Which statement about stick force per g is correct ? [ Formation assignment ]

Question 237-1 : The stick force per g must have both an upper and lower limit in order to ensure acceptable control characteristics the stick force per g increases when centre of gravity is moved aft the stick force per g can only be corrected by means of electronic devices stability augmentation in case of an unacceptable value if the slope of the fe n line becomes negative generally speaking this is not a problem for control of an aeroplane

exemple 337 The stick force per g must have both an upper and lower limit in order to ensure acceptable control characteristics. — The stick force per g must have both an upper and lower limit in order to ensure acceptable control characteristics.

Examples of aerodynamic balancing of control surfaces are ?

Question 237-2 : Servo tab spring tab seal between the wing trailing edge and the leading edge of control surface balance tab horn balance and mass balance mass in the nose of the control surface horn balance and mass balance spring tab servo tab and power assisted control

exemple 341 Servo tab, spring tab, seal between the wing trailing edge and the leading edge of control surface. — Illustration of a seal between the wing trailing edge and the leading edge of control surface . 2762.when you move the control surface it generates an area of high pressure and an area of low pressure .this differential pressure creates a compensation force acting in the same way of the pilot's action Servo tab, spring tab, seal between the wing trailing edge and the leading edge of control surface.

Which phenomenon is counteracted with differential aileron deflection ?

Question 237-3 : Adverse yaw aileron reversal sensitivity for spiral dive turn co ordination

exemple 345 Adverse yaw. — To generate lift we have to move air downwards and to roll into a banked attitude to turn we have to lift one wing while dropping the other to lift a wing we have to generate more lift and so we lower the aileron on that side we don't get something for nothing and so this extra lift increases the drag meanwhile dropping the other wing by moving the aileron upwards reduces the drag the increased drag generated by the down going aileron causes the nose to yaw in the opposite direction to the roll and this is called adverse yaw ..with differential ailerons one aileron is raised a greater distance than the other aileron is lowered for a given movement of the control wheel this produces an increase in drag on the descending wing the greater drag results from deflecting the up aileron on the descending wing to a greater angle than the down aileron on the rising wing while adverse yaw is reduced it is not eliminated completely Adverse yaw.

An aeroplane has a servo tab controlled elevator what will happen if the ?

Question 237-4 : Pitch control sense is reversed pitch control is lost the servo tab now works as a negative trim tab the pitch control forces double

exemple 349 Pitch control sense is reversed. — . /com en/com080 378 jpg.only the tab is left functioning it is not connected to the elevator but works in the unnatural sense to drive the elevator in the natural sense so with the elevator locked you only have very limited control from the tab only and in the unnatural sense and of course you have no trim or balance fuction left Pitch control sense is reversed.

A horn balance in a control system has the following purpose ?

Question 237-5 : To decrease stick forces to prevent flutter to obtain mass balancing to decrease the effective longitudinal dihedral of the aeroplane

exemple 353 To decrease stick forces. — .a horn balance is a method of aerodynamic balancing for the ailerons elevators and rudders and is used to produce a balancing moment in order to reduce amount of force required to move the controls .flutter is prevented by the use of mass balancing by adding weights to the control surface to move their cg not by horn balancing .example of horn balance . 1537 To decrease stick forces.

An increase in geometric dihedral in a steady sideslip condition at constant ?

Question 237-6 : Increase the required lateral control force decrease the required lateral control force not affect the required lateral control force decrease the stick force per g

exemple 357 Increase the required lateral control force. — Stability is the ability of the aircraft to return to equalibrium without input from the pilot .equalibrium is where all the forces are zero .it does not mean that the aircraft returns to the same heading or altitude but that the relative airflow is in such a position that the aircraft will be balanced in the question we are trying to hold the aircraft in a steady side slip which means we are holding the aircraft out of equalibrium .a stable aircraft with geometric dihedral will try to oppose this .so we will be required to hold greater forces to maintain the angle which is opposing the natural tendency of the aircraft .if we increase the geometric dihedral even further we will need more effort to hold that sideslip as stability will be increased Increase the required lateral control force.

When a jet transport aeroplane takes off with the cg at the forward limit and ?

Question 237-7 : Rotation will require a higher than normal stick force there will be a tendency to over rotate early nose wheel raising will take place rotation will be normal using the normal rotation technique

exemple 361 Rotation will require a higher than normal stick force. — Rotation will require a higher than normal stick force.

Which statement is correct .i on fully hydraulic powered flight controls there ?

Question 237-8 : I is incorrect ii is correct i is incorrect ii is incorrect i is correct ii is correct i is correct ii is incorrect

exemple 365 I is incorrect, ii is correct — .flight control force balance can normally be achieved hydraulically as part of the actuator sizing you have to remember that even though fly by wire aircraft recieve their control inputs electronically the control surfaces are still powered by the hydraulic system s which are sized to overcome mass balance and flight loads but to prevent flutter mass balancing is required and also in case of manual reversion total hydraulic failure .and with a fully hydraulic powered flight controls there is no need for trim tabs you can move the controls where you like and use an artificial trim I is incorrect, ii is correct

An aeroplane performs a right turn the slip indicator is left of neutral one ?

Question 237-9 : More left rudder more right rudder less right bank a higher turn rate

exemple 369 More left rudder. — .in a skidding turn the ball will be displaced in the opposite direction of turn in the direction of turn for a slipping turn . /com en/com080 593 jpg.one way to co ordinate the turn is to apply more left rudder More left rudder.

When roll spoilers are extended the part of the wing on which they are mounted ?

Question 237-10 : Experiences a reduction in lift which generates the desired rolling moment in addition there is a local increase in drag which suppresses adverse yaw experiences extra drag which generates a yawing moment the speed difference between both wings generates the desired rolling moment stalls this causes a difference in lift between both wings which generates the desired rolling moment is forced downwards as a reaction to the increased drag

exemple 373 Experiences a reduction in lift, which generates the desired rolling moment. in addition there is a local increase in drag, which suppresses adverse yaw. — Experiences a reduction in lift, which generates the desired rolling moment. in addition there is a local increase in drag, which suppresses adverse yaw.

When power assisted controls are used for pitch control ?

Question 237-11 : A part of the aerodynamic forces is still felt on the column trimming is superfluous aerodynamic balancing of the control surfaces is meaningless they only function in combination with an elevator trim tab

exemple 377 A part of the aerodynamic forces is still felt on the column. — A part of the aerodynamic forces is still felt on the column.

The pitch angle is defined as the angle between the ?

Question 237-12 : Longitudinal axis and the horizontal plane longitudinal axis and the chord line chord line and the horizontal plane speed vector axis and the longitudinal axis

exemple 381 Longitudinal axis and the horizontal plane. — . 682.the angle of attack should not be confused with the pitch angle or attitude of aircraft which are angles relative to the horizontal while the angle of attack is in respect to the relative airflow Longitudinal axis and the horizontal plane.

Which statement in respect of a trimmable horizontal stabiliser is correct ?

Question 237-13 : An aeroplane with a forward c g requires the stabiliser leading edge to be lower than for one with an aft c g in the same trimmed condition because take off speeds do not vary with centre of gravity location the need for stabiliser adjustment is dependent on flap position only an aeroplane with a forward c g requires the stabiliser leading edge to be higher than for one with an aft c g in the same trimmed condition at the forward c g limit stabiliser trim is adjusted fully nose down to obtain maximum elevator authority at rotation during take off

exemple 385 An aeroplane with a forward c.g. requires the stabiliser leading edge to be lower than for one with an aft c.g. in the same trimmed condition. — .if the cg is moved aft it results in a larger nose down pitching moment which has to be compensated for by placing a download on the tailplane this can be achieved by deflecting the elevator up although this results in high trim drag at higher airspeeds on large aircraft small movements of the variable incidence stabiliser allow the trimming to be carried out but with reduced trim drag .an upward deflection of the elevator is required to trim the aircraft so think of the stabiliser as a large elevator with its trailing edge moving in the same direction as the elevator to achieve this you must therefore lower the leading edge of the stabiliser to produce the necessary download .note once in a trimmed condition on fully powered flying controls the elevator will then align itself with the stabiliser to reduce the tail load and also the loads acting on the hinges and servo actuator on power assisted controls there is however no guarantee that this occurs due to downwash and configuration effects that can alter the flow over the surface it is also fair to say that trim drag also increases fuel consumption An aeroplane with a forward c.g. requires the stabiliser leading edge to be lower than for one with an aft c.g. in the same trimmed condition.

An example of differential aileron deflection during initiation of left turn is ?

Question 237-14 : Left aileron 5° up right aileron 2° down left aileron 2° up right aileron 5° down left aileron 5° down right aileron 2° up left aileron 2° down right aileron 5° up

exemple 389 Left aileron: 5° up. right aileron: 2° down. — . /com en/com080 510 jpg.the aileron linkage causes the up going aileron the move through a larger angle than the down going aileron this increases the drag on the up aileron and reduces it on the down aileron and so reduces the difference in drag between the two wings Left aileron: 5° up. right aileron: 2° down.

An aeroplane is provided with spoilers and both inboard and outboard ailerons ?

Question 237-15 : Inboard ailerons and roll spoilers outboard ailerons and roll spoilers inboard and outboard ailerons outboard ailerons only

exemple 393 Inboard ailerons and roll spoilers. — Inboard ailerons and roll spoilers.

Mass balancing of control surfaces is used to ?

Question 237-16 : Prevent flutter of control surfaces limit the stick forces ensure that the control surfaces are in the mid position during taxiing increase the stick force stability

exemple 397 Prevent flutter of control surfaces. — .flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces as the airspeed increases there may be a point at which the structural damping is insufficient to damp out the motions which are increasing due to aerodynamic energy being added to the airfoil this vibration can cause structural failure and therefore considering flutter characteristics is an essential part of designing an aircraft . 813.to counteract this phenomenon the control surface's cg must be as close as possible of the hinge the torsion axis Prevent flutter of control surfaces.

In what phase of flight are the outboard ailerons if fitted not active ?

Question 237-17 : Cruise take off until lift off approach landing with a strong and gusty crosswind to avoid over controlling the aeroplane

The most important factor determining the required position of the trimmable ?

Question 237-18 : Position of the aeroplane's centre of gravity total mass of the aeroplane stall speed centre of gravity position of the fuel

exemple 405 Position of the aeroplane's centre of gravity. — Position of the aeroplane's centre of gravity.

What is the position of the elevator in relation to the trimmable horizontal ?

Question 237-19 : Elevator deflection is zero at a forward cg the elevator is deflected upward and at an aft cg it is deflected downward the elevator is always deflected slightly downward in order to have sufficient remaining flare capability the position depends on speed the position of flaps and slats and the position of the centre of gravity

exemple 409 Elevator deflection is zero. — .a fully hydraulically operated flight controls is an irreversible system and the trim is a redatum as there is no physical connection between the stick and control therefore there will be no elevator deflection when trimmed Elevator deflection is zero.

In straight flight as speed is increased whilst trimming to keep the stick ?

Question 237-20 : The elevator is deflected further downwards and the trim tab further upwards both elevator and trim tab are deflected further downwards the elevator and trim tab do not move the elevator is deflected further upwards and the trim tab further downwards

exemple 413 The elevator is deflected further downwards and the trim tab further upwards. — . /com en/com080 641 jpg. The elevator is deflected further downwards and the trim tab further upwards.

Rotation around the longitudinal axis is called ?

Question 237-21 : Rolling pitching yawing slipping

exemple 417 Rolling. — Img /com en/com080 547a jpg. Rolling.

Rotation around the normal axis is called ?

Question 237-22 : Yawing rolling pitching slipping

Which of these statements about a trimmable horizontal stabiliser is correct ?

Question 237-23 : A trimmed aeroplane with an aft cg requires the stabiliser leading edge to be higher than in the case of a forward cg in the same condition because take off speeds do not vary with cg position the need for stabiliser adjustment is dependent on flap position only a trimmed aeroplane with an aft cg requires the stabiliser leading edge to be lower than in the case of a forward cg in the same condition at the aft cg limit stabiliser trim is adjusted fully nose up to obtain maximum elevator authority at rotation during take off

exemple 425 A trimmed aeroplane with an aft cg requires the stabiliser leading edge to be higher than in the case of a forward cg in the same condition. — . /com fr/com080 298 jpg.with a forward cg the tailplane must produce a high downward force to stabilise the aircraft if the cg moves aft closer to the centre of lift the downward force is reduced the.trimmable horizontal stabiliser leading edge is higher than in the case of a forward cg to keep the balance of lift and total weight constant A trimmed aeroplane with an aft cg requires the stabiliser leading edge to be higher than in the case of a forward cg in the same condition.

When comparing an elevator trim system with a stabiliser trim system which of ?

Question 237-24 : An elevator trim is more sensitive to flutter an elevator trim is able to compensate larger changes in pitching moments an elevator trim is more suitable for aeroplanes with a large cg range an elevator trim produces lower trim drag

.on a stabiliser trim system the whole tailplane is moving this large surface is less sensitive to flutter than an elevator trim system the elevator trim tab system is a small auxiliary control surface hinged at the trailing edge of the elevators

When comparing a stabiliser trim system with an elevator trim system which of ?

Question 237-25 : An elevator trim is less suitable for aeroplanes with a large cg range a stabiliser trim is more sensitive to flutter an elevator trim is able to compensate larger changes in pitching moments an elevator trim is more suitable for aeroplanes with a large cg range

exemple 433 An elevator trim is less suitable for aeroplanes with a large cg range. — .a horizontal trimmable stabiliser enables a larger cg range and is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes .on a stabiliser trim system the whole tailplane is moving this large surface is less sensitive to flutter than an elevator trim system the elevator trim tab system is a small auxiliary control surface hinged at the trailing edge of the elevators An elevator trim is less suitable for aeroplanes with a large cg range.

Comparing the differences between a horizontal trimmable stabiliser and an ?

Question 237-26 : I is correct ii is correct i is incorrect ii is incorrect i is incorrect ii is correct i is correct ii is incorrect

exemple 437 I is correct, ii is correct. — .the effects of a trim tab runaway are more serious > wrong .the effects of a stabiliser trim runaway are more serious > correct.a jammed stabiliser trim causes less control difficulty > wrong .a jammed trim tab causes less control difficulty > correct.stabiliser trim runaway is more serious because it requires more force to be exerted by the pilot to overcome the movement of the stabiliser trim because stabilisers pivot around a central hinge point they are extremely sensitive to control inputs and aerodynamic loads antiservo tabs are incorporated on the trailing edge to decrease sensitivity they deflect in the same direction as the stabilisator this results in an increase in the force required to move the stabiliser .whereas a jammed trim tab is less serious because it requires less force to be exerted by the pilot in order to overcome it I is correct, ii is correct.

Which aerodynamic design features can be used to reduce control forces ?

Question 237-27 : Horn balance balance tab servo tab mass balance horn balance artificial feel system servo tab bobweight control surfaces with increased area balance tab control surfaces with increased area behind the hinge artificial feel system

In general control forces are reduced by ?

Question 237-28 : A horn balance servo tab and spring tab mass balancing a trim tab and spring tab a balance tab forward shift of the cg and a servo tab a servo tab spring tab and mass balancing

What are the primary roll controls on a conventional aeroplane ?

Question 237-29 : The ailerons the rudder symmetrically deflected spoilers asymmetrically extended leading edge flaps

exemple 449 The ailerons. — The ailerons.

Artificial feel is required ?

Question 237-30 : With fully powered flight controls when the flight control surfaces are fitted with control tabs or trim tabs when there is a trimmable stabiliser with power assisted flight controls

exemple 453 With fully powered flight controls. — With fully powered flight controls.

Consider an aeroplane with .1 a trim tab .2 fully powered hydraulic controls ?

Question 237-31 : 1 moves forward 2 does not change 1 does not change 2 moves forward 1 moves forward 2 moves forward 1 does not change 2 does not change

.after trimming for a speed increase . the neutral position of the control column moves forward with a trim tab . the neutral position of the control column with a fully powered hydraulic controls and an adjustable horizontal stabiliser .when speed increases the pilot need to increase back pressure on the pitch control this moves the elevator up to hold the elevator in this new position the trim tab is moved down .but with fully powered hydraulic controls trimming does not reduce the effective range of pitch control as the elevator remains approximately neutral when the aircraft is trimmed

The tab in the figure represents . err a 081 946 ?

Question 237-32 : A servo tab a balance tab a trim tab an anti balance tab

The tab in the figure represents . err a 081 947 ?

Question 237-33 : A balance tab that also functions as a trim tab a control tab a trim tab an antibalance tab

exemple 465 A balance tab that also functions as a trim tab. — A balance tab that also functions as a trim tab.

When comparing a stabiliser trim system with an elevator trim system which of ?

Question 237-34 : A stabiliser trim is able to compensate larger changes in pitching moments a stabiliser trim is more sensitive to flutter an elevator trim is more suitable for aeroplanes with a large cg range an elevator trim is able to compensate larger changes in pitching moments

Spoilers mounted on the wing upper surface can be used to ?

Question 237-35 : Assist the ailerons assist the elevators prevent aeroplane yaw following engine failure increase lift and drag

exemple 473 Assist the ailerons. — Assist the ailerons.

In straight flight as speed is reduced whilst trimming to keep the stick force ?

Question 237-36 : The elevator is deflected further upwards and the trim tab further downwards both elevator and trim tab are deflected further upwards the elevator and trim tab do not move the elevator is deflected further downwards and the trim tab further upwards

exemple 477 The elevator is deflected further upwards and the trim tab further downwards. — . /com en/com080 641 jpg. The elevator is deflected further upwards and the trim tab further downwards.

If the airspeed is doubled whilst maintaining the same control surface ?

Question 237-37 : Become four times greater double increase by the square root of the airspeed become four times smaller

exemple 481 Become four times greater. — .recall the lift equation .lift = cl x 1/2 rho x v² x s.where lift equals the coefficient of lift x dynamic pressure x velocity squared x surface area of the air foil .if speed is doubled dynamic pressure aerodynamic force is 1/2 rho x v² will be four times greater Become four times greater.

What kind of horizontal control surface is shown in the figure . err a 081 1016 ?

Question 237-38 : All flying tail elevator canard frise type control

exemple 485 All-flying tail. — .the figure shows a 'moving tailplane' or 'all flying tail' . /com en/com080 1016 jpg.all flying tail on a robin dr 400 All-flying tail.

Comparing the differences between a horizontal trimmable stabiliser and an ?

Question 237-39 : I is correct ii is incorrect i is incorrect ii is incorrect i is incorrect ii is correct i is correct ii is correct

exemple 489 I is correct, ii is incorrect. — .trimming in pitch is achieved by a small trim tab at the rear of the elevator or by moving the whole tailplane the stabiliser these both produce aerodynamic forces .these forces depend on 1/2 rho v² cl which changes with the amount of deflection changes in angle of attack and s the surface area .a stabiliser is much bigger that a trim tab it will produce much larger forces for the same ias and deflection .comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab .correct elevator trim tab statements . when trimmed for zero elevator stick force an elevator trim tab causes more drag . a trim tab runaway causes less control difficulty . a jammed trim tab causes less control difficulty ..correct horizontal trimmable stabiliser statements . a horizontal trimmable stabiliser enables a larger cg range . a stabiliser trim is a more powerful means of trimming . the effects of a stabiliser trim runaway are more serious . a stabiliser trim is more suitable for jet transport aeroplanes because of their large speed range . a stabiliser trim is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes ..the horizontal stabilizer which can be used either by itself or in addition to a trimming tab is more effective than trim tabs at high mach numbers the incidence can be varied to balance out of trim forces . /com en/com080 1186a jpg... /com en/com080 1186b jpg. trimmable horizontal stabilizer on an airbus a319 I is correct, ii is incorrect.

Comparing the differences between a horizontal trimmable stabiliser and an ?

Question 237-40 : I is correct ii is incorrect i is incorrect ii is incorrect i is incorrect ii is correct i is correct ii is correct

exemple 493 I is correct, ii is incorrect. — .trimming in pitch is achieved by a small trim tab at the rear of the elevator or by moving the whole tailplane the stabiliser these both produce aerodynamic forces .these forces depend on 1/2 rho v² cl which changes with the amount of deflection changes in angle of attack and s the surface area .a stabiliser is much bigger that a trim tab it will produce much larger forces for the same ias and deflection .comparing the differences between a horizontal trimmable stabiliser and an elevator trim tab .correct elevator trim tab statements . when trimmed for zero elevator stick force an elevator trim tab causes more drag . a trim tab runaway causes less control difficulty . a jammed trim tab causes less control difficulty ..correct horizontal trimmable stabiliser statements . a horizontal trimmable stabiliser enables a larger cg range . a stabiliser trim is a more powerful means of trimming . the effects of a stabiliser trim runaway are more serious . a stabiliser trim is more suitable for jet transport aeroplanes because of their large speed range . a stabiliser trim is more suitable to cope with the large trim changes generated by the high lift devices on most jet transport aeroplanes ..the horizontal stabilizer which can be used either by itself or in addition to a trimming tab is more effective than trim tabs at high mach numbers the incidence can be varied to balance out of trim forces . /com en/com080 1186a jpg... /com en/com080 1186b jpg. trimmable horizontal stabilizer on an airbus a319 I is correct, ii is incorrect.

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