aircraft flight controls Flashcards
are aerodynamic devices that allow a pilot to adjust
and control the aircraft’s flight attitude.
Aircraft flight control surfaces
rotation about lateral axis
pitch ( elevator )
rotation about vertical axis
yaw ( rudder )
rotation about longitudinal axis
roll ( ailerons )
credited with developing the first practical control
surfaces
Wright brothers
modern control surfaces used what?
warping
he made hinged control surfaces, the same type of concept first patented some four decades earlier in the United Kingdom.
Glenn Curtiss
what is the technique used and patented by wright brothers?
consisted of a system of pulleys and cables to twist the trailing edges of the wings in opposite directions.
it has the advantage of not causing stresses that are a problem of wing warping and are easier to build into structures.
Hinged control surfaces
was an early system for lateral (roll) control of a fixed-wing aircraft.
Wing warping
it is an imaginary line about which a body rotates
axis
The simplest way to understand the axes is to think of them as long rods passing through the aircraft where each will intersect at the aircraft
center of gravity
axis that extends lengthwise ( nose through tail )
longitudinal axis “roll”
axis that extends crosswise ( wing tip through wing tip )
lateral axis “pitch”
what are the three airplane movements?
pitch, roll, and yaw
what are the three primary control surfaces?
aileron, elevator/stabilator, and rudder
what are the three axes of rotation?
longitudinal, lateral, and vertical
are means by which a pilot controls the direction and attitude of an aircraft in flight.
Aircraft flight controls
Flight control systems are subdivided into?
primary and secondary flight controls.
are required to safely control an aircraft during flight and consist of ailerons, elevators (or, in some installations,
stabilator) and rudder
primary flight controls
are intended to improve the
aircraft performance characteristics or to relieve excessive control loading
secondary flight controls
consist of high lift devices such as slats and flaps as well as flight spoilers and
trim systems.
secondary flight controls
carefully designed to provide adequate responsiveness to control inputs while allowing a natural feel.
Aircraft control systems
the controls usually feel soft and sluggish, and the aircraft responds slowly to control applications.
low airspeeds
It controls roll about the longitudinal axis
Ailerons
the controls become increasingly firm and aircraft response is more rapid.
higher airspeeds
connected by cables, bell cranks, pulleys, and/or push-pull tubes which are controlled by a control/cyclic stick.
Ailerons
It is attached to the outboard trailing edge of each wing and move in the opposite direction from each other.
Ailerons
Since the downward deflected aileron produces more lift as
evidenced by the wing raising, it also produces more drag.
Adverse Yaw
this added drag causes the wing to slow down slightly.
adverse yaw
a result of differential drag and the slight difference in the velocity of the left and right wings.
adverse yaw
more pronounced at low airspeeds.
adverse yaw
when pressure is applied to the control wheel, or control stick, the aileron that is being raised pivots on an offset hinge
fries-type ailerons
one aileron is raised a greater distance than the other aileron and is lowered for a given movement of the control wheel or control stick.
differential ailerons
This projects the leading edge of the aileron into the airflow and creates drag
fries-type ailerons
It helps equalize the drag
created by the lowered aileron on the opposite wing and reduces adverse yaw.
fries-type ailerons
what are the four common types of flaps
o Plain Flap
o Split Flap
o Slotted Flap
o Fowler Flap
It is attached to the trailing edge of the wing, increase both lift and induced drag
for any given AOA.
flap
It is the most common high-lift devices used on aircraft.
flap
It is deflected from the lower surface of the airfoil and produces a slightly greater increase in lift than the plain flap.
split flap
it is the most popular flap on aircraft today.
slotted flap
It increases the lift coefficient significantly more than plain or split flaps.
slotted flap
It contains a gap that vastly increases airflow across the entire flap, enhancing its effectiveness.
slotted flap
this flap design not only changes the camber of the wing, it also increases the wing area.
fowler flaps
instead of rotating down on a hinge, it slides backwards on tracks. In the first portion of its extension, it increases the drag very little, but increases the lift a great deal as it increases both the area and camber.
fowler flaps
High-lift devices also can be applied to the leading edge of the airfoil. The most common types are?
o Fixed Slots
o Movable Slats
o Leading Edge Flaps
o Leading Edge Cuffs
it directs airflow to the upper wing surface and delay airflow separation at higher angles of attack.
Fixed slots
The slot does not increase the wing camber, but allows a higher maximum CL because the stall is delayed until the
wing reaches a greater AOA.
fixed slot
Consists of leading edge segments that move on tracks. At low angles of attack, each slat is held flush against the wing’s leading edge by the
high pressure that forms at the wing’s leading edge
movable slats
Are used to increase both CL-MAX and the camber of the
wings. This type of leading edge device is frequently used in conjunction with trailing edge flaps and can reduce the nose-down pitching movement produced
by the latter.
Leading Edge Flaps
Are also used to increase both CL-MAX and the camber of the wings. Unlike leading edge flaps and trailing edge flaps, leading edge cuffs
are fixed aerodynamic devices.
Leading Edge Cuffs
Are used to relieve the pilot of the need to maintain constant pressure on the flight controls, and usually consist of flight deck controls and small hinged devices attached to the trailing edge of one or more of the primary flight control surfaces.
trim system
deployed from the wings to spoil the smooth airflow,
reducing lift and increasing drag.
Spoilers
The most common installation on small aircraft is a single trim tab attached to the trailing edge of the elevator.
trim tabs
Common types of trim systems include what?
trim tabs, balance tabs, antiservo tabs, ground adjustable tabs, and an adjustable stabilizer.
Looks like trim tabs and are hinged in approximately the same places as trim tabs.
balance tabs
MUST REMEMBER!!
The essential difference between the two is that the balancing tab is coupled to the
control surface rod so that when the primary control surface is moved in any
direction, the tab automatically moves in the opposite direction.
it is a small portion of a flight control surface that deploys in such a way that it helps to move the entire flight control surface in the direction that the pilot wishes it to go.
SERVO TABS
is a dynamic device that deploys to decrease the pilots work load and de-stabilize the aircraft.
SERVO TABS
Are sometimes referred to as flight tabs and are used primarily on large aircraft.
SERVO TABS
work in the same manner as balance tabs except, instead of moving in the opposite direction, they move in the same direction as the trailing
edge of the stabilator.
ANTISERVO TABS
also functions as a trim device to relieve control pressure and maintain the stabilator in the desired position.
ANTISERVO TABS
This tab is bent in one direction or the other while on the ground to apply a trim force to the rudder. The correct displacement is determined by trial and error.
ground adjustable tabs
Rather than using a movable tab on the trailing edge of the elevator, some aircraft have an?
adjustable stabilizer
what is used to control the movement of yaw
what is the movement controlled by the elevator
pitch
what is the type of stability controlled by the rudder?
directional
what is the axes of rotation of the elevator
lateral
what primary flight control is used to control the movement roll
aileron
what is the axes of rotation of aileron
longitudinal
what is the type of stability controlled by aileron
lateral
where is rudder located
vertical stabilizer
which primary flight control is located in vertical stabilizer
rudder
what is the most popular flap on aircraft today
slotted flap
