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Correct option is (c) INSTRUMENT Landing System

Explanation: ILS REFERS to Instrument Landing System. It is an aircraft system that enables pilots to take an instrument approach to landing if they are unable to ESTABLISH visual CONTACT with the runway.

The correct answer is (a) Ground

Easiest explanation: ILS operates as a ground based INSTRUMENT APPROACH system. It PROVIDES the aircraft with horizontal and vertical GUIDANCE just before and during landing.

Right answer is (B) Localizer

Easiest explanation: Localizer is the lateral component of the ILS. WHEREAS, glide slope is the vertical component. The localizer works like cooperation between the transmitting airport runway and the RECEIVING cockpit instruments.

The CORRECT option is (c) Lateral

Explanation: The instrument landing system of an aircraft involves two INDEPENDENT SUB systems. The two systems are the localizer and the glide slope. The former PROVIDES lateral guidance whereas the later provides vertical guidance.

Right choice is (d) Departure

The EXPLANATION: The localizer system is generally located beyond the departure end of a runway. The system COMPRISES a number of PAIRS of DIRECTIONAL antennas.

The correct choice is (a) 108.10 MHz to 111.95 MHz

To explain I would say: The FREQUENCY range for LOC carrier frequencies is 108.10 MHz to 111.95 MHz. Each ANTENNA transmits a narrow BEAM, for the LOC.

Right choice is (b) 3

For EXPLANATION I would say: The center of the glide slope signal is ARRANGED so as to define a glide path of ROUGHLY 3 degrees above the horizontal reference. A CARRIER signal is used to transmit the glide slope signal.

Right answer is (b) True

The BEST EXPLANATION: True, the pilot controls the aircraft such that the glide slope indicator remains in the CENTER of the display. This is to ensure that the aircraft is following the glide PATH and it reaches the runway at the proper touchdown point.

Correct ANSWER is (c) Back BEAM

The best explanation: ILS beams intended for use in ONE direction only are called back beams. These beams are of HELP during the approach, but the use of back beam localizer reduces PRECISION compared to normal use.

Right option is (c) 40

The BEST explanation: There can be a maximum of 40 CHANNELS in an INSTRUMENT Landing System. The channels are alternatively modulated at 90 Hz and 150 Hz. Signals from these channels are transmitted by MEANS of co-located antennas.

Correct choice is (b) Instrument guidance system

Easiest explanation: IGS REFERS to Instrument guidance system. It is a modified ILS USED to accommodate a non-straight APPROACH. A famous example for the IGS is approach to runway 13 at Hong Kong KAI Tak Airport.

The correct option is (a) 75 MHz

For explanation: The marker beacons operate at a carrier frequency of 75 MHz. The beacons transmit signals which in TURN activate an INDICATOR on the flight deck INSTRUMENT PANEL. This further ENABLES the pilot to hear the tone of the beacon.

The correct OPTION is (c) Radar altimeter

Explanation: The radar altimeter instrument is used in CATII and CATIII approaches to determine the decision height of an aircraft. In contrary, the CATI APPROACH relies solely on altimeter indications.

The correct option is (d) 2

Explanation: CATIII localizers must cut off WITHIN 2 seconds of detecting an ERROR. On the other hand, CATI localizers may cut off within 10 seconds of detecting an error. Higher CAT CATEGORIES involve SHORTER cut off times.

Right ANSWER is (a) 2 nautical miles

To explain I would say: Generally, an AIRCRAFT is established by at least 2 nautical miles prior to the final approach. At a controlled airport, ATC will DIRECT the aircraft to the localizer course via CERTAIN assigned headings.

Correct CHOICE is (B) True

For explanation I would SAY: True, ALS is a mandatory requirement to perform CATIII landing operations. Further, the systems should ALSO have sufficient capability and reliability in order to control the aircraft for a safe landing.

Correct choice is (a) False

The best I can explain: False, the first Category III Microwave Landing SYSTEM for civil aviation was commissioned at Heathrow airport. It was commissioned in March 2009 and REMOVED from SERVICE in 2017.

Right answer is (B) 26 January 1938

For explanation I would say: It was on 26 January 1938, that a scheduled passenger airliner landed USING the instrument landing SYSTEM for the first time ever, in the United States of America. The flight was operated by the PENNSYLVANIA Central Airlines.

The correct CHOICE is (d) Category I

The EXPLANATION is: The Wide Area AUGMENTATION System PROVIDES PRECISION guidance to Category I standards. The Local Area Augmentation System is under development to provide guidance for Category III minimums or lower.

The correct answer is (d) Radio Detection and Ranging

The best I can explain: RADAR refers to Radio Detection and Ranging.It can be used to detect many objects such as aircrafts, ships, SPACECRAFT along with information about WEATHER formations, and TERRAIN.

The CORRECT choice is (a) Radio

Easy explanation: RADAR systems use radio waves. It is a system USED to determine PARAMETERS like the RANGE, angle, or velocity of different objects.

Correct answer is (C) LIDAR

Explanation: LIDAR is a system SIMILAR to radar. It is a system that predominantly uses infrared light from lasers rather than radio WAVES. It makes USE of the other parts of the electromagnetic spectrum.

Right choice is (B) TRUE

For explanation I would say: True, radio WAVES are INVISIBLE to the human eye. Moreover, these waves are ALSO invisible to optical cameras.

The correct OPTION is (b) 1940

Easy explanation: The TERM RADAR is used as an acronym for Radio Detection and Ranging. The term was introduced in 1940 and was first used by the US NAVY.

The correct ANSWER is (c) UNITED Kingdom

The best I can explain: Cavity MAGNETRON was developed in the United Kingdom, its development brought NEW advancements in various sub systems and improved the efficiency of relatively smaller sub systems.

The correct option is (c) FREQUENCY shift

Explanation: A motion that BRINGS about change in the number of wavelengths between the reflector and the radar, in turn CAUSES a frequency shift in the system. Such a shift may EITHER ENHANCE or degrade the performance of a system.

Right answer is (b) True

For explanation: True, an ACTIVE radar system TRANSMITS a signal that is in turn reflected back to the RECEIVER. In the CONTRARY, passive radar systems rely on the OBJECT to send a signal to the receiver.

The correct choice is (b) Rain

The explanation: Circular polarization TECHNIQUE is used to nullify the INTERFERENCE caused DUE to rain. Random polarization technique is used for HARD surfaces such as rocks, FRACTAL surfaces or soil.

Right choice is (a) False

The BEST explanation: False, the linear polarization returns usually INDICATE metal surfaces. The orientation of a linearly POLARIZED EM wave is DEFINED by the direction of the electric FIELD vector.

The correct option is (d) Linear

Explanation: A radar BEAM usually follows a linear path in vacuum. Although the beam follows a slightly curved path in the atmosphere, this CHANGE is DUE to the variation of the RI of air.

Right OPTION is (B) Decline

To elaborate: The amount of reflected SIGNALS decline rapidly with an increase in the distance travelled by the SIGNAL. Further, the NOISE component brings in a radar range limitation, affecting the performance of the device.

The correct choice is (b) Signal to NOISE ratio

For explanation: SNR refers to signal to noise ratio. It can be defined as the ratio of the signal power to the noise power within the desired signal. HIGHER the SNR, better is the SYSTEM.

Right ANSWER is (c) Radar mile

Easiest explanation: Radar mile is a term used to describe the amount of TIME a radar pulse takes in order to travel one nautical mile, then REFLECT off a target and again return back to the radar ANTENNA. One nautical mile is defined as 1,852 m.

Right CHOICE is (a) FREQUENCY

The best I can explain: The Doppler device separates any clutter from an aircraft by means of a frequency spectrum. The SEPARATION is done in such a manner that each INDIVIDUAL signal can be SEPARATED by using various velocity differences.

The correct choice is (a) FALSE

For EXPLANATION: False, the FREQUENCY shift in a RADAR instrument is directly proportional to distance travelled by the instrument. Also, the frequency shift increases with increased time delay in the instrument.