Aerodynamics from the book gives pilots an overview of what to expect from the controls, but experience hones in on what actually happens when we move the controls enough to see what's what. As Ronnie Westmoreland, my primary helicopter instructor in the TH-55 enjoyed yelling, "Move the controls; how else are you going to learn what they do?"

I agree with the teaching theory of keeping it as simple as practicable. Elevator controls pitch with reference to relative wind, and therefore airspeed. Rudder controls yaw with reference to the way our butt is going. Aileron controls roll around the longitudinal axis, or what is commonly called bank. Leading rudder and then coordination of rudder and aileron increases the efficiency of the roll into bank, but rudder is more effective by itself to control gyroscopic precession when we bring the tail up and p factor when we bring the nose up and to bracket the centerline or centerline extended or to bracket any distant target, which also keeps the wing level. Finally, when we pitch with elevator to decelerate on short final causing less relative wind over the wing and thus sink or mush, throttle becomes a very effective glide angle and rate of descent control.

We are taught that coordinated aileron and rudder bank the wing so that elevator can then be pulled up to effect turn. While true, this is dangerous orientation. If we suddenly need to turn to miss obstructions or another aircraft, we may believe that pulling hard on the yoke will increase the rate of turn. If, rather, the nose is allowed to go down as designed for safety, rudder will safely increase the rate of turn more than will the small amount of elevator back pressure that can safely be pulled with large bank angle before stall. By the way, the lift of the banked wing does far more turning than the pull (zoom lift) on the elevator. And that zoom lift goes away quickly. And the lift component of increased thrust (good idea) is not much in small airplanes. Many of our trainers will pitch down when we attempt an accelerated stall and enter a graveyard spiral rather than stall. Finally, slipping in the turn with insufficient rudder, a common error, will retard the rate of turn more than the amount of elevator that can be pulled before stall will increase the rate of turn. Rate of turn will increase when we pull the elevator full back...and spin.

We are taught that rudder controls yaw only, but we see rate of turn increase with rudder yaw and rudder yaw pitches the nose down when the wing is banked. This is very obvious at 45 degrees or greater bank angle. We are taught to direct our course with coordinated turns to target or heading. But this wing wagging prevents attainment of longitudinal axis alignment with the target. Rudder is most effective in directing our course to the target and at the same time keeping the wing level.

The reason that Cessna's emergency rudder turn, for non-instrument pilots to reverse course safely in inadvertent IMC, works is that the rudder yaw speeds up the outside wing and this increased lift banks the airplane. Next the wing, not the elevator (hands are on lap) turns the airplane with some lift diverted to the horizontal. If we are able to remove our hands from the yoke, neither adverse yaw nor overbanking will kill us. We will lose a little altitude and that will not kill us. Rudder, mounted on the longitudinal axis, gives more reliable control than the aileron outboard of the longitudinal axis. Yes, the rudder is an inefficient roll control. That is what makes it a great emergency turn control.

Aileron is the most used and preferred control because it is most like the steering wheel on the automobile. Because it is at the outboard end of the wing and receives no prop blast, it doesn't work well at slow airspeed. When down, it increases camber on the outboard part of that wing for greater lift verses the other wing with up aileron. This down aileron yaws that wing back. So as the yaw control, the rudder, is capable of turning the airplane, the bank control, the aileron, is capable of yawing the airplane. There goes our simplicity.

Finally we have my favorite glide angle and rate of descent control, the throttle. The book, always right, says it is for thrust, which seems like airspeed. But on tractor mounted engines, it also provides lift. That is why it helps so much with glide angle and rate of descent control. But to have that fourth control, we have to have neither full throttle nor closed throttle continuously. We have to decelerate enough to sink or mush to make the throttle effectively control glide angle and rate of descent. And yes, the elevator can simultaneously control both airspeed and altitude when zoom reserve airspeed is available. Once zoom reserve airspeed is used up, we sink with up elevator. Further attempt to continue using elevator to maintain altitude wings level, or especially in a turn, results in stall or graveyard spiral. And yes, the throttle can increase or decrease airspeed at a given pitch attitude set by elevator. In the airplanes we fly, however, throttle pales in comparison to the power of gravity at lower pitch attitudes. If we let the nose go down naturally in turns, we access much greater energy than what can be provided by the engine to maintain altitude and keep the wing alive.

Wow Contact, that was a lot to write, read and digest.. Still digesting. Thanks

Best,

Tommy

"Maintain altitude and keep the wing alive." Now there, in much of the natural world, is an oxymoron.

Hang in there Tom. It is not dark matter, just that those who decide what's what in the books haven't always followed Ronnie's good instructional technique: "Move the controls. how else are you going to know what they do?"

While not considered a control, we probably should consider the wing itself. In level flight it lifts the weight to maintain altitude. The more we bank, the greater amount of that lift is diverted to pull the airplane in a horizontal direction, to turn. Pulling back on the yoke both accelerates the turn and still lifts the airplane to maintain altitude, but there is a limit. If we have increased pitch attitude rather than increased thrust to make up the lift lost to the turn, we will lose airspeed. If we bank enough that both increased thrust and increased pitch attitude will no longer maintain altitude, we will either stall, spin, or spiral. The recovery from any of these outcomes is to pitch down or reduce bank angle or both and that recovery requires altitude we do not have in the pattern.

So the school solution is to limit bank angle. This is fine, maybe, until horizontal space becomes limited by obstructions or other aircraft. Also there is a need to utilize aircraft in low altitude work requiring turns to near targets.

The crux comes at around 45 degrees of bank where most of the airplanes we fly will no longer maintain altitude with full power. At 45 degrees of bank we are splitting wing lift against weight and wing lift to turn 50-50. Pilots engaged in low altitude work requiring much faster than standard rates of turn to miss terrain and obstructions and to get the longitudinal axis aligned with the target before a down wing strikes a wire or obstruction or terrain have learned to manage energy to maximize turning efficiency. By pitching up we trade cruise airspeed for altitude until airspeed is reduced to allow increased rate of turn and decreased diameter of a 180 degree turn. That increased altitude is then traded for increased airspeed in the pitch down that happens naturally if we simply don't pull back on the stick or yoke in the turn. Lots of ruder is required because we are slow and because we bank more than necessary to begin the turn and keep rudder pressure as necessary to keep the nose moving appropriate to the angle of bank.

At 45 degrees of bank, the rudder is pushing the nose down as much as yawing the nose around to counter adverse yaw of ailerons and to leverage against fuselage dampening and to stay with the increase in bank that happens naturally because of dihedral beginning at around 45 degrees of bank.

Finally, in the pattern there is no need to bank 45 degrees or greater unless obstructions or airplanes get in the way. However, on most legs of the pattern we are at less than cruise airspeed. We have less airspeed to keep the wing flying in turns. Limiting bank while trying to climb or maintain altitude may work just fine...or not. The zoom up part of the energy management turn is not available without airspeed. We can, however, simply allow the nose to go down naturally as designed for safety. We do not have to pull back on the stick except on the flight test. ATC will not dock our pay unless we climb or maintain altitude in all turns. Turn safely. Lead rudder an then bank and then release the yoke and let her have her head. The design of the airplane is to fly. Only the pilot (or computer) can cause stall.

Keep on Preachin & Teachin Brother .

I just watched a u-tube video where the DPE, while explaining the difference in slip and skid, valued the slip for altitude loss without increase in airspeed and ease of spin recovery from stall while slipping. He saw no value whatsoever in skidding. Given the maintain altitude in all turns no matter what orientation, that is good thinking. He has overlooked the use of the skidding turn in the Cessna no hands emergency turn back for non-instrument pilots who inadvertently enter IMC, however.

A word of caution about the energy management turn or just allowing the nose to go down naturally in all turns: This is a completely different orientation than the maintain altitude at all costs orientation. Like VMC or IMC are totally different orientations and mixing can be dangerous, so too are V speed and altitude orientation and energy management totally different orientations. Skidding turns in low ground effect and the half standard rate rudder only skid to turn back from IMC are special situations. In energy management turns or just allowing the nose to go down, we are skidding with a low pitch attitude. We have lots of effective relative wind over the wing from utilizing the potential energy of altitude, going down hill.

Back to the DPE and the slip vs. skid spin. In slip the wing away from the turn, the up wing stalls. According to the DPE this is an easy recovery because we return to level. True with intentional spin for training. In the stall spin videos I have seen in the pattern, the up wing stalls and the down wing goes over the top. The delay because inadvertent is the difference. For those who work all day at low altitude, recovery is not the orientation. Prevention is the orientation. And the dangerous downwind base to final spin in maintain altitude, limit bank orientation is considered the killer.

Pulling back on the stick in the turn in the sometimes futile attempt to maintain altitude is the killer, not spinning from a stall while slipping, not spinning from a stall while skidding, not from stalling in a coordinated turn. The cause of all stall and spin accidents is the pilot pulling back on the stick to increase pitch angle in reference to relative wind for some reason.

The reason the Cessna emergency turn back from inadvertent IMC using rudder only to get a half standard rate of turn (halfway to the doghouse on the old turn and bank instrument) was entirely stall proof was that the pilots hands were to be in his lap. No pull back on the yoke, no stall. Why no stall? Because the nose will go down naturally as designed for safety. Some loss of altitude. What is down there? Better visibility.

Yes, we instructors sometimes want that smooth (if we lead rudder) and level coordinated two minute turn. It is most effective when flying by reference to instruments where we want to maintain altitude and airspeed. If thrust replaces the lift lost to slight banking, no back pressure on the yoke is necessary. Even if we have to use a little back pressure on the elevator, little airspeed is lost. Even if we slip around causing a bit more than two minutes for the standard rate of turn around, we are up in the atmosphere where nothing is in the way. This high altitude orientation requiring maintenance of both altitude and airspeed are appropriate at altitude. The airplane almost flies itself here. It would do the same at low altitude and when we were trying to line up with targets like the runway centerline. It would only become dangerous when tailwind forced us to bank enough to increase rate and decrease diameter of turn enough to align with the centerline extended or when terrain and obstructions limited horizontal space available requiring increased rate and decreased diameter of turn.

The standard rate level turn is not sufficient to the needs of those who work at low altitude continuously. It has safety implications for the standard traffic pattern as well.

tps://www.youtube.com/watch?v=8k8PeC9n_8Y Ed Wischmeyer's zoom meeting on cognitive unavailability brought up the opinion or fact that some or many of the NTSB or FAA determined probable cause of stall spin could actually have been spiral to ground accidents, what we used to call the graveyard spiral.

When we want to stay over the key position while losing lots of altitude to get down to a selected forced landing zone, we enter a descending turn and then pull back on the stick enough to reduce relative wind enough to cause rapid spiraling down. When low enough to make a turn to base, we lead rudder and then coordinate rudder and aileron to level the wing. This returns us to normal power off descent with normal power off rate of descent.

The spiral that ended up being a graveyard spiral accident event with the Malabo at Oshkosh was different. It started as a normal descending turn and became a graveyard spiral only when the pilot pulled up hard on the yoke to reduce rate of descent without first leveling the wing. As Ed pointed out, this could have been cognitive unavailability on the pilot's part. The fact that one wing was still down in a steep bank could have been the Gorilla we don't see because we are only with lateral or vertical control. Or he could have been oriented on the turn to centerline, the lateral control, to the exclusion of the vertical. In this case it would be just flying into the ground rather than graveyard spiral.

Regardless, the graveyard spiral is caused by wanting to deal with vertical pitch down to the exclusion of lateral wing leveling. We do that by pulling back on the stick strongly. Cognitive unavailability could be a factor in this. Maintenance of altitude at any cost orientation is certainly a factor.

In the interest of safety, should the elevator be taught as and used as the primary turn control? It certainly is going to increase g loading and thus the load factor problem on the main wing. The only reason we end up with spiral rather than stall spin with the kind of airplanes we fly is that at steeper banks, we simply cannot keep the nose up on the horizon. The nose is going down naturally, trying to save us, no matter how hard we try to kill ourselves. So we may spiral in without the stall spin we are attempting so earnestly.

The horizontal lift of the banked wing is what turns the airplane. Pulling on the elevator can increase pitch in reference to relative wind. This both slows the airspeed and increases the lift of the main wing so long as zoom reserve airspeed is available. Once the zoom airspeed is used up, the nose is going down as designed for safety. That is unless we have already stalled the main wing by pulling back on the elevator.

The safety dynamic stability of the airplane is such that paying attention to what the airplane wants to do is very useful in the development of good control manipulation. The main wing wants to get us up when it will fly in low ground effect, but it doesn't want to climb up through the lift help of low ground effect. In short field work, we can use flaps or back pressure on the yoke to get into low ground effect quicker. When we do that the airplane wants to pitch back down to stay in low ground effect. Holding the yoke back will delay acceleration and cause descent rather than assent. Pushing the yoke forward too fast will cause the mains or even the nose wheel to touch back down. At this slow airspeed, we have insufficient elevator to put the prop into the surface. Dynamic proactive bracketing of level in low ground effect works well. A good guide, however, is what the airplane wants to do. It wants to pitch back down to stay in low ground effect.

Once off into the atmosphere, the airplane wants to pitch up in updrafts and to pitch down in downdrafts. This is designed stability in reference to relative wind and is very energy efficient. Unfortunately, the exact opposite of this happens when we try to use elevator to maintain altitude. By pushing forward in updrafts we refuse the lift energy of updrafts. By pulling back in downdrafts, we not only stay in them longer but we also decrease airspeed. If we decrease airspeed below DMMS, we have given up important maneuvering airspeed when now possibly low enough to have limited horizontal space for maneuvering. The worse case scenario is if, as the downdraft takes us too low to recover from stall, we pull to hard fighting it and stall. This one is sometimes explained as the downdraft slammed the airplane into the ground and is usually fatal.

Finally there is a place where the designers were unable to insure good use of the dynamic stability. In order to land, we need to defeat the good flying (not stalling) design features of the airplane. Giving up the dynamic glide angle and rate of descent control of the throttle leaves us with an elevator that now must control both airspeed (which it is very good at) and altitude (which it is variable about.) When we have zoom reserve in the form of airspeed (DMMS up high and Vso in low ground effect) pulling back on the elevator will cause climb. When we have less than DMMS up high and less than Vso in low ground effect, we will descend in a pitched up mush. Pulling back is what causes stall, not good up higher but exactly what is desired in low ground effect.

Concerning Ed's cognitive unavailability, high altitude orientation (living mostly up there) gives pilots fewer iterations of vertical space limited maneuvering. While high altitude is safer, low altitude orientation and turn to target muscle memory may not develope. So when rising terrain ahead and on both sides (up valley) require energy management, zoom reserve in airspeed to gain a bit of altitude to slow down to reduce diameter of turn and giving up that gained altitude for airspeed resumption in the turn may not be drawn upon. A slowing airspeed but with larger diameter and with no altitude gain level turn toward higher terrain may not work.

Low altitude maneuvering keeps both vertical and lateral cognitive availability in the game. The law of the roller coaster and allowing the nose to go down in all turns are constant considerations. In Ag or pipeline patrol, this happens a thousand times a day. The application and absorption of this energy multiplier can be available to overcome upset, near miss, and other potential problems.

Expecting the controls to work like we have been taught that the controls work, without actually moving them grossly to see the full extent of what they actually are capable of, is a dangerous abdication of Pilot in Command responsibility. Actually it is a gross abdication. "Move the control. How else are you going to learn what it does?" How else are you going to have cognitive availability?

"Forced to land in Waco," an article by Al Cercone in the latest Air Facts Journal, has an interesting use of rudder only to skid segment. He had to line up with a fence line and also go over a bull and under a high voltage power line and smartly chose not to make a coordinated turn and put the down wing into the bull and the up wing into the wire. He thought the forward swept vertical stabilizer and rudder was what made that possible. It is possible, when we have maneuvering airspeed, in any airplane, save the poor Ercoupe. Move the controls. How else are you going to know what they are capable of?

Jaun Brown does a good job on U-tube, in his Mighty Luscombe, explaining how the common reactions of pulling back on the stick when the ocean is coming up and using aileron instead of rudder can be as fatal in a F-14 as in the Luscombe. Our interest is more in the Luscombe and all the various airplanes we fly that also will do bad things only if the pilot uses the wrong controls to solve upsets. Why is rudder primary? Because of where it is mounted on the airplane. It reliably does what it was designed to do, including leveling the wing when slow enough for adverse yaw of aileron input to stall the adversely affected wing. It reliably levels the wing anytime large heading change is not desired. Aileron is not primary because it does not reliably do what it was designed to do but actually does just the opposite initially. Adverse yaw means bad yaw. Don't go there when slow. Rudder means good yaw. Go there to level the wing when the outcome of the original maneuver is in doubt or you need to level the wing while maintaining longitudinal alignment with a target.

Use the rudder. How else are you going to learn what it does? Use it grossly. Use it a lot. As an aid to aileron (coordination,) it can get left out of the equation from slight to none usage. We don't know much about controls we seldom use aggressively enough to see what they do.

Good post Jim. I hadva heck of a time flying the R66 the other day. Anytime it started to lean, my first reaction was to kick opposite rudder. Unfortunately it doesn't work the same in the chopper as the airplane. Took a bit to get my brain switched back to moving the stick instead.

That is the Butch Washtock "lead rudder," coming out in you David. Which is good. I always coordinated anti-torque pedals with cyclic in helicopters too. In the Cobra in a 90 degree bank, the tail rotor tip path plane is pointed straight up. Left pedal will push the nose straight down onto the target. That way we could work in a really tight 40 kts circle to the left going around the loach. The low bird was bait, but we wanted Charlie to know we were covering him. The cadence of the whap whap became double time in such a tight turn making Charlie get his head down and quit firing on my low bird, which was good. We were hunter-killers in a war of attrition, but we really just wanted to make it back home. We showed up, and that made an impression on both China and Russia.

Uncle Ho & Mao didn’t want to fool with you Jimmy . Vlad is still scared shitless of you .
Thanks Brother and we raise a glass today to those that never came Home .

Primary controls are flight controls that will attain a desired result by themselves not requiring coordination with other controls to be safe. Forward throttle will always increase lift even though coordination with elevator gives better control of desired rate of climb. Elevator will always control the pitch attitude with reference to relative wind. And rudder will always control longitudinal alignment directing our course to a target either by pointing the nose at it or by directing our butt (center of gravity) in crosswind toward it. Rudder will level the wing by itself at any airspeed that the wing is still flying and not falling. Aileron will not do that. Aileron, because of adverse (wrong way) yaw, must be used in coordination with the rudder and rudder must lead to prevent the nose from going the wrong way initially.

Throttle (thrust), elevator, and rudder are all aligned with the longitudinal axis (single engine). They are primary in that application. Aileron is out on the end of the wing well away from the longitudinal axis and therefore is secondary in that application. Dynamic balance of aileron would require differential travel being controlled in a non-adverse yaw way as with the Ercoupe. The aileron becomes primary in this application. Both down and up ailerons are moved irregularly to eliminate adverse yaw. The down aileron goes down a slowly and minutely and then much faster as the yoke is moved further. The up aileron goes up rapidly and a lot and then lessens as the yoke is moved further.

Wing engineering in all other models of airplane, save the computer flown like B-2, mitigates but does not eliminate adverse yaw.