Glossary of Terms
41
• Ailerons: Each side of this airplane has a hinged
control surface (aileron), located on the trailing edge of
the wing. Move the aileron stick on the transmitter left,
the left aileron moves up and the right aileron moves
down. Moving the left aileron up causes more drag and
less lift, causing the left wing to drop down. When the
right aileron moves down, more lift is created, causing
the right wing to rise. This interaction causes the
airplane to turn or roll to the left. Perform the opposite
actions, and the airplane will roll to the right..
• Clevis: The clevis connects the wire end of the pushrod
to the control horn of the control surface. A small clip,
the clevis has fine threads so that you can adjust the
length of the pushrod.
• Control Horn: This arm connects the control surface to
the clevis and pushrod.
• Dihedral: The degree of angle (V-shaped bend) at which
the wings intersect the fuselage is called dihedral. More
dihedral gives an airplane more aerodynamic stability.
Some sailplanes and trainer planes with large dihedral
dispense with ailerons and use only the rudder to
control the roll and yaw.
• Elevator: The hinged control surface on the back of
the stabilizer that moves to control the airplane’s pitch
axis. Pulling the transmitter’s control stick toward the
bottom of the transmitter moves the elevator upward,
and the airplane begins to climb. Push the control stick
forward, and the airplane begins to dive.
• Fuselage: The main body of an airplane.
• Hinge: Flexible pieces used to connect the control
surface to the flying surface. All hinges must be glued
properly and securely to prevent the airplane from
crashing. (This has already been done for you on the
Alpha Advanced trainer.)
• Horizontal Stabilizer: The horizontal flying surface of
the tail gives the airplane stability while in flight.
• Leading Edge: The front of a flying surface.
• Main Landing Gear: The wheel and gear assembly the
airplane uses to land. It is attached to the bottom of the
fuselage.
• Nose Gear: The part of the landing gear that is attached
to the nose of the fuselage. The nose gear is usually
connected to the rudder servo to help you steer the
airplane on the ground.
• Pitch Axis: The horizontal plane on which the airplane’s
nose is raised or lowered. By moving the elevator,
you can raise the airplane’s nose above the pitch axis
(climb) or lower it below the pitch axis (dive).
• Pushrod: The rigid mechanism that transfers movement
from the servo to the control surface.
• Roll Axis: The horizontal plane on which the airplane’s
wings are raised or lowered. By adjusting the ailerons,
you can drop a wing tip below the roll axis and cause
the airplane to bank or roll.
• Rudder: The hinged control surface on the vertical
stabilizer that controls the airplane’s yaw. Moving
the rudder to the left causes the airplane to yaw left;
moving the rudder to the right causes it to yaw right.
• Servo: The servo transforms your ground commands
into physical adjustments of the airplane while it’s in
the air.
• Servo Output Arm: A removable arm or wheel that
connects the servo to the pushrod (also called servo
horn).
• Spinner: Term describing the nose cone that covers the
propeller hub.
• Threadlock: A liquid that solidifies; used to prevent
screws from loosening due to vibration.
• Torque Rods: Inserted into the ailerons, these rigid
wire rods run along the wing’s trailing edge, then bend
downward and connects to the pushrod.
• Vertical Stabilizer: The vertical flying surface of the tail
gives an airplane stability while in flight.
• Wheel Collar: The round retaining piece that anchors
wheels in place on the wheel axle.
• Wing: The lifting surface of an airplane.
• Yaw Axis: The vertical plane through which the
airplane’s nose rotates as it yaws to the left or to the
right. The rudder controls the yaw axis.
