Instrument Landing System (ILS)

Question 1

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?

Answer 1

108.10 MHz to 111.95 MHz

Question 2

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?

Answer 2

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).

Question 3

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

Answer 3

Localizer: shows aircraft deviation horizontally from center of runway.

Question 4

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

Answer 4

A folded dipole reception antenna.

Question 5

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:

Answer 5

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.

Question 6

On runway approach, an ILS Localizer shows:

Answer 6

Deviation left or right of runway center line.