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Angle of Attack (AOA)
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.

Oh, that right rudder
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.

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