Login or Register for FREE!
Subelement K

Aircraft

Section 70

Instrument Landing System (ILS)

What is the frequency range of the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport?

  • 108.10 kHz to 111.95 kHz.
  • 329.15 MHz to 335.00 MHz.
  • 329.15 kHz to 335.00 kHz.
  • Correct Answer
    108.10 MHz to 111.95 MHz.

What is the frequency range of the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport?

108.10 MHz to 111.95 MHz.

The question asks for the frequency RANGE.

The Instrument Landing System (ILS), guides airplanes both horizontally and vertically.

Great explanation on a YouTube video from the FlightInsight channel, titled How ILS Works | Instrument Landing System Explained | IFR Training, 11:40 minutes (set at 1.5 speed to go faster)

From Wikipedia's article Instrument landing system

"ILS uses two directional radio signals, the localizer (108 to 112 MHz frequency), which provides horizontal guidance, and the glideslope (329.15 to 335 MHz frequency) for vertical."

The horizontal guidance is provided by ground transmitters of 90 Hz and 150 Hz signals, so that the airplane stays within 10° of the centerline, and must correct if within 35° of the centerline on either side.

For vertical orientation, the same ground system of is simply turned sideways, providing upper 90 Hz and lower 150 Hz signals (Glideslope Signal) , so that the airplane stays within the 3° angle.

For more information well-illustrated, please see Boldmethod site, for the article How An ILS Works.

See Wikipedia's article Instrument landing system.

Please see the FAA article Ground-Based Navigation - Instrument Landing System (ILS)

Last edited by markadlerdallas. Register to edit

Tags: none

What is the frequency range of the marker beacon system used to indicate an aircraft's position during an Instrument Landing System (ILS) approach to an airport's runway?

  • The outer, middle, and inner marker beacons’ UHF frequencies are unique for each ILS equipped airport to provide unambiguous frequency-protected reception areas in the 329.15 to 335.00 MHz range.
  • The outer marker beacon’s carrier frequency is 400 MHz, the middle marker beacon’s carrier frequency is 1300 MHz, and the inner marker beacon’s carrier frequency is 3000 MHz.
  • Correct Answer
    The outer, the middle, and the inner marker beacon’s carrier frequencies are all 75 MHz but the marker beacons are 95% tone-modulated at 400 Hz (outer), 1300 Hz (middle), and 3000 Hz (inner).
  • The outer, marker beacon’s carrier frequency is 3000 kHz, the middle marker beacon’s carrier frequency is 1300 kHz, and the inner marker beacon’s carrier frequency is 400 kHz.

What is the frequency range of the marker beacon system used to indicate an aircraft's position during an Instrument Landing System (ILS) approach to an airport's runway?

The outer, the middle, and the inner marker beacon’s carrier frequencies are all 75 MHz but the marker beacons are 95% tone-modulated at 400 Hz (outer), 1300 Hz (middle), and 3000 Hz (inner).

The Instrument Landing System (ILS), guides airplanes both horizontally and vertically.

Please see Wikipedia's article on Marker beacon

For more information well-illustrated, please see Boldmethod site, for the article How An ILS Works.

See Wikipedia's article Instrument landing system.

Please see the FAA article Ground-Based Navigation - Instrument Landing System (ILS)

Last edited by markadlerdallas. Register to edit

Tags: none

Which of the following is a required component of an Instrument Landing System (ILS)?

  • Altimeter: shows aircraft height above sea-level.
  • Correct Answer
    Localizer: shows aircraft deviation horizontally from center of runway.
  • VHF Communications: provide communications to aircraft.
  • Distance Measuring Equipment: shows aircraft distance to VORTAC station.

Which of the following is a required component of an Instrument Landing System (ILS)?

Localizer: shows aircraft deviation horizontally from center of runway.

The Instrument Landing System (ILS), guides airplanes both horizontally and vertically.

The horizontal guidance is provided by ground transmitters of 90 Hz and 150 Hz signals, so that the airplane stays within 10° of the centerline, and must correct if within 35° of the centerline on either side.

For vertical orientation, the same ground system of is simply turned sideways, providing upper 90 Hz and lower 150 Hz signals (Glideslope Signal) , so that the airplane stays within the 3° angle.

For more information well-illustrated, please see Boldmethod site, for the article How An ILS Works.

See Wikipedia's article Instrument landing system.

Please see the FAA article Ground-Based Navigation - Instrument Landing System (ILS)

Last edited by markadlerdallas. Register to edit

Tags: none

What type of antenna is used in an aircraft’s Instrument Landing System (ILS) glideslope installation?

  • A vertically polarized antenna that radiates an omnidirectional antenna pattern.
  • A balanced loop reception antenna.
  • Correct Answer
    A folded dipole reception antenna.
  • An electronically steerable phased-array antenna that radiates a directional antenna pattern.

What type of antenna is used in an aircraft’s Instrument Landing System (ILS) glideslope installation?

A folded dipole reception antenna.

See Wikipedia's article on Instrument landing system

View the YouTube video from FlightInsight channel called How ILS Works | Instrument Landing System Explained | IFR Training, 11:40 minutes.

For more information, please see Everything RF site for the article What is a Folded Dipole Antenna?

Also, see Electronics Notes site for the article Folded Dipole Antenna / Aerial

And, very in-depth information, on the Antenna Experts site for the article on Instrument Landing Systems (ILS) Antenna

Last edited by markadlerdallas. Register to edit

Tags: none

Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport. The localizer beam system:

  • Operates within the assigned frequency range of 108.10 to 111.95 GHz.
  • Produces two amplitude modulated antenna patterns; one pattern above and one pattern below the normal 2.5 degree approach glide path of the aircraft.
  • Frequencies are automatically tuned-in when the proper glide slope frequency is selected on the aircraft’s Navigation and Communication (NAV/COMM) transceiver.
  • Correct Answer
    Produces two amplitude modulated antenna patterns; one pattern with an audio frequency of 90 Hz and one pattern with an audio frequency of 150 Hz, one left of the runway centerline and one right of the runway centerline.

Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport. The localizer beam system:

Produces two amplitude modulated antenna patterns; one pattern with an audio frequency of 90 Hz and one pattern with an audio frequency of 150 Hz, one left of the runway centerline and one right of the runway centerline.

The Instrument Landing System (ILS), guides airplanes both horizontally and vertically.

The horizontal guidance is provided by ground transmitters of 90 Hz and 150 Hz signals, so that the airplane stays within 10° of the centerline, and must correct if within 35° of the centerline on either side.

For vertical orientation, the same ground system of is simply turned sideways, providing upper 90 Hz and lower 150 Hz signals (Glideslope Signal) , so that the airplane stays within the 3° angle.

For more information well-illustrated, please see Boldmethod site, for the article How An ILS Works.

See Wikipedia's article Instrument landing system.

Please see the FAA article Ground-Based Navigation - Instrument Landing System (ILS)

Last edited by markadlerdallas. Register to edit

Tags: none

On runway approach, an ILS Localizer shows:

  • Correct Answer
    Deviation left or right of runway center line.
  • Deviation up and down from ground speed.
  • Deviation percentage from authorized ground speed.
  • Wind speed along runway.

On runway approach, an ILS Localizer shows:

Deviation left or right of runway centerline.

The Instrument Landing System (ILS), guides airplanes both horizontally and vertically.

The horizontal guidance is provided by ground transmitters of 90 Hz and 150 Hz signals, so that the airplane stays within 10° of the centerline, and must correct if within 35° of the centerline on either side.

For vertical orientation, the same ground system of is simply turned sideways, providing upper 90 Hz and lower 150 Hz signals (Glideslope Signal) , so that the airplane stays within the 3° angle.

For more information well-illustrated, please see Boldmethod site, for the article How An ILS Works.

See Wikipedia's article Instrument landing system.

Please see the FAA article Ground-Based Navigation - Instrument Landing System (ILS)

Last edited by markadlerdallas. Register to edit

Tags: none

Go to 69 Go to 71