Assembly and Rigging Flashcards
The auxiliary (tail) rotor of a helicopter permits the pilot to compensate for and/or accomplish which of the following?
Torque and directional control
The vertical flight of a helicopter is controlled by
collective pitch changes
A reduction in anti-torque thrust will cause the
tail to pivot in the direction of torque rotation around the main rotor axis
A decrease in pitch angle of the tail rotor blades on a helicopter
tail to pivot in the direction of torque rotation around the main rotor axis
In rotorcraft external-loading, the ideal location of the cargo release is where the line of action passes
through the centre of gravity at all times
The acute angle formed by the chord line of a wing and the relative wind is known as the
angle of attack
A helicopter in forward flight, cruise configuration, changes direction by
tilting the motor rotor disk in the desired direction
The purpose in checking main rotor blade tracking is to determine the
relative position of the blades during rotation
In a hovering helicopter, equipped with a tail rotor, directional control is maintained by
varying the pitch of the tail rotor blades
If a single motor helicopter is in forward horizontal flight, the angle of attack of the advancing blade is
less than the retreating blade
Main rotor blades that do not come by the same amount during rotation are said to be out of
track
One purpose of the freewheeling unit required between the engine and helicopter transmission is to
automatically disengage the rotor from the engine in case of engine failure
Which statement is correct concerning torque effect on helicopters?
Torque direction is the opposite of the rotor blade direction
What is the purpose of the free-wheeling unit in a helicopter drive system?
It disengages the engine from the main rotor when engine RPM is less than rotor RPM
Movement about the longnitudinal axis (roll) in a helicopter is affected by movement of the
cyclic pitch control
Movemenbt about the lateral axis (pitch) in a helicopter is affected by movement of the
cyclic pitch control
Wing dihedral, a rigging consideration on most airplanes of conventional design, contributes most stability of the airplane about its
longnitudinal axis
Other than the manufacturer maintenance manual what other document could be used to determine the primary flight control surface deflection for an imported aircraft that is reassembled after shipment?
Aircraft Type Certificate Data Sheet
If a pilot reports that an airplanes 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
If the vertical fin of a single engine, propeller driven airplane is rigged properly, it will generally be parallel to
the vertical axis but not the longitudinal axis
An airplane which has good longitudinal stability should have a minimum tendency to
pitch
As the angle of attack of an airfoil increases, the centre of pressure will
move toward the leading edge
The angle of incidence is that acute angle formed by
a line parallel to the wing chord and a line parallel to the longitudinal axis of the aircraft
An aircraft centre of lift is usually located aft of its centre of gravity
so that the airplane will have a nose heavy tendency
An aircraft is controlled directionally about its vertical axis by the
rudder
The elevators of a conventional airplane are used to provide rotation about the
lateral axis
Washing-in the left wing of a monoplane, for purposes of rigging corrections after the flight test, will have what effect on the lift and drag of that wing?
Both drag and lift will increase due to increased angle of attack
What type of flap system increases the wing area and changes the wing camber?
Fowler flaps
If the right wing wing of a monoplane, is improperly rigged to a greater angle of incidence than designated in the manufacture’s specification, it will cause the
airplane to be off balance both laterally and directionally
The chord of a wing is measured from
leading edge to trailing edge
When the lift on a airfoil increases, the drag will
also increase
What physical factors are involved in the aspect ratio of airplane wings?
Span and control
Improper rigging of the elevator trim tab system will affect the balance of the airplane about its
lateral axis
An airplane that has a tendency to gradually increase a pitching moment that has been set into motion has
poor longitudinal stability
The purpose of wing slats is
to reduce stalling speed
The angle of incidence of an airplane at rest
does not change when in flight
Buffeting is the intermittent application of forces to a part of an airplane. It is caused by
an unsteady flow from turbulence
Movement of an airplane along its lateral axis (roll) is also movement
around or about the longitudinal axis controlled by the ailerons
The primary purpose of stall strips is to
stall the inboard portion of the wings first
If all, or a significant part of a stall strip is missing on a airplane wing, a likely result will be
asymmetrical lateral control at or near stall angles of attack
Rigging and alignment checks should not be undertaken in the open. However, if this can not be avoided, the aircraft should be positioned with the
nose into the wind
The correct dihedral angle can be determined by
using a dihedral board and bubble level along the front spar of each wing
The dihedral angle of a wing may be measured by placing a straightedge and level protractor on the
front spar
Where would you find precise information to perform a symmetry alignment check for a particular aircraft?
Aircraft Service or Maintenance Manual
Where is the buttock line of an aircraft
A width measurement left or right and parallel to the vertical centre line
Where is fuselage station No.137 located?
137 inches aft of zero or fixed reference line
Proper wing twist in a sheet metal constructed wing can usually be checked by utilizing a
bubble level and special fixtures described by the manufacturer
The vast majority of aircraft control cables are terminated with swaged terminals that must be
checked with a go-no-go gauge before and after, to show compliance with the manufactures requirements after the swaging operation
What non-destructive checking method is normally used to ensure that the correct amount of swaging has taken place when installing type terminals on aircraft control cables?
Use a terminal gauge to check the diameter of the swaged portion of the terminal
When inspecting a control cable turnbuckle for proper installation, determine that
the safety wire ends are wrapped a minimum 4 times around the terminal end shanks
Safety wire of .020-inch diameter may be used on parts having a nominal hole diameter of .045 inch and .062 with a spacing between the parts of
2 inches
If all instruction 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
Which is an acceptable safety device for a castle nut when installed on secondary structures?
Cotter pin
When installing a acceptable safety device for a castle nut when installed on secondary structure?
Cotter Pin
When installing a castle nut, start alignment with the cotter pin hole at the
minimum recommended torque plus friction drag torque
When used in close proximity to magnetic compasses, cotter pins are made of what material?
Corrosion resisting steel
When a fibre or nylon insert-type self-locking nut can be threaded on a bolt or stud through the insert with only the fingers, it should be
rejected
The purpose of the vertical fin is to provide
directional stability
How are changes in direction of a control cable accomplished?
Pulleys
What is the smallest size cable that may be used in primary control systems
1/8 inch
After repairing or re-covering a rudder, the surface should be rebalanced
to manufactures specification
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
broken strands
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
Very often, repairs to a control surface require static rebalancing of control surface. Generally, flight control balance condition may be determined by
the behavior of the trailing edge when the surface is suspended from its hinge points
Excessive wear on both of the sides of a control cable pulley grove is evidence of
pulley misalignment
Fairleads should never deflect the alignment of a cable more than
3 degrees
Where does the breakage of control cable wires occur most frequently
Breakage usually occurs where control cables pass over pulleys and through fairleads
With which system is differential control associated?
Aileron
Which system concerning the 100 hour inspection of an airplane equipped with a push pull tube type control system is true?
The threaded rod ends should be checked for the amount of threaded engagement by means of the inspection hole provided
If control cable are adjusted properly and the control surfaces tend to vibrate, the probable cause is
worn attachment fittings
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
Stability about the axis which runs parallel to the line of flight is known as
lateral stability
The purpose of spring tabs or servo tabs is to
assist the pilot in moving the control surfaces
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 up
Movement of the cockpit control toward the nose down position during ground operational check of the elevator tab trim system will cause the trailing edge of the trim tab to move in which direction?
Upward regardless of elevator position
If the control stick of an aircraft with properly rigged flight controls is moved forward and to the right, the left aileron will move
down and the elevator will move down
If the travel of an airplane’s control is correct but the cable are rigged exceptionally tight, what probable effect will this have when flying the airplane?
The airplane will be heavy on the controls
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
A universal propeller protractor used to measure the degrees of aileron travel should be zeroed
with the aileron at the NEUTRAL position
The universal propeller protractor can be used to measure
degrees of flap travel
A tension regulator in the flight control cable system of a large all-metal aircraft is used primarily to
retain a set tension
Differential control on an aileron system means that
the up travel is more than the down travel
Why is it generally necessary to jack and aircraft indoors for weighing
So that air currents do not destabilize the scales
Which should be accomplished before jacking an aircraft?
Install critical stress panels or plates
