aircraft structures and landing gears Flashcards
airfoils that move rapidly through the air, create lift
wings
plane with one wing
monoplane
plane with two wings
biplane
plane with three wings
triplane
formula of aspect ratio
span/chord
span greater than chord
high aspect ratio
chord greater than span
low aspect ratio
measure of how long and slender the wing appears from below
aspect ratio
wings of an aircraft can be attached to the fuselage where?
top, mid-fuselage, or at the bottom
wings attached at the bottom of the fuselage
low wing
advantage/s of low wing
- easy to refuel
- better visibility above at the sides of aircrafts
- better ground effect which increase lift and reduces drag when it’s nearer to the surface
disadvantage/s of low wing
low passenger visibility
attached at the mid portion of the fuselage
mid wing
used by military aircraft
mid wing
advantage/s of mid wing
- better rolling
- less interference drag
- allow to carry weapons
disadvantage/s of midwing
- occupies lot of useful fuselage volume
attached at the top of the fuselage
high wing
advantage/s of high wing
- better visibility
- lots of space for ground staff during maintenance
disadvantage/s of high wing
difficult to refuel
short, nearly vertical supports that are attached to the wings a great distance from the fuselage
jury struts
Strongest wing structure which attached directly to the fuselage and does not have any type of external stress bearing structure
full cantilever
Usually has one or two supporting wires or struts attached on each wing and fuselage.
semi cantilever
Typical of a biplane ( two wings placed one above the other ) with its struts and wires.
externally braced
may be straight or curved, or one edge may be straight and the other curved
trailing edge and leading edge
internal structure of wings are made up of
spars and stringers spanwise, and formers or bulkheads running chordwise (leading edge to trailing edge)
principal structural members of a wing
spars
support all distributed loads, as well as concentrated weights such as the fuselage, landing gear, and engines
spars
carries part of the loads imposed during flight
skin
transfers the stresses to the wing ribs
skin
in turn, transfer the loads to the wing spars
ribs
incorporates only one main spanwise or longitudinal member in its construction.
monospar
ribs or bulkheads supply the necessary contour or shape to the airfoil here
monospar
incorporates more than one main longitudinal member in its construction. To give the wing contour, ribs or bulkheads are often included.
multispar
wing construction uses two main longitudinal members with connecting bulkheads to furnish additional strength and to give contour to the wing.
box beam
two sections of a spar
top section and bottom section
what consists of top section
cap riveted to the upper web plate
what consists of lower section
single extrusion consisting of the lower cap and web plate.
structural crosspieces that combine with spars and stringers to make up the framework of the wing.
ribs
where do ribs extend from
wing leading edge to the rear spar or to the trailing edge of the wing.
what does the ribs give to the wing
cambered shape and transmit the load from the skin and stringers to the spars.
ribs are also used where
ailerons, elevators, rudders, and stabilizers
designed to carry part of the flight and ground loads in combination with the spars and ribs.
wing skin
may be made from a wide variety of
materials such as fabric, wood, or aluminum.
wing skin
kind of skin that can provide skin of varied thickness
Chemically milled aluminum skin
are streamlined enclosures used primarily to house the engine and its components.
nacelles
other name for nacelles
pods
They usually present a round or elliptical profile to the wind thus reducing aerodynamic drag.
nacelles
rigid structure used to hold the heavy aircraft engine in its place and position under or over an aircraft’s wings.
pylon
incorporated to isolate the engine compartment from the rest of the aircraft.
firewall
stainless steel or titanium bulkhead that contains a fire in the confines of the nacelle rather than letting it spread throughout the airframe.
firewall
These are the structural assemblies to which the engine is fastened. They are usually constructed from chrome/molybdenum steel tubing in light
aircraft and forged chrome/nickel/ molybdenum assemblies in larger aircraft.
engine mounts
detachable panels covering those areas into which access must be gained regularly, such as the engine and its accessories.
cowling
It is designed to provide a smooth airflow over the nacelle and to protect the engine from damage.
cowling
also known as the tail sect
empennage
what does most empennage design consist of
tail cone, fixed aerodynamic surfaces or stabilizers, and movable aerodynamic surfaces.
fixed surfaces on an empennage
horizontal stabilizer, vertical stabilizer
moveable surfaces on an empennage
rudder, elevator
two major groups of flight control surfaces
primary or main flight control surfaces and secondary or auxiliary flight control
directional control of a fixed-wing aircraft takes place around what axes?
lateral, longitudinal, and vertical axes
what are the primary flight control surfaces
ailerons, elevator, rudder
are attached to the trailing edge of both wings and when moved, rotate the aircraft around the longitudinal axis.
ailerons
is attached to the trailing edge of the horizontal stabilizer. When it is moved, it alters aircraft pitch, which is the attitude about the horizontal or lateral axis.
elevator
hinged to the trailing edge of the vertical stabilizer. the aircraft rotates about the
vertical axis (yaw). shows the primary flight controls of a light aircraft and the movement they create relative to the three axes of flight.
rudder
most common high-lift devices used on aircraft. These surfaces, which are attached to the trailing edge of the wing, increase both lift and induced drag for any given AOA.
flaps
increases the angle of attack at which the wing will maintain its laminar airflow, resulting in the ability to fly the aircraft slower and still maintain control.
slats
is a device found on the upper surface of many heavy and high-performance aircraft. It is stowed flush to the wing’s upper surface. When deployed, it rises up into the airstream and disrupts the laminar airflow of the wing, thus reducing
spoiler
similar to flight spoilers in construction can also be found on the upper surface of the wings of heavy and high-performance
speed brakes
force of the air against a control surface during the high speed of flight can make it difficult to move and hold that control surface in the deflected position.
tabs
to maintain a uniform flight path and recover from the various upsetting forces. Also, to achieve the best performance, the aircraft must have the proper response to the movement of
the controls.
stability
pilot action of moving the flight controls, providing the aerodynamic force that induces the aircraft to follow a desired flight path. When an aircraft is said to be controllable, it means that the aircraft responds easily and promptly to movement of the controls.
control
when is an aircraft in a state of equilibrium?
when the sum of all the forces acting on the aircraft and all the moments is equal to zero
Is the initial tendency of an aircraft to return to its original position when it’s disturbed.
static stability
exists when the disturbed object tends to return to equilibrium.
positive static stability
exists when the disturbed object tends to continue in the direction of disturbance.
negative static stability
exists when the disturbed object has neither tendency, but remains in equilibrium in the direction of disturbance.
neutral static stability
Is how the airplane responds over time to a disturbance.
dynamic stability
deals with the resulting motion with time.
static stability
motion about the aircraft’s longitudinal (fore and aft) axis is a lateral, or rolling, motion. The tendency to return to the original attitude from such motion is this.
lateral stability
occurs when the angle of attack becomes so great that the laminar airflow separates from the surface of an airfoil, leaving an area of burbling that destroys the low-pressure area normally existing at the upper surface of a wing in flight.
stall
how does the stall warning activate
wing is nearly stalled, the upward airflow moves the vane
