On the step...

timwinters

timwinters

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timwinters said:
...didn't Barry Schiff actually disprove his own premise in this article?

https://www.aopa.org/news-and-media/all-news/2016/may/pilot/proficientpilot

i.e. rather than disprove that one can get "on step" didn't he simply prove that there's more than one way to achieve it?

This was in the May issue. I haven't scoured June or July to see if it elicited mail.
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"On the step"
is a phrase used by older pilots that describes a method of finding "best power range" using the VSI and mixture. once that is reached it is just a matter of finding LOP slightly leaner.
 
3 in the green said:
Hmmm, I was brought up to understand "on the step" as something else entirely. :D
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You and a lot of others.
Read every thing you can about how Lindbergh tough the military how to get maximum endurance from the large radial engines.
 
I've heard about it and seen it "demonstrated," but I'm just not a believer.
 
I read that article. Barry is definitely not talking about LOP:

"The theory goes like this: During climb, the pilot climbs a few hundred feet above the desired cruise altitude. He then enters a shallow dive to return to cruise altitude. According to proponents, this results in a slightly greater and sustainable cruise airspeed than otherwise would be possible. This is what they call “flying on the step.”

He does go on to talk about the proper way to level off and trim for cruise.
 
He had an article 20 years ago on it too:

1996
https://www.aopa.org/news-and-media/all-news/1996/march/pilot/proficient-pilot-(3)

a more recent AOPA video, Filucci/Hirschman... at the bottom

I am thinking that a 'step' can only occur at a fluid interface where there is significant differences in their μ (cF) ....ie water and air, with a seaplane.
The other thing that leads me to believe it does not exist is that airliners, who are all about chasing the knot, would be all over this like a nasty rash if it were true.

Airliners.net 12 years ago
http://www.airliners.net/forum/viewtopic.php?t=739005

Pprune:
http://www.pprune.org/archive/index.php/t-9556.html

GAN?
http://generalaviationnews.com/2015/09/15/no-step/

OWT thread this year (post 10 is where it seems to start)
https://www.pilotsofamerica.com/community/threads/owt-compilation.94532/

Mainly Henning's thoughts on it (post 51ish)
https://www.pilotsofamerica.com/com...owards-the-wingtips.83939/page-2#post-1834395

 
On the step is a crock. Literally - Flying magazine wore it out a long time ago.
 
On the step, or, how best to achieve cruise speed.
Most level off ant altitude and immediately set cruise power. The plane slowly accelerates from climb speed to cruise speed and you are constantly adjusting trim until stable cruise is achieved.

Some proponents say to climb above your cruise altitude and dive down to it while adjusting cruise power setting. Achieving stable cruise speed faster while your speed slows from the dive. Essentially achieving stable cruise slowing down rather than accelerating.

Others say to level off at altitude and leave climb power set until reaching cruise speed and then set cruise power and trim.

No matter the technique, it all results in the same cruise speed for the set cruise power.

It was all covered in one of the aviation mags a few months ago.
 
BillTIZ said:
. . .how best to achieve cruise speed.

. . . level off at altitude and leave climb power set until reaching cruise speed and then set cruise power and trim.
Click to expand...

This works well for me. I'll get on the step when I start working on my SES license.
 
Let'sgoflying! said:
He had an article 20 years ago on it too:
Click to expand...

Don't take me wrong, I'm not a believer of "on step" either. I just think Berry's article was very poorly written and, as such, he does more to perpetuate the debate than settle it.

He says that if you reduce power too soon after getting to your cruise altitude then "In a sense, the airplane is established in a subtle form of mushing flight."

But, if you leave full power in for a few minutes once you get to cruise altitude, then your plane accelerates beyond this "mushing flight" and achieves the same airspeed as it would have had you climbed an additional 300' and dove back down to cruise altitude.

Didn't you just put your plane "on step" by leaving full power in? Didn't you fail to get "on step" by retarding the throttle too quickly and remaining in "mushing flight" in the first example?

I'm not saying anything he wrote is true. I'm just arguing that because of how he wrote it, he did more to perpetuate the myth than dispel it.

(The important information that he failed to include, IMO, is whether the "mushing flight" was a permanent state or whether the plane gradually accelerated out of it. If the former then he inadvertently "proved" that on step exists.)
 
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The main point I've always take away from these articles is that there is no magic wave of air under the plane which makes it go faster. This can happen in a boat, but in an airplane we are dealing with one medium and to reach full speed we just call it accelerating.
 
I can see some validity to "flying" on the step. I fly a Seawind 3000 very regularly and it's not tolerant of changes in pitch during cruise. For example, if you stray a hundred or more feet below your altitude, the trim input or yoke input to get your altitude back scrubs off a considerable amount of speed you just worked so hard to get. I have a theory that it's because you're exposing quite a bit more surface area on the hull to the relative wind with the increased AOA to get your altitude back. Any thoughts? Like I said, just a theory. Pic very related

6AXr4VP.jpg
 
The extra drag will make a transient you have to overcome once back on altitude. It might be rather slow. The "step" as described is steady state; it will persist forever.
 
Not sure where it started but "Step" is poor terminology. On a seaplane or floatplane hull there is a step and when you're on it the whole back third of the float or hull is no longer dragging in the water. In order to be on it you have to, through forward motion, be displacing enough water (and air under the wings) to support the proportion of the aircraft's weight that has been relieved. How does this relate to flying through the air at cruise speed? It don't.

So whatever it is that they are talking about, whether it exists or not, they should call it something else.
 
So, the step is a farce however I have noticed a similar phenomenon when pulling my trailer on the highway. Goes like this:

When driving level, I get about 11mpg at 70mph. When climbing a hill, I get about 4.5mpg at same speed. Going down the other side of the hill, I get about 30mpg at same speed. Then, when level again, I get about 15mpg, level, at 70mph.

Can't explain that one.
 
Silvaire said:
Not sure where it started but "Step" is poor terminology. On a seaplane or floatplane hull there is a step and when you're on it the whole back third of the float or hull is no longer dragging in the water. In order to be on it you have to, through forward motion, be displacing enough water (and air under the wings) to support the proportion of the aircraft's weight that has been relieved. How does this relate to flying through the air at cruise speed? It don't.

So whatever it is that they are talking about, whether it exists or not, they should call it something else.
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When every one has their own opinion of what it is, how can you name it?
 
SkyHog said:
So, the step is a farce however I have noticed a similar phenomenon when pulling my trailer on the highway. Goes like this:

When driving level, I get about 11mpg at 70mph. When climbing a hill, I get about 4.5mpg at same speed. Going down the other side of the hill, I get about 30mpg at same speed. Then, when level again, I get about 15mpg, level, at 70mph.

Can't explain that one.
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Are you implying that "on the step" is a fuel economy thing?
 
Sundancer said:
On the step is a crock. Literally - Flying magazine wore it out a long time ago.
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When "Flying mag can't define it, how can they call it crock? I guess any thing they can't understand, must be a crock. ??
 
MAKG1 said:
The extra drag will make a transient you have to overcome once back on altitude. It might be rather slow. The "step" as described is steady state; it will persist forever.
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And it will when set up properly.
 
Silvaire said:
Not sure where it started but "Step" is poor terminology. On a seaplane or floatplane hull there is a step and when you're on it the whole back third of the float or hull is no longer dragging in the water. In order to be on it you have to, through forward motion, be displacing enough water (and air under the wings) to support the proportion of the aircraft's weight that has been relieved. How does this relate to flying through the air at cruise speed? It don't.

So whatever it is that they are talking about, whether it exists or not, they should call it something else.
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When taking off in a seaplane, once the step is reached you must reduce power to remain on the step or you'll lift off, to step taxi, you must set a reduce power to stay on the step.
But that isn't what we are referring to as "the step" when we are flying
 
Arbiter419 said:
I can see some validity to "flying" on the step. I fly a Seawind 3000 very regularly and it's not tolerant of changes in pitch during cruise. For example, if you stray a hundred or more feet below your altitude, the trim input or yoke input to get your altitude back scrubs off a considerable amount of speed you just worked so hard to get. I have a theory that it's because you're exposing quite a bit more surface area on the hull to the relative wind with the increased AOA to get your altitude back. Any thoughts? Like I said, just a theory. Pic very related

6AXr4VP.jpg
Click to expand...
Next you fly, try this:

After the climb, level off, set cruise power,allow every thing stabilize, then start to lean while watching the VSI. as you lean you will see the VSI show a climb as power and EGT is increased, trim back to level, you will see the climb converted to airspeed, lean some more, see the VSI show a climb, trim to level, repeat until the VSI shows a dive, at that point you have reached LOP, and are now regulating power by mixture. enriched the mixture will get the power and speed back, leaning more will slow you down, and run cooler.
 
"On the step" is real, but only in VERY limited circumstances.

WW2 heavy bombers would climb and get behind the power curve. If they just leveled off they stayed behind the power curve.

So they would climb above cruise altitude and dive through the power curve speed and go to normal cruise.

But, other than that VERY limited case, "On the Step" is complete nonsense.
 
Tom-D said:
When "Flying mag can't define it, how can they call it crock? I guess any thing they can't understand, must be a crock. ??
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Oh man, this was years, as in decades, ago - the myth was to climb a little above, then dive a bit to your altitude, and you'd get a magic airspeed improvement. They tested it out, and found it was not true. If I recall, there was a brief improvement, until forces came into balance, and maybe some laminar flow effects. But end of the day, the effect wasn't real.
 
The step comes from boating where you can generate a standing wave (the step) as part of your wake. By getting your boat up on the step you reduce the amount of hull and therefore reduce the amount of drag in the water, thus improving your speed. It transfer part of the hull from the dense medium of water to less dense/less draggy air.

The same mechanism is meaningless when you only have air. In the first place, how could your plane be "on" a standing wave? Second, how would that aerodynamically decrease drag? Air is air and all air creates basically the same drag. You can't move your plane from more draggy air to less draggy air.

The step is a standing wave generated by the movement of a boat through the water.
 
A "step" function is when there is an immediate (or very quick, think square wave) change. For instance a waterfall is a step fuction (they call that a hydraulic jump). So if there was some magical speed where the drag of the plane changed all of a sudden (like the speed of sound), then you might have a "step". But no, drag is a fairly smooth function.

Motor boats do climb out of their wave and rise up out of the water and get on the "step". So do seaplanes. And if you look at a seaplane there is indeed a physical step on the shape of the bottom of the float. The function of this step is to allow a high angle of attack initially so the plane can get enough lift to get on the front part of the floats. All very complex I know. Boats that climb up on their hydrofoils are getting "on the step" for sure. They have enough speed to get to a different mode of operation.
 
coloradobluesky said:
A "step" function is when there is an immediate (or very quick, think square wave) change. For instance a waterfall is a step fuction (they call that a hydraulic jump). So if there was some magical speed where the drag of the plane changed all of a sudden (like the speed of sound), then you might have a "step". But no, drag is a fairly smooth function.

Motor boats do climb out of their wave and rise up out of the water and get on the "step". So do seaplanes. And if you look at a seaplane there is indeed a physical step on the shape of the bottom of the float. The function of this step is to allow a high angle of attack initially so the plane can get enough lift to get on the front part of the floats. All very complex I know. Boats that climb up on their hydrofoils are getting "on the step" for sure. They have enough speed to get to a different mode of operation.
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By that definition, there IS a "step," but it's not what people have been thinking. The step is the critical angle of attack....and yes, it will work better from "above."
 
Tom-D said:
Are you implying that "on the step" is a fuel economy thing?
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Indirectly, yes. If it takes less power to maintain a given speed, or one can move faster given the same power, you could argue either side: it's either a fuel economy thing or a free speed thing.

In this scenario, it is fuel economy that provides evidence of something although I would argue that it is something other than "the step" as it is a farce

To be clear, the step I am referring to is not the water step for seaplanes but rather the concept that climbing above target altitude and descending back to target provides a benefit that simply climbing to target altitude does not.
 
The most elegant way to look at it is:
There is a step going from slow flight to normal flight.
There is a step when you retract the flaps.
But there is NO step when you go from dive, or normal descent to level cruise.
 
SkyHog said:
Indirectly, yes. If it takes less power to maintain a given speed, or one can move faster given the same power, you could argue either side: it's either a fuel economy thing or a free speed thing.
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Given that: when you get the best speed per gallons burned aren't you on the step? lean to best power, trim nose down to gain speed, =on the step.
When you dive to gain speed you gain momentum, trim to level, and then you must do some thing to maintain that speed when the momentum runs out.
 
Look at a Power Required curve and note at many power settings a plane can be flown in a steady state at either of two speeds.

At low altitudes, the difference in those speeds would make it pretty obvious a plane was stuck "behind the power curve", flying at 58 kts instead of 110 kts on the same power setting, let's say.

At 58 kts in the above example, power required is largely determined by induced drag; at 110 kts by parasitic drag.

But close to the absolute ceiling, those two speeds would be very close. There might be only a few knots difference. At the absolute ceiling they merge and there's only one speed that can maintain that altitude.

Hence the need to always be sure you're on the "front side", so to speak.

Best way to do this is to maintain climb power until established at the predicted cruise speed at your chosen cruise altitude. Only then power back. Nothing to be gained by climbing above your altitude and diving back down.
 
[QUOTE="Let'sgoflying!, post: 2107437, member: 25"}


The other thing that leads me to believe it does not exist is that airliners, who are all about chasing the knot, would be all over this like a nasty rash if it were true.

QUOTE]

I never did it when I flew at the airline but heard of at least one Capt that did it.
 
The first place I read about it was Ernest Gann's Fate Is the Hunter. I've read both of Barry Schiff's articles and this entire thread.

Interestingly enough, the flight instructor showed me how to "Get on the step" (his term) during my last IR lesson. It's the rather mundane climb above (in this case 100-200') our assigned altitude then accelerate down to the altitude. (This was in a Cessna 172C.) He did say "It gets us to cruise faster." He also uses the leave the power in until settled into cruise method.

Neither of these references made any mention of the mixture like Tom-D did above.

John
 
Tom-D said:
Given that: when you get the best speed per gallons burned aren't you on the step? lean to best power, trim nose down to gain speed, =on the step.
When you dive to gain speed you gain momentum, trim to level, and then you must do some thing to maintain that speed when the momentum runs out.
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Yep. And that is exactly why the step (as many people define it) is a farce. They believe that they are getting something (speed or econony) for nothing.
 
jsstevens said:
The first place I read about it was Ernest Gann's Fate Is the Hunter. I've read both of Barry Schiff's articles and this entire thread.

Interestingly enough, the flight instructor showed me how to "Get on the step" (his term) during my last IR lesson. It's the rather mundane climb above (in this case 100-200') our assigned altitude then accelerate down to the altitude. (This was in a Cessna 172C.) He did say "It gets us to cruise faster." He also uses the leave the power in until settled into cruise method.

Neither of these references made any mention of the mixture like Tom-D did above.

John
Click to expand...
Most CFIIs teach power + attitude = performance, which conflicts with that advice.

Blast 200 feet through your assigned altitude and you'll hear from ATC. Not a good habit AT ALL.

Instrument flight procedures are designed to keep you on the front side of the power curve at all times (at least until below DA/MDA), to the point where Vx climbs are discouraged. Vx is the boundary between front and back side in steady flight.
 
Let'sgoflying! said:
The other thing that leads me to believe it does not exist is that airliners, who are all about chasing the knot, would be all over this like a nasty rash if it were true.
Click to expand...

mscard88 said:
I never did it when I flew at the airline but heard of at least one Capt that did it.
Click to expand...

Yes, but a few pilots doing it is not like industry adoption, as I was discussing.
I think if this technique were to give them even a half a knot, airlines would have made it SOP long ago.
 
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