Myron Collier

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Lazy-Rudder Syndrome

Lazy-Rudder Syndrome

by Myron Collier

Profile From time to time there is talk among those in the flight training arena about the merits of reinstating the requirement for spin training at all levels of pilot training and certification, as it existed several decades ago. The issue asks a simple question -- "Would spin training for private and commercial pilot applicants have any tangible benefit in terms of improving overall safety?"

Earning my private pilot certificate in 1947, commercial pilot certificate in 1948 and as a young flight instructor in the early 1950s, I have experienced my share of spins. Has this experience in itself made me a more capable or safer pilot -- probably not?

Accidental spins usually occur at low altitudes when doing such things as making the turn from base to final or buzzing someone's house. Under these or similar conditions a recovery is highly unlikely, even if one had previously undergone spin training. Pilots who have had spin training know how to recover from them, but at low altitudes they don't have the room needed to apply what they have learned.

Prevention is the key to avoiding these situations. Almost without exception, improper use of the rudder is the primary contributor to an accidental spin. What can be done to decrease the chance of an accidental spin? Perhaps returning to the "basics" would be appropriate. This falls directly in the lap of the flight instructor. Before the flight instructor can be an effective teacher to address this issue, he must fully understand the role the rudder plays in the scenario.

During the 46 years this writer has served as a designated pilot examiner (DPE), it has become apparent that many (if not most) contemporary pilots suffer, at least to some extent, from what I call "Lazy-Rudder Syndrome." In other words, they simply don't use appropriate rudder response when required. Rather, they attempt to "drive" the airplane with inputs from the yoke with little, if any, rudder input.

Tricycle gear vs. tailwheel, yoke vs. stick...

Why is this? In my view the root cause lies primarily with the tricycle landing gear and yoke control. Many years ago training-type aircraft had what was then called a "conventional" landing gear. In other words, the aircraft had a tailwheel. Initially, just learning to taxi one of these "tail-draggers" was a challenge in itself.

With time the student soon got the hang of it and the required rudder inputs to make the airplane go where he or she wanted it to go. This resulted in a conditioning of the student's reflexes. This conditioning became so well-ingrained that at the first hint of any directional deviation, on the ground or in the air, immediate and appropriate rudder response was initiated without conscious effort. This development simply doesn't happen to the same degree when learning to fly in a tricycle-geared aircraft.

The inherent tendency for contemporary pilots to suffer from lazy-rudder syndrome is reflected in Federal Aviation Regulation 61.31(i) (1), which reads in part:

"No person may act as pilot in command of a tailwheel airplane unless that person has received and logged flight training from an authorized instructor who found the person proficient in the operation of a tailwheel airplane."

Although this requirement is grandfathered for a person who has logged pilot-in-command time in a tailwheel airplane before April 15, 1991, the inference is clear for all pilots.

It has been reported by some flight instructors in both tailwheel and tricycle-geared aircraft that, even though rudder response was adequate when operating a tailwheel aircraft, any conditioning derived thereof was soon forgotten when flying the more traditional and forgiving tricycle landing gear aircraft. In these cases it would appear the conditioning process had not been sufficiently developed to come into play, regardless of the type of aircraft being flown.

In addition to a tailwheel, aircraft used for flight training during earlier years had a "stick," as opposed to a yoke or “wheel.” When driving an automobile one subconsciously turns the wheel in the opposite direction when the vehicle starts to drift to one side of the road or the other. This also is a conditioned reflex. Unfortunately, this conditioning carries over to airplanes equipped with a yoke control. A stick, unlike a yoke, provided little similarity to an automobile's steering wheel and a pilot trained in a stick-airplane was less likely to attempt to "drive" the airplane.

Aircraft designs of the 1930s, '40s, and early '50s were generally not as aerodynamically "forgiving" as current designs, and using the ailerons during a stall recovery was a no-no. With these aircraft, attempting to pick up a wing or maintain directional control during a stall recovery with ailerons was cause for failure of a flight test. The flight-training manuals and Flight Test Guides of that time emphasized, "Only the rudder is to be used to maintain directional control during stall recoveries."

Quoting from Civil Aeronautics Administration Bulletin No. 32, June 1943, "Fundamentals of Elementary Flight Maneuvers" (Yes, I still have those old manuals), it was emphasized: "The wings are to be held level without the use of ailerons."

These mandates should be recognized and given heed by contemporary pilots restoring and flying these grand old vintage birds.

Why did this bulletin and other training manuals stress using the rudder to keep the wings level? To spin, an airplane must first be in a stalled configuration and, while in that configuration, "allowed" to rotate. If the airplane is prevented from rotating it cannot spin. It is the rudder that is the key to preventing rotation.

Aircraft that initially came onto the market following World War II were primarily designs that existed before the conflict. Eventually some of these aircraft, along with entirely new aircraft designs, were given various aerodynamic enhancements that came into play when approaching and during a stall. Of particular note were differential aileron travel and wing-washout.

...and forgiving aerodynamics

As any CFI knows, differential aileron travel provides that the down-aileron deflects into the slipstream to a lesser degree than the up-aileron, thereby, minimizing adverse yaw. Adverse yaw can have a villainous impact on various aspects of controlled flight.

Differential aileron travel is not restricted to only training aircraft. For example, the Citation II provides for differential aileron travel by the up-aileron extending 19 degrees, while the down-aileron extends only 15 degrees. This may not seem like much, but it results in a decrease in adverse yaw that has a direct impact on required rudder response.

Frise-type ailerons can also address adverse yaw. Although perhaps not common on typical training-type aircraft, the Frise-type aileron provides for the structure's leading edge to project into the airflow, thereby, increasing drag. Unlike a conventional aileron design, the increased drag contributes to a decrease in adverse yaw. In addition, the "slot" afforded by this design makes the aileron more effective at high angles of attack by disciplining the airflow over the structure's surface. However, despite this feature some rudder is still needed whenever ailerons are applied.

Wing-washout provides for a decreased angle of incidence from wing root to wing tip. Thus, at the onset of a stall, the stall occurs at the wing root and progressively moves outwardly toward the wing tip. This results in increased aileron effectiveness during slow flight and, to some degree, during a stall.

With embellishments of this nature applied to a wing's platform it has now become acceptable practice, according to FAA's current Flight Training Handbook, to use aileron inputs during a stall recovery. However, it gives this caution:

It is important that the rudder be used properly during both the entry and recovery from a stall to counteract any tendency of the airplane to slip or yaw, the latter being a prelude to a spin.

Talking about the proper use of ailerons and rudder means little if pilots do not acknowledge their interaction in flight. Having conducted pilot certification flight tests for over four decades as a DPE, it has become abundantly clear that many contemporary pilots don't fully comply fully with FAA's intent in the use of ailerons during a stall recovery. In many cases, the rudder pedals appear to serve only as foot rests. Or simply put, the pilot suffers from lazy-rudder syndrome.

How can flight instructors address lazy-rudder syndrome when training pilots, including those who may have learned to fly in a tail-dragger but have since fallen victim to lazy-rudder syndrome? Recognizing that the condition exists is a good place to begin. Lest it be thought this applies only to the student or private pilots, rest assured it applies to all levels of pilot certification and experience, including the flight instructor.

Improving stick-and-rudder skills

What then can be done to address lazy-rudder syndrome? There are several excellent training exercises that can contribute to strengthen one's basic stick-and-rudder skills.

When taxing the aircraft, keep one's hands off the yoke, unless wind and surface conditions suggest otherwise. This reinforces the pilot's subconscious that the rudder is the major contributor to the airplane's "direction" (yaw), not the yoke. It is not uncommon to see an applicant for a pilot certificate turn the yoke in the desired direction when taxing the aircraft. Almost assuredly, this tendency will be demonstrated in flight as well.

From time to time the instructor should have their students completely remove their hands from the yoke during a climb, as well as in straight and level flight, using only soft applications of the rudder to maintain directional control. If a wing drops slightly, as it will likely do at some point, smoothly applying opposite rudder pressure in a timely manner (human yaw damper) will return the wings to level flight. It can be expected the student will initially display difficulty when in flight to completely remove his/her hands from the yoke. This is not unusual and is a subtle reminder of the presence of lazy-rudder syndrome.

It is also important that the aircraft be in proper trim, particularly in its roll axis. Because many training-type aircraft do not have in-flight capability to adjust roll-trim, trial and error adjustments of the aileron's manual trim-tab (if provided) may be required to achieve the desired results.

These exercises cannot only have a positive impact on developing one's rudder reflexes, they can also have a more subtle value as well. When conducting an Instrument or ATP flight test, I have observed that when the applicant attempts to change a radio frequency, review a chart, etc., the aircraft will pitch up/down or drop a wing due to unintended control inputs. If a pilot simply removes one's hands from the yoke, and with a little timely assistance from the rudder to maintain directional control while attending to these needs, the aircraft will remain in straight and level flight remarkably well. When I offer this suggestion to an applicant during a flight examination, the reaction is often one of, "If removing one's hands from the yoke an immediate loss of control will occur." Needless to say, it will not.

Another skill that seems to have lost some importance over the years is one of coordination. Proper coordination of the flight controls is often viewed as a mark of a proficient pilot. As a young lad determined to fly airplanes for a living when I grew up, proper coordination became one of my top priorities. The rudder certainly plays an important roll in coordinating flight controls

An excellent training exercise for the development of coordination skills is a maneuver called "turning about a point." In straight-and-level flight, a point is picked on the horizon. The aircraft is then rolled into a turn, and after turning perhaps 15 degrees or so, the turn is reversed. This is carried to the same degree on the other side of the point, and so on. This is an excellent maneuver to develop coordination skills and can be extended into a climb where the torque affect must be recognized and dealt with to achieve coordinated flight.

Takeoffs and landings

Of the repertory of aerial maneuvers, evidence that a pilot suffers from lazy-rudder syndrome is perhaps greatest during the initial lift-off and during the approach and landing exercise, particularly when dealing with gusty crosswind conditions. On rotation, to correct for yaw generated by torque (P-factor if you prefer), the pilot is likely to react solely with an input from the yoke. During approach and landing as turbulence-induced yaw rocks the aircraft from side to side, invariably the applicant will attempt to counter these motions with yoke inputs, with nary a budge of the rudder. This not only doesn't't get the job done, it exacerbates the very thing the pilot is attempting to counter.

I recall when conducting a Private Pilot test on final approach the applicant was experiencing some difficulty by attempting to deal with yawing motions induced by light turbulence solely with inputs with the yoke. Noting he was tiring, I asked if he minded if I "take it around once." On final approach, I dealt with the same yawing motions the applicant had experience, but with appropriate rudder response. The comment by the applicant is one I shall never forget, "The wind died down for you." In other words, he was inflicting much of the so-called turbulence upon himself with inappropriate responses from the yoke.

One may get away with poor coordination and improper rudder response during routine flight operations, but when dealing with a gusty crosswind landing such indifference is often a prelude to an incident, if not an accident. For example, when negotiating a crosswind landing and the longitudinal axis of the aircraft is suddenly yawed askew, responding with only an input from the yoke not only increases the yawing motion momentarily, it raises the wing and there goes any required crosswind correction. Simply stated, the rudder is used to maintain the longitudinal axis of the aircraft aligned with the runway centerline, and the ailerons are used to lower the wing sufficiently into the wind to affect a side-slip and, thereby, offset wind drift. Sounds simple enough, doesn't it? If the rudder and ailerons are used properly, it is.

The contribution the runway's white centerline can provide is often overlooked. One should strive, both on takeoff and landing, to straddle the centerline if one is available. When landing, the centerline provides an immediate point of reference to show if proper drift correction is applied, as well as an aid for longitudinal alignment of the aircraft. Similarly, it is an excellent aid to maintain directional control when taking off.

As a fledging aviator I recall a crusty old CAA inspector (Civil Aeronautics Administration in those days) telling a story of giving an aspiring airline pilot a flight check. According to the inspector, the pilot would touch down on one side of the runway and the next time on the other side when landing. The inspector, displaying a degree of wit, addressed the situation by simply saying, "Son, you can land anywhere on this runway you wish. But remember, the centerline is reserved for captains and potential captains." That is a good thought to keep in mind, whether captain of a light single engine or captain of a large multiengine aircraft.

When faced with these conditions, pilots must discipline themselves to adhere to the fundamental principals that apply: "Use the rudder to maintain alignment of the aircraft's longitudinal axis with the runway centerline while concurrently maintaining any required wing-low adjustment to counter for wind-drift." Unlike non-turbulent air conditions where coordinated control inputs are the norm, in crosswind conditions the feet and the hands may appear to operate independently, if not counter to each other. This is as it should be.

This becomes particularly critical during the flare and initial contact with the runway. If directional alignment and drift corrections are not maintained, the aircraft will touch down in a crabbed attitude, not unlike that of an automobile sliding sideways on icy pavement onto dry pavement. When this occurs, a landing incident, or perhaps even worse, an accident, is highly probable.

Self-evaluation

Admitting to one's self that one's stick-and-rudder skills have deteriorated, or perhaps have not been fully developed, may not be easy to accept. This can be particularly difficult for the flight instructor with whom the responsibility lies for the training of proficient and safe pilots. However, recognizing the need for improvement of one's stick-and-rudder skills can be the first step to becoming a more proficient pilot, as well a safer pilot. Performing and teaching properly executed maneuvers on the part of the flight instructor are indicative of not only professionalism, it becomes the mold that determines the quality of the product the instructor produces.

Do you suffer from lazy-rudder syndrome?