N801BH]

I could have meant high rate of some movie on rotten tomatoes
Or rate of acceleration
Or rate of inflation of our currency

Always good be specific irregardless of the task at hand.
ATM machine!

Or Hot Water Heater....

 

[Dan Thomas]

IIRC, the hershy wing Cherokees have little or no washout. Still the wingroot stalls first, and in my old Cherokee 140 the ailerons were still effective in a stall.

The planform of the wing determines stall progression, and washout (or airfoil mods, as in the Cirrus) corrects those that present difficulties. The rectangular wing is often built without any washout at all.

Dan

 

[coloradobluesky]

A good example of necessary compromises in developing design. The aileron, invented by Alexander Graham Bell for Curtiss, was clearly better than wing warping but the Wrights, in patent battles with Curtiss, clearly couldn't adopt them and infer that someone had "one-upped" them. So the later model C and D military flyers had large forward finlets, which the Wrights called "blinkers" to offset the severe adverse yaw inherent with the design. Not to say the Curtiss machines had no adverse yaw but the Wrights design was clearly up against a formidable shortcoming.

Yeah, but HIS had a telephone in it

 

[Van Johnston]

Always good be specific irregardless of the task at hand.

Well played sir.

 

[FastEddieB]

Anyone familiar with getting the plane "on step" so it cruises faster?

Look at this power required curve:

Any given power setting can result in two different airspeed. It's most likely to be an issue at low power settings.

Power back too soon, and you may be laboring on the back side of the power curve, whereas that same power setting could be providing a higher speed if the plane was allowed to accelerate to it.

I think that's where the illusion of a "step" comes from.

 

[Henning]

Look at this power required curve:

Any given power setting can result in two different airspeed. It's most likely to be an issue at low power settings.

Power back too soon, and you may be laboring on the back side of the power curve, whereas that same power setting could be providing a higher speed if the plane was allowed to accelerate to it.

I think that's where the illusion of a "step" comes from.

No, you have never heard the legend of "The Step" as it is properly told. It is a mythical, magical, maneuver employed transitioning from climb to cruise, that will get between 5 and 15 kts higher cruise speed at the same settings.

 

[MAKG1]

No, you have never heard the legend of "The Step" as it is properly told. It is a mythical, magical, maneuver employed transitioning from climb to cruise, that will get between 5 and 15 kts higher cruise speed at the same settings.

Is that the one where you supposedly overshoot your altitude, then descend into it, magically getting more cruise speed?

 

[flyingcheesehead]

It all wants to climb, it just wants to climb less on the tips, and that also helps the roll stability and ride in turbulent and gusty conditions.

Not to mention, the lower moment of lift around the longitudinal axis means less wing structure required.

 

[Henning]

Is that the one where you supposedly overshoot your altitude, then descend into it, magically getting more cruise speed?

That would be the one.

 

[Henning]

If you look at air vs water as fluids, and think about a boat "getting on the step" you see it is climbing on a pressure wave. It's the same thing an airplane does, it rides a pressure wave of air. As soon as the plane is airborne, it is fully, "on the step" at that point in time. You can alter how efficiently you are riding the step by altering CG, but not by method of attaining cruise speed. If you overshoot and drop in with high power, you will end up decelerating into your terminal cruise speed sooner than if you start trimming yourself up from beneath, however your terminal cruise speed will end up the same in very short order.

 

[N801BH]

If you look at air vs water as fluids, and think about a boat "getting on the step" you see it is climbing on a pressure wave. It's the same thing an airplane does, it rides a pressure wave of air. As soon as the plane is airborne, it is fully, "on the step" at that point in time. You can alter how efficiently you are riding the step by altering CG, but not by method of attaining cruise speed. If you overshoot and drop in with high power, you will end up decelerating into your terminal cruise speed sooner than if you start trimming yourself up from beneath, however your terminal cruise speed will end up the same in very short order.

Great discription....

 

[Stevel]

If you look at air vs water as fluids, and think about a boat "getting on the step" you see it is climbing on a pressure wave. It's the same thing an airplane does, it rides a pressure wave of air. As soon as the plane is airborne, it is fully, "on the step" at that point in time. You can alter how efficiently you are riding the step by altering CG, but not by method of attaining cruise speed. If you overshoot and drop in with high power, you will end up decelerating into your terminal cruise speed sooner than if you start trimming yourself up from beneath, however your terminal cruise speed will end up the same in very short order.

Damn! Some smartass has to go and get all technical, accurate, and all that. You are ruining it for all of us. Now I'll never get my ultralight(ish) plane much above Mach .1 in level flight.

 

[Stewartb]

If you look at air vs water as fluids, and think about a boat "getting on the step" you see it is climbing on a pressure wave. It's the same thing an airplane does, it rides a pressure wave of air. As soon as the plane is airborne, it is fully, "on the step" at that point in time. You can alter how efficiently you are riding the step by altering CG, but not by method of attaining cruise speed. If you overshoot and drop in with high power, you will end up decelerating into your terminal cruise speed sooner than if you start trimming yourself up from beneath, however your terminal cruise speed will end up the same in very short order.

A pressure wave? Do you not believe in lift?

 

[N801BH]

A pressure wave? Do you not believe in lift?

Lift exists for sure.... But.. Deflection is a real effect too...

 

[Henning]

A pressure wave? Do you not believe in lift?

No! And I'll tell you why.... I had an instructor, Jack Thelander, chief aerodynamic engineer for Douglas. "Everything you have learned about aerodynamics to date is incorrect." Was his introduction to aerodynamics.

However, he proved his position with a physical experiment involving flying over a very sensitive recording barometer. "Bernoulli is just an observation of Newton." Flying over the barometer and applying the area of the barometer pick up to the area of the wing and applying the various corrections came up with the weight of the plane and us.

I don't argue it though, this is one doctorate bearing guys get in fights about, I just stand back. I don't care exactly how it flies, just that it does.

 

[Pilawt]

IIRC, the hershy wing Cherokees have little or no washout.

They had some washout -- not a heckuva lot, but some. I spent enough time polishing the wings of mine to notice stuff like that.