Chapter 6 Flight Controls

The elevator.

A trim tab positioned up forces the elevator down, causing the tail to move up and the nose to move down.

They increase both C_L-MAX and the camber of the wings.

Control-stop mechanisms and limited movement of the control column or rudder pedals.

To streamline the control surface and make the stabilator less sensitive by opposing the pilot's force.

To decrease excessively high control forces by counterbalancing air pressure against the primary control surface.

The longitudinal axis (roll).

A nonmovable metal trim tab on the rudder that is bent on the ground to apply a trim force.

Cable operated with a trim wheel or crank.

To prevent the pilot from inadvertently overcontrolling and overstressing the aircraft.

Rods, cables, pulleys, and sometimes chains.

To supply a mechanical load to lower the nose when aerodynamic efficiency is inadequate due to an aft CG condition.

Altitude and heading hold.

Because the aerodynamic forces are not excessive in certain aircraft.

The aircraft about the longitudinal axis using ailerons.

The rudder.

Anti-torque pedals, cyclic stick, and collective lever.

One with a horizontal surface of about the same size as a normal aft-tail design, and the other with a surface of the same size and airfoil as the aft-mounted wing (tandem wing configuration).

The upward deflection of one aileron decreases lift on that wing, while the downward deflection of the opposite aileron increases lift, causing the aircraft to roll.

Using anti-torque pedals.

To manipulate rotor pitch.

Rudder effectiveness increases with speed; larger deflections are needed at low speeds.

Control stops, elevator down springs, and stick pushers.

They can vary greatly depending on the type of aircraft flown.

By the pilot or coupled to a radio navigation signal.

Trim tabs, balance tabs, antiservo tabs, ground adjustable tabs, and adjustable stabilizers.

To decrease sensitivity and make the stabilator less prone to pilot-induced overcontrolling.

Flap extension may cause a nose-up or down pitching moment, requiring trim adjustment.

By destroying lift and creating more drag on one wing, causing the aircraft to bank and yaw.

Because it helps lift the weight of the aircraft, resulting in less drag for a given amount of lift.

Adverse yaw causes the aircraft to yaw opposite the direction of the bank.

Yaw.

Small general and sport category aircraft.

A one-piece horizontal tail surface that pivots up and down about a central hinge point.

It raises the stabilator’s trailing edge, pulling the nose of the aircraft up.

Ailerons change airflow and pressure distribution, affecting lift and drag on the airfoil/control surface combination.

To pivot the horizontal stabilizer about its rear spar.

A disconnect safety feature to disengage the system automatically or manually.

One aileron is raised a greater distance than the other, increasing drag on the descending wing.

To automatically deflect the rudder at the same time the ailerons are deflected, correcting for aileron drag.

By the left and right rudder pedals.

To keep an aircraft in level flight or on a set course.

Antiservo tabs move in the same direction as the stabilator, while trim tabs move in the opposite direction.

Control surfaces that combine the functions of flaps and ailerons.

The controls feel soft and sluggish, and the aircraft responds slowly.

Elevator back pressure must be applied.

To provide undisturbed airflow at high angles of attack and/or low airspeeds.

Ailerons, elevator (or stabilator), and rudder.

They remove the tail from the exhaust blast of the engines.

To increase lift and induced drag for any given angle of attack (AOA).

They significantly increase the lift coefficient more than plain or split flaps.

To control the forces of flight and the aircraft’s direction and attitude.

To reduce lift and increase drag during descent and landing.

The need to maintain constant pressure on the flight controls.

The interconnect cable and spring pull forward on the left rudder pedal to prevent yawing to the right.

Fowler flaps slide backwards on tracks and increase both wing area and camber.

It increases elevator camber, creating more lift and pitching the nose down.

The distance between the center of gravity (CG) and the horizontal tail surface, and the aerodynamic effectiveness of the horizontal tail surface.

They direct airflow to the upper wing surface and delay airflow separation.

To develop an adaptive neural network-based flight control system that improves aircraft performance and safety.

A forward CG may cause problems in holding the nose up.

The movement of the elevator is opposite to the direction of movement of the elevator trim tab.

To help move the entire flight control surface in the desired direction, decreasing the pilot's workload.

Higher drag on the outside wing that is producing more lift.

At low airspeeds, high angles of attack, and with large aileron deflections.

The canard creates lift to hold the nose up, while the aft-tail design exerts downward force to prevent the nose from rotating downward.

Differential ailerons, frise-type ailerons, coupled ailerons and rudder, and flaperons.

Slotted flaps produce much greater increases in maximum coefficient of lift (C L-MAX).

The elevator is above most effects of downwash, allowing consistent control movements.

Increased design stiffness of the vertical stabilizer to counter flutter.

They increase the airfoil camber, significantly increasing the coefficient of lift at a given AOA.

Ailerons, Elevator (or Stabilator), and Rudder.

Increased aileron deflection causes an increase in adverse yaw.

The elevator deflects up, creating a downward aerodynamic force and pitching the nose up.

It functions as a horizontal stabilizer located in front of the main wings, creating lift and holding the nose up.

The flap increases drag with little additional increase in lift.

To reduce complexity, weight, and limitations of mechanical flight control systems.

They provide essential information about the primary and secondary flight control systems of the aircraft.

They allow maximum increase in drag without airflow separation over the flaps.

The rudder moves left, causing the tail to move right and the nose to yaw left.

Systems that may consist of wing flaps, leading edge devices, spoilers, and trim systems.

Plain, split, slotted, and Fowler flaps.

Plain flap, Split flap, Slotted flap, Fowler flap, Slotted Fowler flap.

The aircraft about the longitudinal, lateral, and vertical axes using ailerons, elevator, and rudder.

To delay airflow separation and increase lift at higher angles of attack.

Fixed slots, movable slats, leading edge flaps, and cuffs.

A system that replaces physical connections between pilot controls and flight control surfaces with an electrical interface.

They pivot on an offset hinge to create drag and equalize the drag created by the lowered aileron on the opposite wing.

It simulates the feel of control reaction for the pilot.

The elevator must be moved a greater distance to raise the nose.

High angle of attack (AOA) with low airspeed and aft center of gravity (CG).

To improve airflow attachment at higher angles of attack, thus lowering stall speed.

Wing flaps, leading edge devices, spoilers, and trim systems.

Movable surfaces in a V-tail design that act as both rudder and elevator.

The elevator may streamline, causing the nose to pitch upward and potentially resulting in a stall.

By destroying lift, they transfer weight to the wheels.

A design utilizing two slanted tail surfaces that perform the functions of both elevator and rudder.

It mechanically moves the elevator toward a nose-down position, increasing speed and preventing a stall.