Tension
the stress that resists a force that tends to pull something apart
Compression
the stress that resists a crushing force
Torsion
the stress that produce twisting
Shear
the stress that resists the force tending to cause one layer of a material to slide over an adjacent layer
Bending
a combination of compression and tension
Truss structure
uses struts and wire-based wings
Monocoque structure
the skin itself carries the structural loads which allow the aircraft to be built with a more streamlined shape
Semi-monocoque structure
the skin is fastened to a sub-structure or skeletal framework, which allows loads to be distributed between the structural components and the skin of the aircraft
Symmetrical airfoil
the curvature of the upper camber is the same as the curvature of the lower camber
Upwash
deflection of the oncoming airstream is upward and over the wing
Downwash
downward deflection of the airstream as it passes over the wing and past the trailing edge
Compression strut
compression members which separate the spars that may be either steel tubing or heavy wall aluminum alloy tubing
Wing Ribs
are the structural crosspieces that combine with spars and stringers to make up the framework of the wing
Wing spars
are the principal structural members of the wings that resist torsional and bending loads
Compression Ribs
have been specially strengthened to take compressive loads
Drag Wires
the wires that extend from the front spar to the rear spar and run diagonally from the inboard to the outboard that opposes any force that tends to drag against the wing and pull it backward
Anti-Drag Wires
the wires that run between the front and rear spar and run diagonally from outboard to inboard that oppose any force that tends to move the tip of the wing forward
Gusset
a thin mahogany plywood plate attached to two or more members to carry the stresses from one member to the other
Nose Rib/False Ribs
Prevents air loads from distorting the leading edge
Cantilever wing
internally braced wings not requiring external support
Chemical Milling
good for quickly removing large amounts of material
Electrochemical Milling
used for cutting complex shapes or deep grooves
Nacelles
are streamlined enclosures used primarily to house the engine and its components
Cowling
the detachable panels covering those areas into which access must be gained regularly, such as the engine and its accessories
Flutter
occurs when an out-of-balance condition causes a control surface to oscillate in the airstream, typically increasing in frequency and amplitude until the control surface fails catastrophically
Static Stability
the tendency of the airplane to return to its original position
Dynamic stability
concerned with the way the restorative forces act with regard to time
Positive Stability
the airplane will tend to return to its original position
Negative Stability
the airplane tends to not return to its original position
Neutral Stability
the airplane tends to not return to its original position, nor will tend to move further away
Roll
airplane movement at the longitudinal axes of rotation
Pitch
airplane movement at the lateral axes of rotation
Yaw
airplane movement at the vertical axes of rotation
Lateral
axes of stability when the airplane is rolling
Longitudinal
axes of stability when the airplane is pitching
Directional
axes of stability when the airplane is yawing
Ailerons
the primary flight control surfaces that move the aircraft about the longitudinal axis
Elevator
the primary flight control surface that moves the aircraft around the horizontal or lateral axis
Rudder
the primary control surface that causes an aircraft to yaw or more about the vertical axis
Stabilator
a combination of the horizontal stabilizer and elevator
Ruddervator
a combination of the rudder and elevator
Flaperon
a combination of the flap and aileron
Flaps
found in the inboard trailing edge of wings which extends the camber of the wing for greater lift and slower flight that allows control at low speeds for short field takeoffs and landings
Balance Tabs
a type of tab that is directly linked to the control surface which allows it to automatically move opposite to the control surface
Anti-balance/Anti-servo tab
a type of tab that moves along with the control surface which increases feel and effectiveness of primary control surface
Servo Tabs
located at the trailing edge of a primary flight control that assist or provide the force for moving a primary flight control
Spoilers
located at the upper and or trailing edge of the wing that decreases lift and can augment aileron function
Slats
located at the mid to outboard leading edge of the wing which extends the camber of the wing for greater lift and slower flight. It allows control at low speeds for short-field takeoffs and landings
Slots
located at the outer leading edge of the wing forward of ailerons which directs air over the upper surface of the wing during high angle attack or lowers the stall speed and provides control during slow flight
Leading edge flap
located at the inboard leading edge of the wing that extends the camber of the wing for greater lift and slower flight. It also allows control at low speeds for short field takeoffs and landings