…Angle of Attack; ...Controls
and What They Do; ... Anticipation;
...Holding Headings; ...Oh,
that right rudder;
...Level Dynamics; ...Turns
lesson; ...Leveling Off from Climb;
...Level Cruise #1; ...Level
Cruise #2; ...Level Cruise #3; ...Unable to fly level; ...On
making turns; ...Why turns turn; ...Level Turn Dynamics; ...Bank
recovery to a heading; ...Level Turns;
...Level turn exercises; ...Climbing
Left turns; ...Climbing Right turns;
...Steep Turns; More
Thoughts; ...Second Way; …Steep Turns (Basic); …Steep
Turns (Complex); …VSI in Slow
Flight and Steep Turns; …Downwind
turns; …Impossible Turn;
…Clearing Turns; …Graveyard
Spiral; …
Your learning progress is directly related to your understanding
of how the controls affect flight. Accidents are the ultimate
solution of a lack of understanding. A pilot must understand the
function of the rudder and angle of attack related to flight.
By definition, the angle of attack is the angle made by the chord
line of the wing and the aircraft flight path. At a certain critical
angle of attack a wing or a part of it will stall regardless of
speed or load factor. Stall warners are used because AOA
indicators are difficult to install on small aircraft and even
when installed the AOA at stall varies however slightly.
A wing can produce lift by increasing the AOA until reaching the
stall AOA. AOA is controlled by used of the elevators. Any increase
in speed will increase the lift. In straight a level flight lift
is equal to aircraft weight. The fact is, airspeed does not cause
a stall, AOA causes a stall regardless of speed or load factor.
Load factor can be increased by turns, abrupt control movements
and dive recoveries. In these instances the aircraft may stall
at a higher speed because of the load factor but the AOA is always
the same. Load factor 3.8 corresponds to load factor needed to
maintain level flight in a 74.7 degree bank.
There is a relatively wide range of level flight speeds. A pilot
can by varying power and AOA, one against the other, transition
through all the level flight speeds. A fixed power setting and
AOA allows a pilot to trim for a hands-off airspeed. Changes of
power only in a hands-off flight situation will cause the aircraft
to change the nose, up or down, and, with dampening by hand, the
aircraft will climb or descend at very near the original speed.
There is controversy between the aviation guru Wolfgang Langewiesche
and the FAA as to what flight controls do. Regardless, to place
the aircraft into a given position the same essential movements
are required. Elevators do control the angle of attack and in
so doing they control airspeed. Elevators do not 'elevate' the
aircraft except by converting excess airspeed into altitude. The
primary factor used to 'elevate' an aircraft is excess power.
The landing process is best stabilized by setting constants. Power
is the first and easiest constant to set. With power set the elevator
becomes the speed control and trim is the 'lock' that will set
a constant speed. Once a locked constant speed is attained, small
power reductions can be used to control the glide path descent.
Maximum power is used to intercept a higher glide slope.
Controls
and What They Do
When engineered, an aircraft will have controls that are designed
to give a 'feel' of solidness. This design is there to prevent
over control. Almost any aircraft can be torn apart but too abrupt
control movement. This is why knowing the Va speed is so important
to a pilot. Aircraft controls by design try to warn the pilot
of potential dangers by providing feedback. Every control movement
gives the pilot a 'feel' for what the aircraft is doing. Designs
for differing purposes set the control force required for a given
maneuver.
Designers try to harmonize the control forces around the three
axes. The standard control force rations are 1:2:4. The roll axis
force is 1. The pitch forces are 2 or twice the roll axis required
force. Rudder forces are 4 or twice the pitch forces required.
The axes are the basic elements. The placement of controls and
their required forces are built around the force capabilities
of the human body.
Since the movable control surfaces are distant from the pilot,
the use of rods, cables, chains, and associated levers, pulleys,
hinges and horns are needed to provide the connection and desired
movement. An unwanted factor in this connection is friction. Frictional
forces have a negative effect on a pilot's ability to trim and
stay trimmed. Friction can be the subtlest force faced by a pilot.
When trimming and staying trimmed becomes a problem, suspect friction
as the culprit.
The 'feel' on the controls is proportional to the airload on
the control surface. A control has a neutral or trimmed condition
in normal flight. The further from this condition the surface
is moved by the pilot, the greater becomes the control force required.
This occurs even at slower airspeeds. Control 'feel' is a tactile
pilot indicator to be added to wind noise, propeller beat and
engine sounds as an airspeed indicator.
Student pilots must be taken through basic maneuvers so as to
learn by experiment how control force feels. Once these forces
and their changes have been experienced they can easily be transferred
from aircraft to aircraft just as we do with automobiles. Once
you learn to fly smoothly in one aircraft you can learn quickly
to fly in another. Engineered force-feedback is basic to all aircraft
design. A pilot does not watch the yoke move; he feels the movement
and the pressures.
Feel and movement of the controls can be altered in an aircraft. Spades, servo tabs, counter weights, springs and aerodynamic design are commonly used by engineers to affect changes. Size, strength, and placement are used to reduce some of the forces required by the pilot. From a given trimmed condition every control requires an initial force to make it make its initial move. This beginning force is called 'breakout'. If this required force were not there it would be impossible to fly smoothly while holding a control. With 'breakout' force required a plane's controls will only move when intentionally forced past the 'breakout' pressure. The 'breakout' force is a very carefully selected item of control. It must be there to prevent the unintended pressures and yet allow very small-intended pressures to have effect.
The primary controls are the elevators, ailerons and rudder.
These provide primary movement around the axes of flight. In combination,
they give coordinated movement around the axes of flight. Engine
power is an additional primary control of pitch. Again, in combination,
it gives coordinated movement. No change in one axis occurs without
having some effect on the other axes.
Secondary controls include trim and flaps. Devices that augment
engine power and control operations, weight, center of gravity
and load factor have secondary effect on control. Complex aircraft
may have additional controls. The effect on all controls is dependent
on conditions of altitude, speed, temperature and weather.
Neutral pitch is engineered into the placement of engine, wings.
horizontal stabilizer and loading limits. The pitch is moderated
to a designed degree by elevator, engine power and trim. Any change
in elevator or engine power along with the rapidity of change
requires coordinated control movement in the other axes. To change
only pitch, by whatever means, some additional combination of
rudder and aileron is required.
Ailerons "control" bank angle, roll and roll rate but,
in combination with the other controls. On application of aileron
in a turn, rudder must be "coordinated" to keep the
tail behind the nose; elevator is used to counter loss of vertical
lift. Ailerons work in opposite directions, usually in differing
distance and with an effect called adverse yaw. The down aileron
gives lift and drag (induced). The drag resists the turn so that
rudder is applied for coordination.
Rudder is used most often in anticipation of known requirements
from the other controls. Rudder will induce roll as well as yaw.
The rudder can be used to raise a wing in a stall. Anticipatory
rudder is applied to counter the effects of power/pitch applications.
A rudder applied yaw is used to make possible crosswind landings.
P-factor, torque, precession and slipstream all require use of
the rudder. Skillful rudder on the ball and in anticipation is
the distinctive mark of a good pilot.
Power is a pitch control. Just adding power (no other control
input) will cause the nose to rise and roll to the left. Speed
will decrease. In a turn, power will make the left turn possible
with little or no rudder but require rudder to "lead"
the right turn. There are countless cause/effects in the creation
and control of a given airspeed and pitch condition. If you are
ever asked about what controls airspeed and pitch, just say, "The
pilot".
Anticipation
The ability to anticipate changes in control pressures required
for a particular maneuver must be developed. Failure to anticipate
rudder movement required to move the nose as airspeed decreases
is a most common flight error. The behavior of instruments such
as the airspeed indicator and vertical speed indicator that lag
in relation to sound and attitude changes must be expected and
understood. Chasing the airspeed indicator is a common student
fault. Even worse is not recognizing that the VSI (vertical speed
indicator) takes about 12 seconds before giving accurate indications
unless the control movements are exceptionally smooth. Starting
the trim from a known position and keeping track of its movements
in various flight configurations makes possible rapid/correct
trim pressure corrections.
--Practice of the right kind makes perfect
--Don't begin a maneuver until the aircraft is in stabilized flight.
--Start over if a maneuver starts wrong.
--Don't practice making mistakes.
--Self-evaluation is a part of the process
--Be willing to seek advice.
Holding
Headings
A pilot (not a student) is expected to hold a heading. The
PTS allows a + 10 degree or 20 degree range. It is a mistake to
be accepting of this range. Successful flying is most dependent
upon acquiring and holding a heading, not a range of headings.
Success in holding a heading is dependent upon a pilot's ability
to 'hold' the yoke in one position while attention and movement
is directed elsewhere. It doesn't come easily or cheaply but it
is there to be achieved. Rudder alone will do the best job.
Turning to a heading is another much sought skill. The variables
in a turn far exceed those in level flight headings. The turn
has the angle of the bank, anticipation of yoke pressures, and
airspeed as a factors. The quality of the turn is measured by
the pilot's ability to determine when to begin rolling the wings
level, when to stop at level and most of all how to keep it there
during the transition. For every degree of bank and airspeed we
must learn what to do and when to do it.
Other opinions to the contrary, the thirty-degree bank is the
safest and most controllable bank. The turn can be cleared and
completed in a minimal time. The established bank is quite stable
in comparison with others. Making a standard bank procedure develops
a sense of turn time and direction that is easily adapted to airport
patterns. This stability can be demonstrated by entering a 30-degree
bank, putting in about 1/2 turn of trim to hold the nose and then
holding the bank with light rudder. It will hold both bank and
altitude better than in any other banked condition.
The preferred method of recovering from a bank to a selected heading
is to begin recover at half the number of degrees in the bank.
A thirty degree bank's recovery will begin at 15 degrees before
the desired heading. These markings are easily observed on the
heading indicator. With some adjustment in the recovery rate this
method will work for all banks. In the real instrument (IFR) world
the standard-rate turn (3-degrees per second) recovery can be
done quite quickly without regard to any rule.
A pilot should not assume that yawing tendencies caused by
attitude, P-factor, gyro effect and lift are limited to tail draggers.
Any correctly flown single engine propeller driven aircraft will
respond to these factors and effects. Just how much response is
noticeable depends on airspeed and power applications. The left
turning tendencies in airplanes is a part of their nature. The
pilot must learn to anticipate changes in these effects in use
of the right rudder. Reaction will always be too late if not too
little. Try holding the nose straight with the rudder momentarily
while rolling into a 30-degree bank. to do this you must keep
your eyes outside the cockpit and watch the nose. Establish the
bank and hold it with the ailerons.
Propwash
The air flow from a propeller swirls like a corkscrew around
the fuselage of the plane. It curls across one wing differently
than the other and into the vertical stabilizer and rudder from
only one side unless there is one below the fuselage. In a C-150
the left wing will have a higher angle of attack than the right.
Higher angles of attack create drag. The propwash hits the left
side of the vertical tail components. Because of propwash the
rudder is the first on your controls to become effective. In low
speed high power situations your rudder is the most effective
control you have. Both of these effects contribute to the left
turning tendency of an aircraft. The pilot must counter these
effects by anticipating use of the right rudder.
Propeller
The propeller has 80% efficiency. This efficiency exists only
at the designed cruise speed, which is often faster than the L/D
and fuel efficiency speed. A constant speed propeller is most
efficient as RPM is at or slightly below manifold pressure. A
propeller is most efficient if the leading edge is rounded smoothly
and the trailing edge is squared.
P-factor
The arc that a propeller makes can be considered as a variable
pitch disk. In a vertical plane to the horizontal the pitch of
the entire disk is the same and it pulls equally side to side
and top to bottom. Pitching the nose up causes the blade pitch
angle on the left descending blade to increase and the rising
blade on the right to decrease. The descending blade takes a larger
cut than the rising blade. It is working harder and exerts more
pull on the right side. The net effect of this is to turn the
aircraft to the left. Some aircraft engine installations point
the engine slightly to the right. The right thrust effect is used
to offset the p-factor of the descending blade. Usually the pilot
must anticipate P-factor with applications of right rudder.
Torque
I have always demonstrated torque using a rubber-band powered
model while using only the fuselage with no wings or tail. Wind
up the propeller and let it go. As the rubber-band unwinds the
propeller turns in one direction and the fuselage turns in the
other. On the ground the landing gear prevents your airplane's
fuselage from turning but it does cause the left tire to exert
more ground pressure than the right. This causes a left-turning
tendency. Additionally the left wing can be set (twisted) to provide
the additional lift that counters the torque effect of the propeller
while in the air. This wash-in amount is most effective at cruise.
In low-speed-high-power situations the pilot must add right rudder.
The gyroscopic propeller
Pitching of the nose causes yaw, and yawing of the nose causes
pitching. As mentioned before the propeller is a spinning disk
and has all the effects of the toy gyroscope you see in stores.
Just by pitching up you can cause the plane to yaw to the left.
Yawing the aircraft back and forth with the rudder will cause
the nose to vary in pitch.
Level Dynamics
When a pilot has his aircraft flying so that the amount of
propeller thrust is equal to the drag and the wing lift equals
the weight plus the negative lift of the tail surfaces he is in
level flight. The weight will always be focused to the center
of the earth. Up to the wing's critical angle of attack an aircraft
and power available will be able to maintain level flight over
a wide range of speeds. When the aircraft is flying slowly drag
is mostly induced drag. At high speeds drag is mostly parasitic
drag.
Enter successive 20, 30 or 45 degree banked turns. Reduce power during the turn. Hold altitude. Stabilize turn at reduced power with trim. Note increased rate of turn at lower airspeed. A one-third reduction in airspeed will reduce your 30-degree bank turn radius by over 50%.
Leveling
Off from Climb
An old saying among pilots is, "How long does it take
a student pilot to level off?" Thirty-five hours is the answer.
It should not take that long if the instructor is on the ball.
The student should know for leveling off from a climb at Vy will
require a certain amount of anticipation, a certain amount of
trim, a certain amount of acceleration, changing amounts of yoke
pressure, a power adjustment, changing sounds and some fine tuning.
The trick is to put the aircraft into the desired attitude and
leave/keep it there.
Demonstrate how pushing forward on the yoke will both lower the
nose and level the bottom of the wing's surface with the distant
horizon. Have the student perform. Have the student watch the
wing and hold it locked level with his arm against the door. Have
him note the pressure required. Have him swing his eyes to measure
the space between the nose and the horizon. Have him touch the
bottom most button on the trim wheel and move it full up while
keeping the nose in position. Have him note the gradual change
in pressure as the plane accelerates. Power should be reduced
when reaching 85 kts. Instructor might make any fine changes needed.
If the student needs to search for level flight and is carrying
control pressure then he's doing something wrong.
As you reach a desired altitude sight on the horizon under the left wing and move the yoke forward until the wing tip is level. Immediately bring your vision to the nose and hold the yoke so that the nose does not change position relatively to the horizon. Trim to relive pressure but according to the final trim condition desired. If you continue to adjust the trim while the aircraft is still accelerating you will create problems to yourself. Let the aircraft reach its cruise speed (85 kts) and power set before making final trim adjustments.
Level Cruise
#2
By going high and then diving to acquire cruise speed you
can get to speed faster. Some aircraft actually get on a 'step'
like a speed boat and will maintain a higher than normal speed
until the condition is disrupted. The reason for not reducing
the power initially to 2450 is that some deceleration occurs during
leveling off. This causes a 100 decrease in RPM.
Level Cruise
#3
The actual reason for having the student to look at the bottom
side of the wing for the nose level attitude is because the student
does not yet know where to look over the nose. The use of the
wing can be substituted by a
marker on the windshield once level for the particular person
has been determined. Each persons 'level' will be slightly different.
Level flight is established and maintained by positioning the
nose. Repetition in positioning the nose is the best way for a
student to learn where level is. The more often you trim for hands
off level the better able you will be able to discern just where
level is. With constant power there is one point on the windshield
that keeps the plane level, every rate climb or descent has a
specific position for placement of that point based on constant
airspeed. Airspeed is a relatively coarse way of nose adjustment.
It takes & makes a proficient pilot who uses the nose position
for level flight. The pilot who trims for his climb and descent
airspeeds soon develops a set of constants for the aircraft. With
repetitive practice the pilot will learn to feel, hear, and SEE
just where a particular configuration and attitude will position
the nose.
Unable
to fly level
After you have been flying a while either with the instructor
or solo a common phenomenon seems to occur where the new pilot
is suddenly having difficulty in leveling off. This is normal.
As we have trained and practiced we have developed along with
the procedures for leveling a set of references. We may have started
with the wing on the horizon and gradually been able to reference
the nose to the horizon. Now, it doesn't seem to work. We may
oscillate in altitude, airspeed and trim for several minutes and
still not get it right. It is going to happen.
The reason it this occurs may be due to one factor or a combination
of factors. If the weather changes so that your usually clear
horizon is blocked by haze or cloud formations you have lost an
essential reference. Flying in mountains where the horizon cuts
through the mountains can be a causal factor. Perhaps due to a
distraction you forget to trim. Power control can cause the aircraft
to fail to accelerate or to exceed cruise speed. Any one of these
or a combination can cause leveling off problems. You might practice
making deliberate errors in your leveling off procedure to ascertain
the corrective procedure that works for you.
Most of the small movements evade detection of the eye but are
sensed subconsciously by the peripheral vision, dangerously so.
In certain pattern turn conditions the peripheral vision can deceive
your brain as to the true attitude of the nose.
On making
turns
In the very beginning of flight instruction and any proficiency
check I review the four basics. Of these, the making of turns
require the most attention. A properly performed turn is a thing
of beauty with just the right amount of aileron, rudder and pitch.
Just the other day, I had a student reviewing for her second solo
in the pattern. She had what I call an 'a-ha' experience. She
had performed the cross wind turn from entry to rollout at exactly
65 knots in the C-150. Such a turn is not easy. The use of rudder
must be anticipated along with feather-light pitch pressures.
The aileron into the roll in and out must be smooth and blended
with the use of rudder. I want my students to use 30-degree banks,
no more, no less. Such a bank is unique in that when reached and
held there the yoke will be parallel to the cockpit panel just
as in level flight. the 30-degree bank is very stable and can
be held there with light rudder pressures. There is only .15 G
difference between level and the bank G-forces. The 30-degree
bank feels good when done right and held there.
There are distinct differences between left and right 30-degree
banked turns. In a Vy climb a turn to the left may well not require
any additional rudder pressure except when rolling out. The entry
into a right bank from a Vy climb will require leading with the
rudder, holding it into the turn and relaxing it during the roll-out.
These uses of the rudder are not intuitive and exist to a slight
degree even in level and descending flight.
Practice doing the Dutch roll will sensitize the student to the
sensations of a slip, skid, and coordinated flight by creating
the discomfort of uncoordinated flight. The rigging of the aircraft
is a variable factor that accounts for the need of pilots to adjust
to each aircraft. The making of 30-degree banks is useful as a
maximum limit in the pattern because it makes the turn quickly
into the cleared area. A more shallow bank is useful if a higher
rate of climb is required as in making a 270 departure. ATC prefers
the 30-degree bank to the 20-degree bank because it is less likely
to be confused with a wing wobble. 30-degree banks can be checked
with both the attitude indicator and the Cessna wing strut being
parallel to the ground or horizon.
In making turns there are two criteria that are used around the
pitch axis. In level flight it is the altitude and in climbs and
descents it is airspeed or rate of descent. The indicator in both
cases is the nose and sound. 30-degree banks do not require much
pressure but the application an removal of that pressure must
be done in anticipation of what is going to be happening.
On rolling into the turn you apply pressure with the forefinger and hold it until beginning to roll out. At this point you apply thumb pressure because the increased lift in level flight always causes a pitch-up unless anticipating counter pressure is applied. The usual rule for rolling -out on a heading is to begin at half-the-angle-of-bank. Students should be encouraged to watch the nose during turns with only quick glances at the heading indicator for the lead-in heading used for rollout. The final heading should be initially acquired by watching the nose. Any fixation on the heading indicator prior to or after roll-out will generate wing wobble. Precise turns are a matter of consistency in the roll-in and the rollout.
Why turns
turn
A turn is a combination of several aerodynamic factors. Individually
each factor has both positive effect and negative effect. Beginning
with the ailerons the inside aileron goes up and decreases lift
that lowers the wing while the outside aileron goes down and increases
the lift that raises the outside wing. We now have roll. Along
with raising the wing the outside aileron just by increasing the
lift also creates drag. Parasitic drag that is. This drag is a
negative that tends to swing the nose away from the turn. This
is yaw... Adverse yaw, that is. The combination of roll and drag
is called coupling. With roll you get yaw. The speed or rate of
your roll entry, by affecting the relative winds of the two wings,
causes additional but slight adverse yaw.
Without coordinating rudder to counter any adverse yaw the aircraft
is in a slip. The lower wing is faster and moving forward and
rising with the increased lift. The relative wind weakly moves
the vertical stabilizer away from the turn effectively moving
the nose into the turn and reducing the slip.
Coordinated rudder solves all the dynamic equations of the turn.
It eliminates adverse yaw and all the forces that reduce roll
effectiveness. the rudder must be applied or even anticipated
at the beginning of the roll and then pressure reduced once the
aileron deflection is reduced. The roll-out to heading reverses
the roll-in process. Turns are more enjoyable when the proper
rudder forces are applied.
Level Turn
Dynamics
A banked aircraft transfers some of the available wing lift
away from the vertical into a turning force. It is this transfer
of lift that makes it necessary for the pilot to increase the
wing's angle of attack to obtain the lift required for maintaining
a constant altitude. In this bank there is an apparent increase
in weight caused by the horizontal centrifugal forces of the banked
turn. At a 60-degree level altitude bank the weight of everything
is doubled. (2 G's) A 30-degree bank has an effective weight increase
of .15 Gs.
Since the most likely C-150 mid-air will come from a faster aircraft
from the rear quarter, always look beyond 90 degrees when clearing
but any aircraft above the horizon will pass overhead. Any following
aircraft should pass to the right, initiate clearing turns to
the left. There is nothing wrong with raising the wing for clearing.
The instinctive desire to see around the wing in the direction
of the turn is both dangerous and inefficient. You can't really
see and you decrease your ability to hold both bank and airspeed.
Keep your eyes on the nose and horizon during a turn. Don't turn
into an area you have not cleared. Do not pull back on the yoke
to recover from a turn or bank, use the ailerons.
Bank recovery
to a heading
Lead your recovery from a left bank by applying right rudder.
Lead your heading recovery by 10 degrees in a 20 degree bank,
15 degrees in a 30 degree bank and 22 degrees in a 45 degree bank.
Every recovery from a bank also requires that some forward pressure
be applied to prevent the 'pop-up' airspeed loss that will occur
as the wings acquire added vertical lift when leveled.
Level
Turns
The turn is the only of the four basic maneuvers that exists
in conjunction with the other three. The level turn is a balanced
condition, as with level flight, where the lift equals the aircraft
weight. With constant power the airspeed and angle of attack are
controlled with the elevator. Some airspeed is lost during the
turn due to an increase in pitch. The rudder keeps the tail behind
the nose. The quality of the turn is a blend of yaw, roll, pitch
and power. The blend is changed as the angle of the turn increase
or if it occurs as level, climb or descent. A climbing or descending
bank requires a different blending of these factors.
Elevator controls pitch. Elevator trim is for removing control
pressures when a prolonged flight condition or attitude is to
be maintained. Entering a 30 degree bank requires slightly forward
yoke input on the elevator with the thumb. This prevents excessive
loss of airspeed. On reaching 30 degrees a slight back pressure
with the finger will give the pitch needed to maintain altitude.
Recovery from the bank requires slight forward pressure with the
thumb again. These finger applications are more pressures than
movement. If the turn is to the right, rudder pressure precedes
aileron movement. Recovery from a left turn requires that right
rudder pressure precede aileron movement.
The only control difference between the left and right bank is
the anticipation and lead required on the right rudder. You lead
the right turn with right rudder perceptibly before you need to
with the left rudder in a left turn. Again this is because of
aerodynamic factors . Likewise, the recovery from the left bank
requires anticipation and leading with the right rudder before
leveling off. In this instance forward pressure is required to
prevent the 'pop-up' from causing an altitude gain when leveling
off. The steeper the bank the greater the need for knowing about
the amount of anticipation and firm forward pressure required.
The design of most light aircraft gives a stable 30 degree bank
hands off with just a little nose up trim. The aircraft will tend
to level off from any bank less than 30 and become steeper from
any bank more than 30. At 30 degrees the G-force is +1.15, at
20 degrees the G-force is 1.06, at 45 degrees you get +1.41 G,
at 60 degrees the G force is +2.0. Aileron must be held into the
bank at less than 30 degrees, against the bank at more than 30
degrees and neutral at 30 degrees. Any time the ailerons are not
neutral there is induced yaw which must be countered by rudder.
Adverse yaw ceases when ailerons are neutral.
A similar maneuver will work with most any G.A. plane but the
amount of trim will vary. A bank of less that 30 will cause the
aerodynamics of the plane cause it to want to level off. Yoke
must be held into the bank. A bank of more than 30 will cause
the plane to want to continue on over. The yoke must be held against
the bank to keep the bank from increasing.
Level
turn exercises (Instructor)
Select a flight course on a cardinal heading and toward a
prominent point on the horizon. Execute a series of left and right
30 degree banked turns of 90 degrees. The first turn should be
to the left. (Any passing traffic to your rear should be passing
to your right.) No turn should be initiated without visual clearing.
This clearing should include at least 30 degrees to your rear.
I recommend saying, "Clear left, turn left." Once the
turn has been cleared and the 90 degree reference point selected
under the wing the pilot's eyes should be over the nose of the
aircraft. Since we are turning left P-factor will aid in coordinating
the ball position so little left rudder will be required. Once
the 30 degree of bank has been attained the yoke must be neutralized
as to bank. (The aircraft in a 30 degree bank is relatively stable.
An aircraft in less than a 30 degree bank wants to level out and
must be held into the bank by yoke pressure. An aircraft in more
than a 30 degree bank wants to increase the bank and you pressure
must be held against the bank. This is part of the VFR to IFR
transition problem.) The C-150 wing strut parallel to the ground
makes a 30 degree angle bank. Yoke pressure will be slightly forward
initiating the bank; slightly back as the 30 degree bank is reached
and slightly forward to prevent 'pop up' as the aircraft is leveled
off. (The automotive practice of leaning forward, then tilting
and turning the head during a turn will cause problems in holding
altitude.) As the turn progresses toward the 90 degree point the
90 degree reference will come into view. The leveling off from
a left turn requires some anticipation of the pilot in leading
the yoke pressure out of the bank with light right rudder pressure.
Forward yoke pressure is applied just as wings level occurs.
The turn to the right requires some slightly different techniques.
Clearing and selecting the 90 degree point is followed by, "Clear
right, turn right." Initial yoke movement into the bank is
preceded by right rudder since there is no P-factor assistance.
Very little left rudder is required leveling off from a right
turn. All yoke pressures and movement are essentially the same.
(If a student increases the bank instead of leveling off it is
probably because they are using and misinterpreting the attitude
indicator instead of watching the horizon.)
The first turns should use visual references then use the heading
indicator. (I often reset the heading indicator to get the visual
points to correspond to cardinal headings.) Leveling off on a
given heading requires only that the leveling pressures preceded
the selected heading by a number of degrees half the angle of
bank. A 30 degree bank should begin leveling 15 degrees before
the selected heading.
The accuracy of the visual reference turns can be demonstrated
by having the student note the present heading and a 90 degree
visual reference point. Make the turn while the heading indicator
is covered; checking only when level. It is important to practice
these turns only a few times during each flight. Don't beat on
a particular skill for too long. Level turns have skills related
to both climbing and descending turns. It is important that the
instructor utilize the instructional time and flight segments
in the most efficient manner. A good way to provide a break between
skill practice is to survey the area for check and reference points.
One of the very first exercises I do with a new student is to
justify my insistence on 30 degree banks in all VFR maneuvers.
In the C-150, after clearing, I have the student enter and hold
a 30 degree bank and give about a half turn of nose up trim, then
he is to let go of the yoke and fly only with rudder.
Climbing
Left Turns
All turns that are going to exceed the angular range of windshield
vision should be preceded by "clear R/L, Turn R/L" Failure
to clear will fail any flight test.
Since there is increased P-factor present in a climbing left turn,
some right rudder might be required throughout the turn to keep
the ball centered.. Even more right rudder will be required when
leveling off. The aircraft will tend to lose some indicated airspeed
when all turns are initiated. A slight, almost imperceptible forward
pressure with the thumb will prevent this indicated speed loss.
As soon as the 30 degree bank is reached the thumb pressure is
removed and replaced by sufficient one finger pressure to maintain
both bank and airspeed.
In addition to P-factor that exists in a climb, in a climbing
turn we introduce yaw. Yaw in a turn is caused by drag. Drag,
in turn, is produced by a higher angle of attack. The high wing
in a turn has more yaw and more induced drag and a higher angle
of attack because of the down aileron. The fact that it is moving
faster is a minor but existing parasitic drag factor. It is the
initial induced drag of the aileron's greater deflection when
rolling in and out of banks that increases the need for more rudder
Climbing
Right Turns
Right rudder pressure is being held in the climb due to P-factor.
Even more is now required to initiate the right turn. Anticipate
the need to lead with right rudder in making right turns. Yoke
pressures and anticipation is much the same as with left turns.
Recovery from the bank requires only that the right rudder pressure
be relaxed and then reset for P-factor to climb on heading.
Steep Turns
At some point during the first four flights steep turns should
be demonstrated by the instructor. You should use a prominent
visual reference on the nose at a cardinal altitude. While the
PTS (Practical Test Standards) requires only one 360 degree turn,
the most instructive steep turn consists of two full 360 degree
turns, 45 degrees of bank, a constant altitude, and cruise power.
The bank entry to the 45 degree steep turn should be smooth and
rapid. Initially check the angle of bank on the horizon against
the attitude indicator. Once the angle has been achieved concentrate
on the horizon and its angle. Variations of five degrees of bank
may be used to control altitude. The new PTS requires only one
360 degree turn with recovery near heading.
After clearing, enter the steep turn smoothly and rapidly, lead
with right rudder if to the right. Sight on the horizon and anticipate
the loss of lift with a locked elbow on the door and sufficient
back pressure to prevent a loss of altitude. Angle of bank may
be varied from 45 + 5 degrees to adjust altitude. Using the elevator
to adjust altitude gives only an illusion of change. Actually
the turn is being made steeper with a resulting loss of altitude,
increase in G-forces, airspeed and angle of attack.
Steep turns are precision maneuvers flown as a confidence builder.
The vertical lift lost by the steep bank must be replaced by increasing
the angle of attack by applying back pressure. The seemingly great
pressure required is because of the increase in G force due to
the bank. The critical angle of attack of the wing remains the
same but due to the increase in weight (G-force) the stall occurs
at a much higher speed. (A stall in this situation is called an
accelerated stall because of the higher speed.) Rudder is used
to compensate for drag /adverse yaw from the raised wing. Once
in the turn, the raised wing will travel faster and provide more
lift. To compensate for this lift caused overbanking tendency
the ailerons must be held against the bank.
The steep turn, properly performed as to bank and altitude, will,
as the second 360 degrees of turn are performed, come in contact
with the wake turbulence of the previous 360 degree turn. This
second 360 is no longer required by the PTS (Practical Test Standards)
but it is the best way to self check performance of the maneuver.
Encountering the wake will cause the wings to rock and maintaining
altitude typically becomes a problem. The initial surprise seems
to be the cause. The student will instinctively relax pressure
when it should be held or increased. If more than 100 feet is
lost the process should be started over from the beginning. Since
the bank is 45 degrees the leveling off should begin about 22
degrees early. A very positive forward pressure must be applied
to prevent a pop-up increase in altitude. The turns should be
performed both left and right but perhaps at different time since
they may cause student distress.
There are two distinct ways the steep turn may be performed, with
or without trim. The unexpectedly high yoke pressures required
to hold both the bank and the altitude is difficult for students
but very instructive. They should learn to press their arm against
the door to lock the pressure and position. The second way is
easier but requires some timing. Airline instructors do not allow
the use of trim. At the moment the 45 degree bank is attained,
give the trim wheel two quick full turns down. This will release
almost all of the pressure required to hold altitude. Now most
of attention can be devoted to bank angle and the slight changes
needed for altitude. The yoke release often caused by the surprise
of wake turbulence will be compensated for by the trim setting.
However, when leveling off the trim must be removed very quickly
before it aggravates the typical pop-up pressures of leveling
off.
First: go as quickly into the bank to 45 as you can in both methods.
Easy way: Using the tip of your right forefinger quickly make
two top to bottom of the trim wheel. Now a light touch will keep
you in the bank and at the same altitude. Lead your recovery by
22 degrees and again quickly remove the two turns of trim with
your finger tip. Do not pinch the trim wheel.
After clearing turns, choose a reference point or direction over the nose before beginning. You will start your rollout when that reference point first enters the side of the windshield. This gives you a way to keep your head outside the cockpit during the maneuver.
Steep turns can be done using trim or without trim. Learning without the trim is more difficult because of the required control pressures. The steep turn of the PTS requires that airspeed be kept within ten-knots. At cruise power this should not be a problem if some extra power is added once into the turn. when there is no visual horizon it may be necessary to use the attitude indicator. You should practice using both the visual horizon and the AI. At constant power the horizons (actual and AI)in position, you will be holding altitude. You do want to practice your recoveries so as to come out on a predetermined heading.
Flying from the low seat in a turn will commonly cause a pilot to climb. Flying from the high seat will commonly cause a pilot to descend. Tandem seat cockpits do not have this problem. You will have a point on the windshield at eye level that is offset from the aircraft centerline by the same distance as your head. By marking this spot in some way you can make your left and right turns by keeping the mark on the horizon. Some adjustment of the mark is to be expected for different flights and aircraft weights. Your mark will always work for you.
A steep turn in VFR can be referenced to this windshield mark. Just keep the mark on the horizon. Use the center dot on the attitude indicator for IFR turns. The VSI is an early indicator of attitude change. Watch it. Sound changes are early warning signals to check the VSI. Most turn corrections tend to be in excess of what is really required. One technique to use when you make an attitude correction is to immediately take half of it off. This is one way to reduce the tendency to over react.
If you are flying a plane where you can push the throttle all the way in, I suggest that you find out how fast the plane will maintain a steep turn at full throttle. Then, find the power setting that will give you that speed in level flight and use that for your entry speed and power setting. Roll into the turn aggressively and put the power in as you go through 30 degrees of bank.
Second
Way:
Go as quickly into the bank as you can. Lock your arm and elbow
against the cabin door. Listen to the sounds! As one of the others
advised anticipation is the name of the game. Watch the VSI with
quick glances. Watch the nose vs. the horizon the same way. You
will probably overreact to VSI movement so when you do react release
half of the reaction and you will be about right.
The new PTS now requires only a 360 but I suggest that you do
a 720. On the second time around you will be in contact with your
own wake turbulence if you have done the first 360 well. The wake
turbulence is a way to check your performance. Don't do to many
steep turns at one time.
Trimming makes the steep turn easier but it bypasses the instructional
purpose of doing the steep turn. The purpose of the steep turn
is to develop the awareness and anticipation of the control forces
and attitudes required. Heavy control forces are designed into
the performance of the aircraft when and where destructive G-loads
exist. If trim is allowed in steep turns to show the required
attitude, then just as many turns should be made without trim
to show the required control pressures to attain and maintain
that attitude.
A common error related to steep turns is what the pilot does when
a loss of altitude occurs. The initial perception is that the
loss is due to insufficient back pressure on the yoke. This may
well be the case but the recovery of this lost altitude by only
increasing the back pressure is not the solution. The increase
in back pressure alone will tighten the turn by increasing the
angle of bank which will lead to a further loss of altitude. The
geometry of the hand, arm and yoke cause this. Any increase in
back pressure must be accompanied by a decrease in bank angle
at the same time. Often loss of altitude can be corrected by just
removing some of the bank. It is this incorrect recovery from
a banked turn that leads the graveyard spiral and spatial disorientation.
Get the wings level, recover altitude and start the steep turn
again. The essential is that the angle of bank be held so that
no changes in back pressure are required.
Trimming during steep turns can be dangerous. The potential is
there if situational awareness is dimmed. Any descent can become
a high speed spiral at excessive G-load. The steep bank should
never be entered at speeds over Va. Higher speeds than Va will
over stress the aircraft. A steep turn can only be recovered by
leveling the wings. Ailerons will still be effective. Rolling
out of the trimmed bank without removing the trim can cause a
low-speed unusual attitude. Pulling back on the yoke to hold altitude
or prevent a spiral dive is more likely to increase the bank and
make the spiral more steep. Avoid such trimming at night, IFR,
or in low visual conditions.
I recently took a flight check ride where the airspeed was decreased to 80 knots with power at 2200 rpm. I was then told that I was to enter into a steep turn of 45-degrees while adding power into the turn to maintain the 80 knots throughout the turn. I have always considered relatively low speed steep turns as something to be avoided. I did not do well. I had never tried to perform in that manner. I believe it can be done with some difficulty by anticipating the power application. I normally do steep turns at cruise power. More about this later.
Steep
Turns (Basic)
Pressures keep changing in the steep turn your coordinated
aileron and rudder, back pressure, all changing to opposite aileron
and reduced backpressure when established at a constant airspeed.
If you have gone smoothly to slightly over 30 degrees and held
some back-pressure the normal overbanking tendency of the aircraft
will wind up at the desired 46-degree angle. It will take opposite
aileron to keep it there.
The plus/minus ten-knot speed allowance can be set up either entering the turn or after the turn is established. Enter the turn and add some power in anticipation of a loss of speed. Another way is to wait until the turn is established and then add a predetermined amount of power to stay within the allowance.
The vertical speed indicator is the rabbit to be watched. The slightest movement up or down is a warning of altitude changes soon to follow. The VSI is a more important instrument than the altimeter is during a steep turn.
The recovery from the steep turn is based upon the half-angle recovery method but must be followed by abrupt forward yoke to prevent a sudden increase in altitude. Watch the VSI and lock your elbow.
Steep
turns (Complex)
A method is to use additional power to maintain altitude.
Determine in flight the descent rate at a given bank angle when
not maintaining altitude.
Add 1" of MP for every 100fpm of sink to maintain altitude.
Technique works only from something less than cruise speed. A good entry speed would be a holding speed or approach speed. Add the throttle smoothly when rolling in the bank and reduce throttle when rolling out.
VSI
in Slow Flight and Steep Turns
Slow flight and steep turns are areas where a pilot would
do well to pay more attention to the VSI. The VSI is a very precursor
of altitude loss. By watching the VSI a pilot will be able to
anticipate the need for power sufficient to prevent any descent.
In slow flight every change in power should be accompanied by
proportionate rudder pressure. In the steep turn you can use the
VSI to get the yoke pressure back or forward to prevent altitude
excursions.
One instructor suggests using a small isosceles triangle on the
windshield as an instructional aid. 45degree; 45degree; left turn
right turn edge.
Downwind
Turn
The downwind turn problem is not one of physics so much as
psychological. The sensory reaction to ground proximity, ground
speed and flight position is likely to create a situation conducive
to instinctive reaction rather than considered anticipation.
Impossible
Turn
Popular wisdom is that a pilot should never turn back to a runway on takeoff. An even older wise axiom is, Never say Never". Studies of the most likely to succeed turn back to the runway is the one that is into the wind at 45-degrees. The requisites are that the turn be coordinated, smooth and on airspeed.
This maneuver must be practiced at altitude until performance
meets the highest standards of angle, airspeed and smoothness.
Lack of coordination will cause a stall and spin entry. Only practice
of the right kind will prepare a pilot for low level performance.
The Vy climb speed used for takeoff is very nearly the same as
the standard approach speed and the 45-degree steep turn stall
speed. The stall margin requires strict attention to the performance
of the turn and foregoing ground proximity awareness. Success
means survival. You will not be able to get back to where you
lifted off. You
may be able to reach the departure end of the original runway. This is better considering you will have a tailwind. Anything over a ten-knot tail wind would negate making the 'impossible turn' possible. Crosswinds, crosswind runways, and local factors can change your options.
Clearing
turns
The most basic 'clearing turn' is with the neck prior to starting
the engine and YELLING clear.
The next 'clearing turn' occurs when you make a 360 prior to taking the runway or at least facing the final approach course so as to clear both base legs.
The training 'clearing turn' during climb out that I use is practicing Dutch rolls. This clears the airspace covered by the raised nose.
The 'clearing turn' I use prior to airwork can either be a left 360 or a left 90 followed by a right 90. The initial turn is always to the left since passing traffic should pass on the right.
Found a CFI did not know what a course reversal was.I usually initiate course reversals with a left 90 and then a right 270 for the same reason stated above. The best time to look for traffic in a Cessna is when the wing is raised away from the turn. The course reversal is another good way to make the 'clearing turn'.
I have found that the safest 'clear area' is to avoid flying at thousands and five-hundreds when within 3000' AGL. My local safe area is to fly below Class B shelves at 2700 AGL.
Graveyard
Spiral (Hood)
This is a slow turn that will gradually increase in bank angle
because of the lift differential between the inboard and outboard
wing. The pilot does not need to apply any input. Bank angle increases
result in the nose dropping and speed increasing.
An aircraft can be expected to have the wing fail upward and
forward under the positive-G overstress of this situation.
However, if the speed is greater than 15% of the Vne the failure
may be downward and aft. Flutter causes this type of
failure.
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