ILS Approach

Question 1

What are actions/considerations if any of the components of the ILS fails?

Answer 1

• If the localizer is not available then no ILS or LOC approach is possible (missed approach)
• If the glide slope is not available, a localizer approach may be conducted to the LOC minima specified (MDA)
• If marker beacon(s) fail/don’t exist an approach to the published ILS minima may be made if a DME is available and DME/ALT fixes are published on the plate
  -If HIAL is not available, the ILS visibility minimum increases to 1,500 m. Additionally, the visibility minimum for any non-precision approach, including LOC, to a runway equipped with HIAL must be increased by 900 m if the lights are unavailable.
• If HIRL is not available, the CAT I ILS visibility minimum (if applicable) increases to 1,200 m.

Question 2

Does an localiser approach use an MDA or a DH?

Answer 2

Localiser uses an MDA, ILS used a DH

Question 3

You are on approach and pass the DH but only have the HIAL in sight, can you continue the approach?

Answer 3

Yes, you are in sight of the “runway environment”

Question 4

Does a localiser approach use an MDA or a DH?

Answer 4

Localiser uses an MDA, ILS used a DH

Question 5

What should you see at the DH of an ILS when the visibility is 800m, 1000m and 1200

Answer 5

800m - See the HIALs
1000m - See the threshold
1200m - See the PAPIs