ILS

Question 1

Explain the purpose of an ILS

Answer 1

The Instrument Landing System is a precision approach aid comprising both ground and airborne electronic equipment which allow the pilot to maintain both direction and descent to a runway very precisely.

Question 2

The component that provide horizontal guidance?

Answer 2

Localiser

Question 3

The component that provide vertical guidance?

Answer 3

Glide Slope

Question 4

The 3 components of an ILS?

Answer 4

1. Localiser
2. Glide Slope
3. Outer and Middle markers

Question 5

On which frequency band does an ILS localiser operate?

Answer 5

VHF

Question 6

On which frequency band does an ILS glide slope operate?

Answer 6

UHF

Question 7

Explain how the ILS(glide slope and localiser) can guide an aircraft to the runway?

Answer 7

Two lobes of varying frequency is transmitted, 90Hz for the upper lobe and 150Hz for the lower lobe in the case of a glide slope. 90Hz for the left side lobe and 150Hz for right side in the case of a localiser. If the aircraft receives more of the one frequency than the other it must be deviating from the desired profile. The desired profile being where the varying frequencies are equal in amount received.

Question 8

Full deflection of the localiser(per side) is -

Answer 8

2.5° from the runway centreline

Question 9

OBS setting:

With a primitive VOR/ILS instrument, the OBS setting -

But newer flight director systems -

Answer 9

will not function, it is automatically set on the runway QDM.

The runway QDM need to be manually set