With the SPORTS PILOT CERTIFICATE looming on the horizon I Larry, will try to cram some knowledge into you knuckleheads. Please remember that Larry was not the sharpest tool in the shed. Larry is hoping to explain things in his simple lame brain way. It is hoped that you fine gentlemen and ladies would be able to pass the Recreational Pilots Written Exam after understanding these fine examples of learning.

To describe an airplane in words we must be able to identify the motions of the fixedwing aircraft. There are three axes which are all perpendicular to each other.

LONGITUDINAL AXIS- also called the ROLL AXIS extends lengthwise through the fuselage. The AILERONS cause rotation about the longitudinal axis. LATERAL AXIS- extends across the aircraft from wing tip to wing tip. This axis deals with PITCH and the airplane's ELEVATOR controls rotation around this axis. VERTICAL AXIS- extends vertically through the center of gravity. Movement of the RUDDER causes rotation around this axis. Q. The three axes of an aircraft intersect at the...CENTER OF GRAVITY Many of this chapter members have heard it stated that $Money$ makes an airplane fly. Not true. It is the relationship between pressure and velocity in the air flowing over the wing. Bernoulli’s Principle tells us that as air flows over an airfoil, the pressure will decrease as the velocity increases. Also the pressure will increase as the velocity decreases. Most wings have some type of curved or camber shape on the top half of the wing. When the air flowing over the top of the wing speeds up, its pressure drops and air above the wing is pulled down to fill this low pressure. Since for every action there is an equal and opposite reaction, the force with which the wing pulls the air down is exactly balanced by a force which pulls the wing up. The same force that pushes the air away pushes the wing up. The result of the air being pulled down to the top of the wing and pushed away from the bottom of the wing causes the air
flowing over the wing to be forced down at an angle called the DOWNWASH angle. The weight of the air forced down is exactly the same as the lift causing the airplane to be forced up. This is determined by five factors:
-the cross-sectional shape of the airfoil (big or small camber or equal (Symmetricalsame on top as the bottom)
-the surface area of the airfoil (how long & wide the wings are)
-the angle the air strikes the airfoil (called the angle of attack)
-the speed of the air moving over the airfoil (more speed more lift)
-the density of the air (warm air is less dense- it has less molecules than in a standard (59 degrees F) unit of air. Cold air is more dense because of more molecules per standard unit of air.

Airfoil terms you need to know:
CHORD LINE- A line that passes through an airfoil from the leading edge to the trailing edge.
CENTER OF PRESSURE- the point on the chord line of an airfoil at which all the
AERODYNAMIC FORCES are thought to be concentrated.
RELATIVE WIND- the direction which the wind is moving when it reaches the airfoil.
ANGLE OF ATTACK- the angle between the chord line of an airfoil and the relative wind. The angle of attack varies in flight.
ANGLE OF INCIDENCE- the angle between the chord line of an airfoil and the longitudinal
axis of the aircraft. This is set at the factory.
UPPER CAMBER- the contour of the top surface of an airfoil.
LOWER CAMBER- the contour of the bottom surface of an airfoil.
MEAN CAMBER- a line from the leading edge to the trailing edge that is equidistant at
all points from the upper and lower camber.

Q? The angle between the chord line of the wing and the longitudinal axis of the aircraft is known as... ANGLE OF INCIDENCE.
Q? The angle between the chord line of an airfoil and the relative wind is known as the angle of...ATTACK
Q? A line drawn from the leading edge to the trailing edge of an airfoil and equidistant at all points is called the ...MEAN CAMBER LINE.
Well I am sure the noodle is hurting so we will stop here until next month. There are 60 questions on the RECREATIONAL PILOT EXAM and it is my hope to review the areas cover by this exam. Soitenly.

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