Flight control

The elevators of a conventional airplane are used to provide rotation about the. longitudinal axis. lateral axis. vertical axis.

The angle of incidence is that acute angle formed by. the angular difference between the setting of the main airfoil and the auxiliary airfoil (horizontal stabilizer) in reference to the longitudinal axis of the aircraft. a line parallel to the wing chord and a line parallel to the longitudinal axis of the aircraft. a line parallel to the wing from root to tip and a line parallel to the lateral axis of the aircraft.

Proper wing twist in a sheet metal constructed wing can usually be checked by utilizing a. plum bob, string, and straightedge. bubble level and special fixtures described by the manufacturer. straightedge, tape measure, and carpenter's square.

Rigging and alignment checks should not be undertaken in the open. However, if this cannot be avoided, the aircraft should be positioned with the. tail into the wind. left wing into the wind. nose into the wind.

The primary purpose of stall strips is to. provide added lift at slow speeds. stall the inboard portion of the wings first. provide added lift at high angles of attack.

The correct dihedral angle can be determined by. measuring the angular setting of each wing at the rear spar with a bubble protractor. placing a straightedge and bubble protractor across the spars while the airplane is in flying position. using a dihedral board and bubble level along the front spar of each wing.

Where is fuselage station No. 137 located?. 137 centimeters aft of the nose or fixed reference line. 137 inches aft of the zero or fixed reference line. Aft of the engine.

Differential control on an aileron system means that. the down travel is more than the up travel. the up travel is more than the down travel. one aileron on one wing travels further up than the aileron on the opposite wing to adjust for wash-in and wash-out.

The cable-operated control system of an all-metal aircraft, not incorporating a temperature compensating device, has been rigged to the correct tension in a heated hangar. If the aircraft is operated in very cold weather, the cable tension will. decrease when the aircraft structure and cables become cold. increase when the aircraft structure and cables become cold. be unaffected if stainless steel cable is installed.

If control cables are adjusted properly and the control surfaces tend to vibrate, the probable cause is. worn attachment fittings. oil can effects on the control surfaces. excessive cable tension.

If the control stick of an aircraft with properly rigged flight controls is moved rearward and to the left, the right aileron will move. down and the elevator will move down. up and the elevator will move down. down and the elevator will move up.

An airplane which has good longitudinal stability should have a minimum tendency to. roll. pitch. yaw.

An airplane's center of lift is usually located aft of its center of gravity. so that the airplane will have a tail-heavy tendency. so that the airplane will have a nose-heavy tendency. to improve stability about the longitudinal axis.

If all instructions issued by the swaging tool manufacturer are followed when swaging a cable terminal, the resultant swaged terminal strength should be. the full rated strength of the cable. 80 percent of the full rated strength of the cable. 70 percent of the full rated strength of the cable.

As the angle of attack of an airfoil increases, the center of pressure will. move toward the trailing edge. remain stationary because both lift and drag components increase proportionally to increased angle of attack. move toward the leading edge.

Washing-in the left wing of a monoplane, for purposes of rigging corrections after flight test, will have what effect on the lift and drag of that wing?. Both drag and lift will decrease due to decreased angle of attack. Both drag and lift will increase due to increased angle of attack. The drag will decrease due to the effect of the lift increase.

If the control stick of an aircraft with properly rigged flight controls is moved forward and to the right, the left aileron will move. up and the elevator will move down. down and the elevator will move up. down and the elevator will move down.

The purpose of wing slats is to. reduce stalling speed. decrease drag. reduce lift.

A universal propeller protractor used to measure the degrees of aileron travel should be zeroed. with the aileron in the NEUTRAL position. with the aileron in the DOWN position. when the aircraft is in a level flight attitude.

A tension regulator in the flight control cable system of a large all-metal aircraft is used primarily to. increase the cable tension in cold weather. provide a means of changing cable tension in flight. retain a set tension.

The dihedral angle of a wing may be measured by placing a straightedge and level protractor on the. front spar. wing root. wing chord.

Dutch roll, a combination yawing and rolling oscillation that affects many sweptwing aircraft, is counteracted with. a flight director system. an aileron damper system. a yaw damper system.

Fairleads should never deflect the alignment of a cable more than. 12°. 8°. 3°.

Very often, repairs to a control surface require static rebalancing of the control surface. Generally, flight control balance condition may be determined by. checking for equal distribution of weight throughout the control surface. the behavior of the trailing edge when the surface is suspended from its hinge points. suspending the control surface from its leading edge in the stream line position and checking weight distribution.

Placing a piece of cloth around a stainless steel control cable and running it back and forth over the length of the cable is generally a satisfactory method of inspecting for. corrosion. broken strands. excessive wear.

(Refer to Figure 9.) When the outside air temperature is 80°F, select the acceptable 3/16 cable tension range. 130 pounds minimum, 140 pounds maximum. 117 pounds minimum, 143 pounds maximum. 120 pounds minimum, 140 pounds maximum.

When inspecting a control cable turnbuckle for proper installation, determine that. no more than four threads are exposed on either side of the turnbuckle barrel. the terminal end threads are visible through the safety hole in the barrel. the safety wire ends are wrapped a minimum of four turns around the terminal end shanks.

The angle of incidence of an airplane at rest. affects the dihedral of the wings in flight. is the same as the angle between the relative wind and the chord of the wing. does not change when in flight.

Where would the aviation mechanic find precise information to perform a symmetry alignment check for a particular aircraft?. Aircraft Specification or Type Certificate Data Sheet. Manufacturer's service bulletins. Aircraft service or maintenance manual.

Where is the buttock line or buttline of an aircraft?. A height measurement left or right of, and perpendicular to, the horizontal centerline. A width measurement left of, and perpendicular to, the vertical centerline. A width measurement left or right of, and parallel to, the vertical centerline.

If the vertical fin of a single-engine, propeller-driven airplane is rigged properly, it will generally be parallel to. the longitudinal axis but not the vertical axis. the vertical axis but not the longitudinal axis. both the longitudinal and vertical axes.

The universal propeller protractor can be used to measure. propeller track. aspect ratio of a wing. degrees of flap travel.

What type of flap system increases the wing area and changes the wing camber?. Fowler flaps. Slotted flaps. Split flaps.

The acute angle formed by the chord line of a wing and the relative wind is known as the. longitudinal dihedral angle. angle of incidence. angle of attack.

Aircraft flight control trim systems must be designed and installed so that the. pilot can determine the relative position of the trim tab from the cockpit. operating control and the trim tab will always move in the same direction. trim system will disengage or become inoperative if the primary flight control system fails.

The purpose of spring tabs or servo tabs is to. assist the pilot in moving the control surfaces. contribute to the static balance of the control surface. make in-flight trim adjustments possible.

What is the smallest size cable that may be used in aircraft primary control systems?. 1/4 inch. 5/16 inch. 1/8 inch.

What nondestructive checking method is normally used to ensure that the correct amount of swaging has taken place when installing swaged-type terminals on aircraft control cable?. Check the surface of the swaged portion of the terminal for small cracks which indicate incomplete swaging. Measure the finished length of the terminal barrel and compare with the beginning length. Use a terminal gauge to check the diameter of the swaged portion of the terminal.

Buffeting is the intermittent application of forces to a part of an airplane. It is caused by. incorrect rigging of flaps. an unsteady flow from turbulence. incorrect rigging of ailerons.

What physical factors are involved in the aspect ratio of airplane wings?. Thickness and chord. Span and chord. Dihedral and angle of attack.

After repairing or re-covering a rudder, the surface should be rebalanced. to its spanwise axis. in its normal flight position. to manufacturer's specifications.

During inspection of the flight control system of an airplane equipped with differential-type aileron control, side-to-side movement of the control stick will cause. each aileron to have a greater up travel (from the streamlined position) than down travel. each aileron to have greater down travel (from the streamlined position) than up travel. the left aileron to move through a greater number of degrees (from full up to full down) than the right aileron.

Stability about the axis which runs parallel to the line of flight is referred to as. longitudinal stability. lateral stability. directional stability.

An airplane that has a tendency to gradually increase a pitching moment that has been set into motion has. poor longitudinal stability. good lateral stability. poor lateral stability.

Which statement concerning the 100-hour inspection of an airplane equipped with a push-pull tube-type control system is true?. The threaded rod ends should not be adjusted in length for rigging purposes because the rod ends have been properly positioned and staked during manufacture. The terminal end threads of the turnbuckles should be visible through the safety hole in the barrel. The threaded rod ends should be checked for the amount of thread engagement by means of the inspection hole provided.

Excessive wear on both of the sides of a control cable pulley groove is evidence of. pulley misalignment. cable misalignment. excessive cable tension.

If the travel of an airplane's controls is correct but the cables are rigged exceptionally tight, what probable effect will this have when flying the airplane?. The airplane will tend to fall off on one wing. The airplane will be heavy on the controls. The pilot will be unable to fly the airplane hands-off.

Improper rigging of the elevator trim tab system will affect the balance of the airplane about its. lateral axis. longitudinal axis. vertical axis.

Where does the breakage of control cable wires occur most frequently?. Breakage usually occurs where cables pass over pulleys and through fairleads. Breakage sites are unpredictable and usually occur randomly anywhere along the length of a cable. Breakage usually occurs where cables are swaged to turnbuckle and ball terminals.

(Refer to Figure 8.) Identify the cable that is used in primary control systems and in other places where operation over pulleys is frequent. 2. 1. 3.

With which system is differential control associated?. Trim. Aileron. Elevator.

Movement of an airplane along its lateral axis (roll) is also movement. around or about the longitudinal axis controlled by the elevator. around or about the lateral axis controlled by the ailerons. around or about the longitudinal axis controlled by the ailerons.

If a pilot reports that an airplane flies left wing heavy, this condition may be corrected by. increasing the angle of incidence of the left wing, or decreasing the angle of incidence of the right wing, or both. increasing the dihedral angle of the left wing, or decreasing the dihedral angle of the right wing, or both. adjusting the dihedral angle of the left wing so that differential pressure between the upper and lower wing surfaces is increased.

How are changes in direction of a control cable accomplished?. Pulleys. Bell cranks. Fairleads.

When the lift of an airfoil increases, the drag will. decrease. also increase. increase while the lift is changing but will return to its original value.

An airplane is controlled directionally about its vertical axis by the. rudder. elevator(s). ailerons.

The purpose of the vertical fin is to provide. directional stability. longitudinal stability. lateral stability.

If the right wing of a monoplane is improperly rigged to a greater angle of incidence than designated in the manufacturer's specifications, it will cause the. airplane to be off balance both laterally and directionally. airplane to pitch and roll about the lateral axis. right wing to have both an increased lift and a decreased drag.

The chord of a wing is measured from. wingtip to wingtip. wing root to the wingtip. leading edge to trailing edge.

Movement of the flight deck control toward the nosedown position during a ground operational check of the elevator trim tab system will cause the trailing edge of the trim tab to move in which direction?. Downward regardless of elevator position. Upward regardless of elevator position. Downward if the elevator is in the UP position and upward if the elevator is in the DOWN position.

The vast majority of aircraft control cables are terminated with swaged terminals, that must be. corrosion treated to show compliance with the manufacturer's requirements after the swaging operation. pull tested to show compliance with the manufacturer's requirements after the swaging operation. checked with a go-no-go gauge before and after, to show compliance with the manufacturer's requirements after the swaging operation.