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Joe Godfrey |
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Lazy-Rudder Syndrome
by Myron Collier
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?