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Correct ANSWER is (d) Position of the aircraft

The best I can explain: The FMS continually monitors the aircraft envelope and ensures that the speed envelope restrictions are not BREACHED. It also computes the optimum speeds for the various phases of the flight profile. This is carried out taking into account factors such as: Aircraft weight – computed from a knowledge of the take-off weight and the fuel consumed (MEASURED by the ENGINE flow meters), CG position – computed from known aircraft loading and fuel consumed, Flight level and flight plan constraints, Wind and temperature models, Company route cost index.

Right OPTION is (a) True

Explanation: The FMS AIRCRAFT POSITION always uses the inertial position. This computation is not possible if the inertial position is not valid, and in this case, all the FMS NAVIGATION and flight planning functions are no longer available. FBW system also fails in the case of an INS shut down since it uses INS for feedback.

Correct answer is (d) 28 days

The explanation: The navigation DATABASE is updated every 28 days, according to the ICAO AiRAC cycle, and is held in non-volatile memory. It is clearly ESSENTIAL to maintain the RECENCY and quality of the database and the operator is RESPONSIBLE for the detail CONTENTS of the database which is to ARINC 424 format.

Correct ANSWER is (d) GPS only

The explanation is: Each FMS COMPUTES the AIRCRAFT position and the position accuracy. The FMS computed position is an optimum combination of the inertial position and the GPS or radio position, depending on which equipment provides the most accurate data. This results in four navigation MODES: Inertial (IRS) – GPS, Inertial (IRS) – DME/DME, Inertial (IRS) – VOR/DME, Inertial (IRS) only. The only GPS is not used as the position information is within a radius where the aircraft is flying.

Right choice is (a) Kalman filter

The best I can EXPLAIN: The FMS combines the DATA from the navigational SOURCES, comprising the INERTIAL systems, GPS and the radio navigation systems, in a Kalman filter to derive the best estimate of the aircraft position. Each navigation system has its own ADVANTAGES and limits, a Kalman filter combines the resource from all the systems to provide a more accurate position of the aircraft.

Correct option is (B) False

The best explanation: The standby computer does not perform any CALCULATIONS, but is regularly UPDATED by the master FMC. In the case of a single FMC failure, the standby FMC PROVIDES data to FMS connected with the FAILED FMC.

Correct option is (c) SINGLE mode

The BEST explanation: In Single mode OPERATING mode of the FMS two of the FMC is not in operation and this might cause ONE of the two FMS to fail. Hence both the FMS get information from one FMC.

Right choice is (b) Independent mode

To EXPLAIN I would SAY: In the Independent Mode, FMS-1 and FMS-2 are both operative, but there is no data exchange between them because they disagree on ONE or more items such as aircraft position, GROSS weight, etc.

The CORRECT answer is (d) 3

The EXPLANATION: There are a total of three Flight Management Computers FMC -A, FMC -B, FMC -C. They are NECESSARY to carry out the necessary FUNCTIONAL computations. They can be reconfigured to maintain the system operation in the event of failures.

Right option is (a) Keyboard and CURSOR Control Unit

For explanation I would say: The FLIGHT crew can NAVIGATE through the pages of FMS and can consult, enter or modify the data via the Keyboard and Cursor Control Unit (KCCU). The Keyboard and Cursor Control Unit (KCCU) enables the flight crew to navigate through the FMS pages on the MFD and enter and modify data on the MFD and can also perform some flight plan revisions on the lateral Navigation Display (ND).

Right choice is (B) 2

For explanation I WOULD SAY: There are two independent FMS in a typical commercial aircraft’s COCKPIT. FMS-1 is on the Captain’s side and FMS-2 on the First Officer’s side to carry ou the flight management FUNCTIONS. The reason why both are independent is that when one fails the other can take over.

Correct option is (a) Control over graphical and textual FMS DATA

For EXPLANATION: The EFIS Control Panel (EFIS CP) PROVIDES the means for the FLIGHT crew to control the graphical and textual FMS data that appear on the ND and PFD. Control over flight plan and performance is GIVEN by MFD. Navigation through the pages is by KCCU.

The correct choice is (d) Target Detection and Locking System

For explanation: The cockpit interfaces to the flight crew provided by each FMS comprise a Navigation DISPLAY (ND), a Primary Flight Display (PFD), a Multi-Function Display(MFD), a Keyboard and Cursor Control Unit (KCCU) and an ELECTRONIC Flight Instrument System (EFIS) Control PANEL (EFIS CP).

The CORRECT option is (a) Flight Management System

Easiest EXPLANATION: The above figure REPRESENTS flight management system. The throttle, Flight Management Computer, Data storage, NAVIGATION and display systems, and the autopilot together is called the FMS.

The correct option is (C) Automatically switch between different types of communication

Easiest explanation: The TASKS of the FMS include Flight guidance and lateral and vertical control of the aircraft flight path, Monitoring the aircraft flight envelope and computing the optimum speed for each phase of the flight and ensuring safe MARGINS are maintained with respect to the minimum and maximum speeds over the flight envelope, AUTOMATIC control of the engine thrust to control the aircraft speed. However, the communication systems are taken care manually by the pilot.

Correct option is (a) True

Explanation: Since GPS does not use radio beams to ALIGN the aircraft to the runway center line the final approach PATH need not be limited to straight line APPROACHES, but can be CURVED or stepped, horizontally or vertically. The life cycle costs of a GBAS is also only a fraction of ILS or MLS.

Right choice is (b) False

The EXPLANATION is: The response of the jet engine THRUST to throttle angle movement is not instantaneous and APPROXIMATES to that of a SIMPLE first-order filter with a time constant which is typically in the range 0.3 to 1.5 seconds, depending on the thrust setting and flight condition. Clearly, the lag in the throttle servo actuator response should be small compared with the jet engine response.

Correct option is (d) FADEC

The best explanation: The FADEC or Full Authority Digital Engine Control is a system that controls all ASPECTS of the engine performance. SINCE there are a lot of variables involved in the control of different engines, the WORKLOAD of the PILOT is increased. The FADEC system is used to reduce the workload at the same TIME giving full control of the engine to the pilot. It also ensures maximum engine performance at different flight conditions.

Right answer is (a) To align with the RUNWAY

The best I can explain: Just prior to touchdown a ‘kick off drift’ maneuver is initiated through the rudder control so that the AIRCRAFT is rotated about the yaw axis to align it with the runway. This ENSURES the undercarriage wheels are parallel to the runway center LINE so that no sideways velocity is EXPERIENCED by the wheels when they make contact with the runway.

The CORRECT OPTION is (d) Small NEGATIVE height

Easiest explanation: In the control law for auto flare, HREF is a small negative height, or bias, which ensures there is STILL a small downwards velocity at touchdown. This avoids the long exponential ‘tail’ to reach zero velocity and enables a reasonably PRECISE touchdown to be achieved.

Right answer is (b) To reduce airspeed and rate of descent

To EXPLAIN I would say: The flare maneuver is the increase in pitch of the aircraft seconds before touching the GROUND. This is done to reduce the airspeed and the rate of descent. If the flare is not executed correctly it may result in a runway OVERRUN, landing gear collapse or a tail STRIKE.

The CORRECT choice is (d) Decision height of 5m

To explain I would say: The autopilot requirements and operational limits for a category III visibility conditions are a PROBABILITY of catastrophic failure of less than 10−7 per hour, fully automatic landing system with FLARE, runway GUIDANCE required to taxi point. The decision height for a category IIIC condition is 0m. No system is yet certified for category IIIc operation.

Correct answer is (c) Runway LENGTH

Explanation: The two basic parameters USED to define the VISIBILITY category are the DECISION height, that is the minimum vertical visibility for the landing to proceed and the runway visual range. The length of a runway is not used to define visibility category.

The correct option is (B) ILS LOCALIZER receiver

To explain I would SAY: The Localizer coupling loop is integrated with the HEADING command loop to manage the heading of the aircraft. It is a closed loop system which continuously corrects with respect to the ILS Localizer. The error in flight path is corrected with respect to the localizer beam by MEANS of a localizer receiver in the aircraft.

Correct OPTION is (B) AIRCRAFT range is close to zero

For explanation I would say: In the localizer coupling loop gain increases as range between aircraft and runway decreases. The gain reaches a POINT where it becomes too LARGE and the loop becomes unstable. Thus gain scheduling with range is required.

The CORRECT option is (d) 1 m

Best explanation: The navigation position ACCURACY of 1 m which can be achieved with the differential GPS technique is being exploited in the US for landing guidance with a system called the GROUND Based Augmentation System, GBAS. The Ground Based Augmentation System, when installed at an AIRPORT, will be able to provide the high integrity and accurate guidance necessary for landing in Cat. III visibility CONDITIONS.

The correct answer is (a) 2.91 m/s

The explanation is: Vertical velocity at the start of flare = approach speed x glide SLOPE angle. THUS Vv= 66.87* x sin(2.5°) = 2.91 m/s .*[CONVERTING knots to m/s].

Right option is (b) Proportional plus integral

To explain: The auto-flare LOOP is a high-order SYSTEM; apart from the lags present in the filtered rad.alt. signals there are also the lags present in the RESPONSE of the pitch attitude command loop. This loop controls and its response is significantly slower at the low speeds during the approach. A proportional plus integral CONTROL term is used in the auto-flare controller to ensure accuracy and some phase advance is generally provided to compensate for the lags in the loop and hence IMPROVE the loop stability and damping.

Correct CHOICE is (b) 50 ft

To explain: The AUTO flare is initiated around 50 ft where the aircraft is over or very near the runway THRESHOLD so that the radio altimeter is measuring the HEIGHT of the aircraft above the runway. Low RANGE radio altimeters are used to ensure accuracy.

The correct answer is (b) 75 MHZ

The EXPLANATION: The marker beacon transmissions are at 75 MHz. The MIDDLE marker beacon is LOCATED at a DISTANCE of between 1,000 and 2,000 m from the runway threshold and the outer marker beacon is situated at a distance of between 4,500 and 7,500 m from the middle marker.

The correct answer is (c) Decision HEIGHT

To explain I would say: This minimum permitted ceiling for vertical VISIBILITY for the landing to PROCEED is known as the decision height or DH. A very HIGH integrity autopilot system is required for fully automatic landing below a DH of 100 ft – Cat. III conditions.

The correct option is (C) Category III

To explain: Visibility CONDITIONS are divided into three categories, namely Category I, Category II and Category III, depending on the vertical visibility ceiling and the runway VISUAL range (RVR). Category III includes zero visibility conditions.

The CORRECT OPTION is (d) Weight of the aircraft

Explanation: The height LIMITS and VISIBILITY conditions in which the autopilot can be used to carry out a glide slope coupled approach to the RUNWAY depends on the visibility category to which the autopilot system is certified for operation, the ILS ground installation standard, the runway lighting installation and the airport’s runway traffic control capability.

Correct option is (B) UHF

Explanation: The glide slope or glide path TRANSMISSION is at UHF frequencies from 329.3 to 335 MHz frequency and provides information to the AIRCRAFT as to whether it is FLYING above or below the defined descent path of nominally 2.5◦, for the airport concerned. The glide slope receiver output is proportional to the ANGULAR deviation γV, of the aircraft from the center of the glide slope beam which in turn corresponds with the preferred descent path.

The correct answer is (b) Localizer transmitter and glide slope transmitter

Explanation: ILS system basically comprises a localiser transmitter and a glide slope transmitter located by the AIRPORT runway together with two or three radio marker beacons located at SET distances ALONG the approach to the runway. The airborne equipment in the aircraft comprises receivers and antennas for the localiser, glide slope and marker transmissions.

The CORRECT answer is (a) Instrument landing system

For explanation I would say: ILS or instrument landing system is a radio based approach guidance system installed at MAJOR airports and airfields where the RUNWAY LENGTH exceeds 1800 m which provides guidance in poor visibility conditions during the approach to the runway.

The correct choice is (c) SBAS

Easy explanation: SBAS or Satellite Based Augmentation SYSTEMS exploiting DIFFERENTIAL GPS techniques will be able to provide RELIABLE and accurate approach path guidance in CATEGORY II visibility conditions. This will be INCREASINGLY used in the future.

The correct option is (d) DENSITY of air

For EXPLANATION I would say: The altitude control loop works using, Where H is the required height or altitude, θ is AIRCRAFT pitch ANGLE and α is angle of incidence.

Correct choice is (c) Stable and damped response

For explanation I WOULD say: The height error GAIN is chosen so that the frequencymax is well below the BANDWIDTH of pitch attitude loop to ensure a stable and well damped height loop response. If the frequency is high, it might lead to oscillations in the vertical AXIS.

Right choice is (a) Rate of change of heading

To elaborate: is the Rate of change of heading if the forward velocity of the aircraft is U and the BANK angle is ɸ. The function of the heading CONTROL mode of the autopilot is to STEER the aircraft along a particular setof direction.is USED assuming the aircraft is in coordinated turn.

Correct choice is (B) Pitch, roll and yaw control

Easiest explanation: The pitch attitude control loop and the heading control loop, with its inner loop COMMANDING the AIRCRAFT bank ANGLE, are thus fundamental inner loops in a common autopilot control mode. They are short, fast period loops which continuously control the control surfaces of an aircraft to maintain the pilot command.

Right choice is (d) Housekeeping management

Best explanation: The Light Management System performs various functions such as Automatic navigation and guidance including ‘4D’ navigation, Presentation of INFORMATION, Management of aircraft systems, Efficient management of FUEL, Reduction of operating costs. Housekeeping management is a separate system which takes care of air CONDITIONING, entertainment systems, ETC.

Correct option is (a) Autopilot

The explanation: The basic function of the autopilot is to control the flight of the AIRCRAFT and maintain it on a predetermined path in space WITHOUT any action being required by the pilot. The autopilot can thus RELIEVE the pilot from the fatigue and tedium of having to maintain CONTINUOUS control of the aircraft’s flight path on a long duration flight so the pilot can concentrate on other tasks and the management of the MISSION.

The correct answer is (a) GENERATE commands to the inner flight control loop

Easy explanation: The autopilot exercises a guidance function in the outer loop and generates commands to the inner flight control loop. These commands are GENERALLY attitude commands which operate the aircraft’s control SURFACES through a CLOSED flight control loop system so that the aircraft rotates about the pitch and roll axes until the measured pitch and bank angles are equal to the commanded angles. The CHANGES in the aircraft’s pitch and bank angles then cause the aircraft flight path to change through the flight path kinematics.