ILS and MLS

Question 1

ILS provides guidance in

Answer 1

Azimuth and elevation

Question 2

LOC freq band and no of channels

Answer 2

VHF
108.00 to 111.95 MHz
40 channels

Question 3

GP/GS freq band

Answer 3

UHF

334.7 to 330.95 MHz

Question 4

Localiser position

Answer 4

Opposite end of the r/y

Question 5

How does the localiser work

Answer 5

Looks for the DDM (difference in depth modulation) - increases away from the centre line where it is 0

Question 6

Blue lobe

Answer 6

150 Hz

Question 7

Yellow lobe

Answer 7

90 Hz

Question 8

Localiser coverage

Answer 8

At 25nm - 10* either side of the centre line

At 17nm - 35* either side of the centre line

Question 9

Glidepath antenna location

Answer 9

300m beyond the threshold

120m to the side of the centreline

Question 10

Glidepath coverage and formulas for upper and lower limits

Answer 10

10NM - 8* either side

Upper limit = 1.75 x theta
Lower limit = 0.46 x theta

Question 11

Steep approach

Answer 11

4.5* + above

Question 12

To find false beams on a glideslope

Answer 12

Multiple of the glideangle

E.g for a 3* - the first would be at 6*