ILS part 2

Question 1

The Localizer operates in the VHF band between ? and ? MHz to provide ? channels

Answer 1

The Localizer operates in the VHF band between 108 and 111.975 MHz to provide 40 channels

Question 2

This part (localizer) of the frequency band is shared with VOR: the frequencies allocated are ? decimals and ? decimals + ? MHz.

Answer 2

This part of the frequency band is shared with VOR: the frequencies allocated are odd decimals and odd decimals + 0.05 MHz.

Question 3

The glide path operates in the UHF band between 329.15 and 335 MHz to provide ? complementary channels. e.g. 329.15, 329.3, 329.45, 329.6 - 335 MHz

Answer 3

The glide path operates in the UHF band between 329.15 and 335 MHz to provide 40 complementary channels. e.g. 329.15, 329.3, 329.45, 329.6 - 335 MHz

Question 4

All markers transmit at ? MHz ? modulation. There is no interference problem as the radiation pattern is a narrow fan-shaped vertical beam

Answer 4

All markers transmit at 75 MHz amplitude modulation. There is no interference problem as the radiation pattern is a
narrow fan-shaped vertical beam

Question 5

The DME ranges are zero referenced to the -

Answer 5

ILS runway threshold

Question 6

The localizer coverage sector extends from the transmitter to distances of:

• __ NM (46.3 km) within plus or minus __° from the centre line.
• __ NM (31.5 km) between __° and __° from the centre line.
• __ NM (18.5 km) outside ± __° if coverage is provided

The glide path coverage extends from the transmitter to a distance of at least:

__ NM (18.5 km) in sectors of _° in azimuth on each side of the centre line

Answer 6

• 25 NM (46.3 km) within plus or minus 10° from the centre line.
• 17 NM (31.5 km) between 10° and 35° from the centre line.
• 10 NM (18.5 km) outside ± 35° if coverage is provided

10 NM (18.5 km) in sectors of 8° in azimuth on each side of the centre line

Question 7

The lobes are transmitted on a single VHF ILS frequency. In

order that an aircraft’s ILS receiver can distinguish between the lobes:

Answer 7

• the right hand lobe (the blue sector) has a 150 Hz modulation.
• the left hand lobe (the yellow sector) has a 90 Hz modulation.

Question 8

the angular displacement of the aircraft from the centreline of the localizer relates to the -

Answer 8

Depth of modulation(DOM)

Question 9

The glide slope UHF transmitter is located to one side of the runway approximately ? m from the runway edge, ? m upwind of the threshold.

Answer 9

The glide slope UHF transmitter is located to one side of the runway approximately 200 m from the runway edge, 300 m upwind of the threshold.

Question 10

Full scale deflection of the localiser on the HSI/CDI?

For the GS?

Answer 10

2. 5 degrees

0. 7

Question 11

False glide path beams are sensed -

Answer 11

above the correct glide path

Question 12

Marker beacons:

Cockpit light, Ident, frequency, touchdown range:

1. OM
2. MM
3. IM

Answer 12

1. Blue, 2 dashes/sec, 400hz, 3.5 - 6nm
2. Yellow, alt dots and dashes 3/sec, 1300hz, 500ft - 3500ft.
3. White, 6 dots/sec, 3 000hz, 250 - 1500ft.