Yes, the drag of the aileron, even in a 170, exists. More at way too much speed. Almost none at the speed we should be. From a teaching point of view, it could shift orientation just a bit. I just don't think we should go there.

What we believe, our orientation, greatly influences our decisions and actions. A pilot might just be tired or distracted, or he may believe he can control longitudinal axis alignment with the control wheel alone or with coordinated turns to realign.

A pilot might find the powerful and rapid change of longitudinal axis alignment using differential braking effective.

A pilot might find reactive rudder movement keep longitudinal axis alignment. effectively.

A pilot might find continuous dynamic proactive rudder movement keep longitudinal axis alignment effectively.

Which pilot will most likely be moving the rudders continuously? Which pilot will most believe rudder is primary in longitudinal axis alignment?

I’m with Contact. I think when you “get it” you are constantly making very small corrections very early. I think the brain just gets better at anticipating the way the aircraft is going to go and makes an early correction. To an observer it’s hard to see the reason the pilot tapped the rudder. He anticipated the need.

How you teach this I have no idea, I really think that you have to just get the mileage.

I am very big on slow landings or at least touchdowns. Energy increases with the square of speed more energy = more damage. Sportsman has really helped this for me.

Thanks daedaluscan,

Actually, it is much easier to teach dynamic proactive rudder movement than static reactive rudder jab. The latter requires the instructor to ride the controls a bit to be able to jab in time. With dynamic proactive, we have to stay off the controls and wait for enough error that we jump in. Yelling a lot is part of the technique. Yes, this can be harder on the airplane. It is the only way for the student to learn quickly and have greater confidence, however. Also using older, simpler, cheaper airplanes helps reduce worry. Instructor tension transfers to the student and affects both quality and quickness of training.

Contact, I have learned a lot from your book, and from your many posts here on BCP. But I have to admit that the whole "proactive control movement" to "bracket the runway" leaves me stone cold. It strikes me as aerodynamically inefficient, and has to be inherently destabilizing. Taken literally, and taken far enough in practice, it seems like it could be the final aerodynamic straw that initiates a ground loop, just as in a helicopter, rapid proactive movement of the cyclic can be the final aerodynamic straw that leads to dynamic rollover during a slope landing. And while I recognize there are many differences between flying helicopters and flying fixed-wing aircraft, the laws of physics still apply to both.

When I was instructing in helicopters, many of my students over-controlled both the cyclic stick and the anti-torque pedals – often extensively. We could not move on to tactical training with (which involved slope landings on unprepared surfaces) until this "over-controlling" tendency was eradicated. Those tendencies were only magnified when flying with Night Vision Goggles, which also raised the bar for difficulty on slope landings. I couldn't pass them as "mission qualified" until they could accomplish all the basic maneuvers during day, night, and NVG flight.

Because this was so difficult a habit to break, I used to demonstrate the inefficiency of this "proactive control movement" technique by establishing a stabilized 1-foot hover, then "walking" the anti-torque pedals back and forth like the student was doing. Every time (100%) the aircraft would settle and touch down, remaining on the ground (though "writhing" slightly) while the "proactive" pedal movement was continued. But as soon as we stopped walking the pedals back-and-forth, the aircraft would lift back off and return to a stabilized 1-foot hover.

Then I would repeat the demonstration, but this time "rowing" the cyclic stick quickly back and forth, forward and back. Again, every time (100%) the aircraft would settle to the ground (though generally this technique resulted in a somewhat "bumpier" touchdown). And again, as soon as we stopped "proactively" moving the controls, the aircraft would lift back off and reestablish the 1-foot hover.

I would then demonstrate to them that an entire takeoff, traffic pattern, and landing could be done without moving the cyclic stick more than an inch in any direction. I would establish a standard 3-foot hover, have them make a circle around the cyclic stick with their two hands, and fly the entire pattern without touching their hands with the cyclic. Had I been less scrupulous, I would have placed wagers with them, because to a man, they believed it would be impossible. Yet within a couple of hours, they were duplicating the feat themselves! For students who had been literally beating my legs with the cyclic stick, it was an eye-opener, for sure!

Jim, I know you flew helicopters as well, and I suspect you're very familiar with what I described above. It just seems to me that in much the same way, "wagging" the tail on landing (proactive rudder movement) is aerodynamically inefficient because you're constantly creating "upsets" that have to be cancelled by the counter-movement. That is simply inefficient, and means that some portion of the control input is completely wasted. Thus you have less true "reserve" control, because you've wasted some of it countering the "dynamic" disturbance – which you just created.

The same aerodynamic inefficiency would occur from "rocking the wings" (proactive aileron movement) or from creating "pilot induced oscillations" (proactive elevator movement). It just makes zero sense to me to give up aerodynamic efficiency in all three axis while simultaneously demanding more and more control movement to return the aircraft to a "neutral" (stabilized) condition.

Is it harder to train pilots to be able to make "reactive" control movements? To recognize the smallest change in sight picture and react quickly enough to apply control pressures to counter those movements? I will grant that those statements are probably true. But I would also postulate that just as new helicopter pilots at some point "find the hover button", new tailwheel pilots will find the "centerline" button as well. But not if they are taught that it is "correct" to constantly over-control the rudder, ailerons, and elevator through "proactive movement". Those pilots will always be "out of control" except for the brief micro-seconds when their controls pass through the "neutral" position for their particular aerodynamic situation.

Jim, I respect your experience and background immensely, and I truly mean no disrespect. I will readily acknowledge that my experience is minuscule compared to yours. I truly would like to hear your thoughts on the above, and how you reconcile your "dynamic proactive control movement" philosophy with all of this. Thanks!

JP256 wrote:Contact, I have learned a lot from your book, and from your many posts here on BCP. But I have to admit that the whole "proactive control movement" to "bracket the runway" leaves me stone cold. It strikes me as aerodynamically inefficient, and has to be inherently destabilizing. Taken literally, and taken far enough in practice, it seems like it could be the final aerodynamic straw that initiates a ground loop, just as in a helicopter, rapid proactive movement of the cyclic can be the final aerodynamic straw that leads to dynamic rollover during a slope landing. And while I recognize there are many differences between flying helicopters and flying fixed-wing aircraft, the laws of physics still apply to both.

When I was instructing in helicopters, many of my students over-controlled both the cyclic stick and the anti-torque pedals – often extensively. We could not move on to tactical training with (which involved slope landings on unprepared surfaces) until this "over-controlling" tendency was eradicated. Those tendencies were only magnified when flying with Night Vision Goggles, which also raised the bar for difficulty on slope landings. I couldn't pass them as "mission qualified" until they could accomplish all the basic maneuvers during day, night, and NVG flight.

Because this was so difficult a habit to break, I used to demonstrate the inefficiency of this "proactive control movement" technique by establishing a stabilized 1-foot hover, then "walking" the anti-torque pedals back and forth like the student was doing. Every time (100%) the aircraft would settle and touch down, remaining on the ground (though "writhing" slightly) while the "proactive" pedal movement was continued. But as soon as we stopped walking the pedals back-and-forth, the aircraft would lift back off and return to a stabilized 1-foot hover.

Then I would repeat the demonstration, but this time "rowing" the cyclic stick quickly back and forth, forward and back. Again, every time (100%) the aircraft would settle to the ground (though generally this technique resulted in a somewhat "bumpier" touchdown). And again, as soon as we stopped "proactively" moving the controls, the aircraft would lift back off and reestablish the 1-foot hover.

I would then demonstrate to them that an entire takeoff, traffic pattern, and landing could be done without moving the cyclic stick more than an inch in any direction. I would establish a standard 3-foot hover, have them make a circle around the cyclic stick with their two hands, and fly the entire pattern without touching their hands with the cyclic. Had I been less scrupulous, I would have placed wagers with them, because to a man, they believed it would be impossible. Yet within a couple of hours, they were duplicating the feat themselves! For students who had been literally beating my legs with the cyclic stick, it was an eye-opener, for sure!

Jim, I know you flew helicopters as well, and I suspect you're very familiar with what I described above. It just seems to me that in much the same way, "wagging" the tail on landing (proactive rudder movement) is aerodynamically inefficient because you're constantly creating "upsets" that have to be cancelled by the counter-movement. That is simply inefficient, and means that some portion of the control input is completely wasted. Thus you have less true "reserve" control, because you've wasted some of it countering the "dynamic" disturbance – which you just created.

The same aerodynamic inefficiency would occur from "rocking the wings" (proactive aileron movement) or from creating "pilot induced oscillations" (proactive elevator movement). It just makes zero sense to me to give up aerodynamic efficiency in all three axis while simultaneously demanding more and more control movement to return the aircraft to a "neutral" (stabilized) condition.

Is it harder to train pilots to be able to make "reactive" control movements? To recognize the smallest change in sight picture and react quickly enough to apply control pressures to counter those movements? I will grant that those statements are probably true. But I would also postulate that just as new helicopter pilots at some point "find the hover button", new tailwheel pilots will find the "centerline" button as well. But not if they are taught that it is "correct" to constantly over-control the rudder, ailerons, and elevator through "proactive movement". Those pilots will always be "out of control" except for the brief micro-seconds when their controls pass through the "neutral" position for their particular aerodynamic situation.

Jim, I respect your experience and background immensely, and I truly mean no disrespect. I will readily acknowledge that my experience is minuscule compared to yours. I truly would like to hear your thoughts on the above, and how you reconcile your "dynamic proactive control movement" philosophy with all of this. Thanks!

Very well said. I couldn't agree more.

MTV

Jim,

Thanks for your support elsewhere and for your and MTV'S criticism of dynamic proactive rudder and elevator control movement. You, MTV, Cary, and others here are better instructors than I am. You have accomplished the mission and helped many through the program. I have always been a pain in the neck and as Richard Castle, who wrote the forward to "Contact Flying," said to me, "Jim, you are a renegade. You have always been off the reservation."

What I have done, both military and civilian, is pick up on good technique both from others and from experience. You are right about the laws of physics. Not just helicopters, but many machines have similar characteristics. There are also similar interface with human aspects. Dynamic proactive control is one of those.

While there are similarities between anti-torque longitudinal axis alignment and rudder longitudinal axis alignment, there is an important difference. The helicopter is powered up fully before any control input. The tw airplane needs gross rudder movement when airspeed is slow and finer rudder movement when fast. In either case gross or fine anti-torque or control movement will work. Efficiency, no. And while helicopters will demand full attention throughout all operations, airplanes can put a pilot to sleep; especially his feet.

You are right about slope operations. Finding the ground loop tip point in a Cub can be embarrassing and damage equipment. Tipping the tip path plane can be fatal. Parts generally fly outward, but can get inside the helicopter as well.

Exaggeration is not a popular instructional technique, but it works. If a student finds out that gross control movement, say rudder to the stops dynamically and proactively during slow taxi, works, he will not fear bad things happen and fear others are watching. Dynamic proactive rudder movement needs to be finer, for efficiency, when fast on takeoff, but gross will work. The beauty of dynamic proactive control movement, both rudder and elevator, is that the student needn't fear too much or too little. It allows for a great deal more discovery learning. It allows the student to gain experience and confidence quickly.

Yes, the book supports static reactive control movement. Theoretically, it is more efficient. I preach efficiency on takeoff, but I will sacrifice some to stay ahead of the airplane and not wait until it decides to err. On landing, 40 degree flaps, slats, dirtiness, or any other type of inefficiency is actually desirable. The design of the airplane is to fly, and here is one place we don't want that.

People are going to do what they do, especially old ones. As instructors, we have to really think hard about our orientation and how we pass that orientation on. Do we want their feet to move? Do we want them to wait and react. Both work and the later is theoretically more efficient. What is the advantage of always being ahead of the airplane. What is the advantage of putting the longitudinal axis, between our legs, just a bit left of centerline followed immediately by just a bit right of centerline, etc. continuously?

My students don't believe an airplane will necessarily climb and let the nose go down a bit in a turn. In the pattern. Is that safe?

Think about what you teach in terms of perpetual student (later pilot) orientation.

I agree with what Jim Parker wrote above, excellent Jim!

Kurt

Jim Parker mentioned a maneuver that may shed some light on the ground loop problem and longitudinal axis alignment control techniques. Setting a helicopter completely down on a slope, rather than hover with just the uphill skid touching, is much more dangerous. There is a maximum grade of slope possible. If we reduce collective into too great of slope, the tip path plane (big round wing) can reach a tip point that guarantees the helicopter will crash. Past that point, either more down collective or pulling up increasing thrust/lift will put the down side of the tip path plane into the surface.

Like Jim said, dynamic proactive control doesn't seem to make sense here. We certainly don't want to rock around on the down slope skid. What we are doing is using fine motor control down on the collective while keeping the longitudinal axis parallel to the slope with anti-torque pedals and the tip path plane level with cyclic. Of course reducing collective will cause the tip path plane to bank down slope. This is because the one skid is fixed on the upslope. It is like a side slip in a crosswind.

The controls are not fixed here. The collective is being moved down a little, wait, not so fast. The right hand on the cyclic is moving, finely, but moving, constantly moving. Same with the anti-torque pedals. What cannot be allowed to go beyond the tip point is the amount we allow the bank to increase.

So as we tip toward the point of no return, we use creeping collective much like creeping fire to bring our artillery fire closer to our position by sound in the jungle. Creeping fire is like static reactive control movement. Bracketing is dynamic proactive. We definitely don't want to bracket the tip point and crash.

Landing a tw airplane is far less tense. The ground loop tip point is unidirectional. The tip point is not as deadly. Dynamic search for straight makes a lot of sense. Creeping fire makes less sense. We can use dynamic proactive rudder movement to bracket the centerline or we can use creeping fire to walk just enough in. With lots of practice, pilots can learn the just enough reactive rudder movement for just so out of longitudinal alignment. I found dynamic proactive to be much easier for the student or even experienced pilot to learn. I found dynamic proactive rudder movement to bracket the centerline to be much more likely to keep the pilots feet in the game and therefore more likely to prevent ground loop.

contactflying wrote:Jim,

Thanks for your support elsewhere and for your and MTV'S criticism of dynamic proactive rudder and elevator control movement. You, MTV, Cary, and others here are better instructors than I am. You have accomplished the mission and helped many through the program. I have always been a pain in the neck and as Richard Castle, who wrote the forward to "Contact Flying," said to me, "Jim, you are a renegade. You have always been off the reservation."

What I have done, both military and civilian, is pick up on good technique both from others and from experience. You are right about the laws of physics. Not just helicopters, but many machines have similar characteristics. There are also similar interface with human aspects. Dynamic proactive control is one of those.

While there are similarities between anti-torque longitudinal axis alignment and rudder longitudinal axis alignment, there is an important difference. The helicopter is powered up fully before any control input. The tw airplane needs gross rudder movement when airspeed is slow and finer rudder movement when fast. In either case gross or fine anti-torque or control movement will work. Efficiency, no. And while helicopters will demand full attention throughout all operations, airplanes can put a pilot to sleep; especially his feet.

You are right about slope operations. Finding the ground loop tip point in a Cub can be embarrassing and damage equipment. Tipping the tip path plane can be fatal. Parts generally fly outward, but can get inside the helicopter as well.

Exaggeration is not a popular instructional technique, but it works. If a student finds out that gross control movement, say rudder to the stops dynamically and proactively during slow taxi, works, he will not fear bad things happen and fear others are watching. Dynamic proactive rudder movement needs to be finer, for efficiency, when fast on takeoff, but gross will work. The beauty of dynamic proactive control movement, both rudder and elevator, is that the student needn't fear too much or too little. It allows for a great deal more discovery learning. It allows the student to gain experience and confidence quickly.

Yes, the book supports static reactive control movement. Theoretically, it is more efficient. I preach efficiency on takeoff, but I will sacrifice some to stay ahead of the airplane and not wait until it decides to err. On landing, 40 degree flaps, slats, dirtiness, or any other type of inefficiency is actually desirable. The design of the airplane is to fly, and here is one place we don't want that.

People are going to do what they do, especially old ones. As instructors, we have to really think hard about our orientation and how we pass that orientation on. Do we want their feet to move? Do we want them to wait and react. Both work and the later is theoretically more efficient. What is the advantage of always being ahead of the airplane. What is the advantage of putting the longitudinal axis, between our legs, just a bit left of centerline followed immediately by just a bit right of centerline, etc. continuously?

My students don't believe an airplane will necessarily climb and let the nose go down a bit in a turn. In the pattern. Is that safe?

Think about what you teach in terms of perpetual student (later pilot) orientation.

And maybe I'm beginning to gain a tiny bit of understanding here... Is your "dynamic proactive movement" as more of a "phase" you take the student through, rather than something to be carried on all the time? If so, that makes a lot more sense.

In the early stages, when my helicopter students were darn near panic-stricken at the "over-reaction" of the aircraft to their control movements, when they first began to try to hover, I would sometimes do something similar. Only in my case, I would establish a stabilized 3-foot hover, then begin "stirring" the cyclic stick around in ever-widening circles, all while maintaining the stabilized 3-foot hover (which required a bit more collective and some additional anti-torque, but Contact knows that). The point was to demonstrate that even large control movements – by themselves – do nothing if you immediately counter them. In this demo, the helicopter might eventually begin to oscillate slowly, as though it were a kid's toy top beginning to wobble a bit as it spun, but it would remain over the starting spot. I would have them join me on the controls and re-create the exercise with them "flying" and me backing them up, and eventually just have them doing it on their own. This was always eye-opening for the students!

My goal was for them to understand that just moving the controls around was not the way to fly the helicopter. First you had to sort of "establish a zen-state" where everything was as calm as it can possibly in a helicopter (which is an oxymoron in and of itself), then use slight pressure on the controls to make it do what you want it to. As with finding the "hover button", some took longer than others, but went on to become pretty decent aviators.

Yes, Jim. You got me.

Another concern, and a big one, is concurrent and recurrent training. As you have figured out by now, those concepts are not as welcome in the civilian world. What do we do with those who have not figured out the itsy bitsy dynamic proactive hover button?

When I did flight reviews, I promised to just sit and watch a couple of circuits. I offered, with their permission, to show them a little different orientation (voice mostly with little demonstration.) If they were game, I briefed safe maneuvering flight techniques and then proceeded to thoroughly corrupt them. Most loved it and came bank for recurrent in two years.

It only works if we use Boyd's orientation in "Destruction and Creation." We have to get beyond the old, PTS indoctrinated orientation. Things like pressure on controls rather than movement. While true in some situations like basic instrument control, we want to destroy a bit (exaggerate) the hover button to build a proper orientation hover button. I have had quicker and more productive results demonstrating baby steps, gross control movement before fine control movement. These guys are pilots. We can get most everything across by talking and what little demonstration is necessary need not look so professional. We want to excessively demonstrate the technique to separate new concepts from old.

Pilots talk about using their feet, but most don't want the slight wiggle that would be there. Most don't believe rudder leads aileron in a coordinated turn, especially at slower airspeed. Pilots believe the airplane will climb if they pull back on the stick. Pilots believe there are laws demanding level turns and only left turns in a pattern that must be 1,000' at MO9 where every local pilot is going to be at 200' including students.

Our government does a good job keeping most on the procedural track. We are good soldiers and need teach respect for the government. Safe maneuvering flight techniques are not illegal, just different. All of my techniques existed prior to instrument integration and basic instrument practical test standards. My stuff is not for everyone. The government also realizes it has some loss of control in a contact environment problems.

Hang in there, Jim. You're doing a good job.

Jim

A lot more engineering brain energy went into the simple but safe flying behavior of the two and four place trainers we fly. Much less engineering brain energy went into the ground handling behavior, especially of tw airplanes.

From the pilots point of view, he can generally trust the airplane in the air. He can relax when high. If the tactical situation causes him to come unglued, he can let go and the airplane will generally help him. At least it won't stall. The tw airplane will not help him on the ground. The safe solution is to avoid ground roll as much as possible by getting into low ground effect quickly and by slowing down to near stall speed before entering ground effect on landing. There is no more bad flight behavior, in low ground effect, on landing than on takeoff. The problem is we don't control when it stops flying and starts rolling. And it is much more important, while rolling, to stay ahead of the tw airplane. And the most dangerous time, damage wise, is rolling at high speed.

Meybe we should look, in slow motion, at how best to stay ahead of the airplane while rolling on the ground. I think we all realize that the rudder is what best controls longitudinal axis alignment in the air or on the ground. It gets more prop blast than aileron, it works symmetrically without adverse yaw, it attaches to the tailwheel, it doesn't bank the wing down toward the pavement, is a primary control, it pulls aileron in a coordinated turn, it is just a real good go to control. When slow and the tail is down, we have fair tailwheel control. When fast and the tail is up, we have more relative wind to increase rudder effectiveness.

So with the tail down or up, how can we best stay ahead of the longitudinal axis alignment of a fuselage with the center of gravity behind us and the gear? How do we best keep the centerline between our legs and the tail behind us? How do we best stay ahead of the airplane which will try to turn left or right, it's choice, and swing the tail around?

Method one: Static Reactive Rudder Pressure: We remain static on the rudder pedals until the airplane makes its move and then react by putting just enough pressure on the rudder away from that longitudinal axis movement away from the centerline. If this very specific pressure is successful, we now have the longitudinal axis parallel to the centerline again. We can either adjust back to the centerline or again wait for the airplane to make its move. Etc.

Method two: Dynamic Proactive Rudder Movement: We move the right rudder pedal to direct the longitudinal axis just slightly right of centerline. No reaction, we just do it. Before the airplane has time to leave the centerline, we move the left rudder pedal to direct the longitudinal axis just left of centerline. Etc.

In method one, the airplane moves and we react. In method two, we move the rudder pedals dynamically and proactively continuously and quickly. We control the movement and we control the timing. We push the nose around; we don't let the nose push us around.

MTV

akschu wrote: My favorite ground loop video: ....Pilot basically just quits flying....

Here's a video of a Lockheed model 12 groundlooping in Belgium.
A guy I know hel;ped fly it over to Europe not long before this incident.
The fun (not) starts at about 1:40.

https://www.documentingreality.com/foru ... ng-187922/

hotrod180 wrote:

akschu wrote: My favorite ground loop video: ....Pilot basically just quits flying....

Here's a video of a Lockheed model 12 groundlooping in Belgium.
A guy I know hel;ped fly it over to Europe not long before this incident.
The fun (not) starts at about 1:40.

https://www.documentingreality.com/foru ... ng-187922/

Appeared fixated on parking there without taxiing back - he had put full left rudder in and held it there.

Coordinated turns on short final, to deal with gusts, indicate he may have been driving with the control wheel rather than directing the longitudinal axis with rudder movement. Seemed to have the wobbly touchdown under control, but maybe not.

When I was putting Ag students in the single seat Pawnee for their first circuits, I used an observation point much closer to the runway than the camera in the 170 or the Super 18 video. The main two things I was looking for were tail wagging rather than wing wobbling and maintenance of the apparent brisk walk rate of closure all the way down.

If the tail was wagging, indicating dynamic proactive rudder movement, on short final, that walking the rudder down the centerline would likely continue. If he didn't allow the apparent brisk walk rate of closure all airplanes have way out to speed up on short final, he was going to touch down slowly and softly on the numbers.

I'm not a twin driver and can't fuss with the speed of the Super 18, but both airplanes had wing wobbling issues and both allowed the apparent brisk walk rate of closure to speed up on short final. That is, neither slowed up on short final.

Does either problem guarantee a ground loop? No, but using the rudder rather than coordinated turns for directional control helps prevent miss-alignment and higher speed ground loops are more damaging.

The only way coordinated turns could equal dynamic proactive rudder for longitudinal axis alignment is if we executed Dutch Rolls down final, touchdown, and roll out. I think Brian, the tailwheel pilot guy, teaches that, but he is a show pilot. By the way, rudder pulls aileron in the Dutch Roll or any coordinated turn.

I just watched Trent Palmer's excellent U-tube video, "The Ground Loop Monster." He nails the common progression of a pilot from nose wheel to tailwheel training. The pilot has no concept of ground loop until the airplane introduces one and the instructor has to take over. Next time the airplane introduces one he reacts grossly and perhaps with brake. Finally he begins to anticipate the miss direction early and makes fine reactive corrections just back to center.

As I don't teach that way I don't know, but i think he finally uses fine dynamic proactive rudder movement just as JP256's students begin to find the hover button.

Finally, by teaching gross dynamic proactive rudder movement from day one through day 17,000 hours, I do teach what Trent is getting to: don't wait until the airplane does what it wants to do. Make the airplane do what you want it to do from the first instant. Thanks again, Trent.

So you are asking the airplane to missalign with the centerline or centerline extended? No sweat, GI. You are in control. Now ask it to misalign the same amount the other way. How can we say move your feet and not be asking for this very thing?

The fact that nose gear pilots tend to be slightly off the centerline extended and making coordinated turns to continuously realign cannot be blamed on the airplane designers. They improved the ground movement safety of the airplane by putting the center of gravity in front of the mains with the nose gear. Ground dynamic proactive rudder movement works equally well to stay on the centerline extended, keep the wing level in rough air, direct the airplane to a distant target, shoot rockets, keep the localizer centered, and spray crops no matter whether the center of gravity is behind or in front of the gear. The design of the airplane is to fly. And it does that very precisely using rudder only to keep the wing level and direct the airplane to target.

mtv wrote:

JP256 wrote:Contact, I have learned a lot from your book, and from your many posts here on BCP. But I have to admit that the whole "proactive control movement" to "bracket the runway" leaves me stone cold. It strikes me as aerodynamically inefficient, and has to be inherently destabilizing. Taken literally, and taken far enough in practice, it seems like it could be the final aerodynamic straw that initiates a ground loop, just as in a helicopter, rapid proactive movement of the cyclic can be the final aerodynamic straw that leads to dynamic rollover during a slope landing. And while I recognize there are many differences between flying helicopters and flying fixed-wing aircraft, the laws of physics still apply to both.

When I was instructing in helicopters, many of my students over-controlled both the cyclic stick and the anti-torque pedals – often extensively. We could not move on to tactical training with (which involved slope landings on unprepared surfaces) until this "over-controlling" tendency was eradicated. Those tendencies were only magnified when flying with Night Vision Goggles, which also raised the bar for difficulty on slope landings. I couldn't pass them as "mission qualified" until they could accomplish all the basic maneuvers during day, night, and NVG flight.

Because this was so difficult a habit to break, I used to demonstrate the inefficiency of this "proactive control movement" technique by establishing a stabilized 1-foot hover, then "walking" the anti-torque pedals back and forth like the student was doing. Every time (100%) the aircraft would settle and touch down, remaining on the ground (though "writhing" slightly) while the "proactive" pedal movement was continued. But as soon as we stopped walking the pedals back-and-forth, the aircraft would lift back off and return to a stabilized 1-foot hover.

Then I would repeat the demonstration, but this time "rowing" the cyclic stick quickly back and forth, forward and back. Again, every time (100%) the aircraft would settle to the ground (though generally this technique resulted in a somewhat "bumpier" touchdown). And again, as soon as we stopped "proactively" moving the controls, the aircraft would lift back off and reestablish the 1-foot hover.

I would then demonstrate to them that an entire takeoff, traffic pattern, and landing could be done without moving the cyclic stick more than an inch in any direction. I would establish a standard 3-foot hover, have them make a circle around the cyclic stick with their two hands, and fly the entire pattern without touching their hands with the cyclic. Had I been less scrupulous, I would have placed wagers with them, because to a man, they believed it would be impossible. Yet within a couple of hours, they were duplicating the feat themselves! For students who had been literally beating my legs with the cyclic stick, it was an eye-opener, for sure!

Jim, I know you flew helicopters as well, and I suspect you're very familiar with what I described above. It just seems to me that in much the same way, "wagging" the tail on landing (proactive rudder movement) is aerodynamically inefficient because you're constantly creating "upsets" that have to be cancelled by the counter-movement. That is simply inefficient, and means that some portion of the control input is completely wasted. Thus you have less true "reserve" control, because you've wasted some of it countering the "dynamic" disturbance – which you just created.

The same aerodynamic inefficiency would occur from "rocking the wings" (proactive aileron movement) or from creating "pilot induced oscillations" (proactive elevator movement). It just makes zero sense to me to give up aerodynamic efficiency in all three axis while simultaneously demanding more and more control movement to return the aircraft to a "neutral" (stabilized) condition.

Is it harder to train pilots to be able to make "reactive" control movements? To recognize the smallest change in sight picture and react quickly enough to apply control pressures to counter those movements? I will grant that those statements are probably true. But I would also postulate that just as new helicopter pilots at some point "find the hover button", new tailwheel pilots will find the "centerline" button as well. But not if they are taught that it is "correct" to constantly over-control the rudder, ailerons, and elevator through "proactive movement". Those pilots will always be "out of control" except for the brief micro-seconds when their controls pass through the "neutral" position for their particular aerodynamic situation.

Jim, I respect your experience and background immensely, and I truly mean no disrespect. I will readily acknowledge that my experience is minuscule compared to yours. I truly would like to hear your thoughts on the above, and how you reconcile your "dynamic proactive control movement" philosophy with all of this. Thanks!

Very well said. I couldn't agree more.

MTV

+1