User Guide

Learning To Fly with Rod Machado

149

Tutorial 15: Flying an ILS Approach

Are you ready to rock and roll? If you thought VOR approaches were fun,

wait till you get hooked on flying the instrument landing system (ILS)

approach. It’s perhaps one of aviation’s most challenging, yet satisfying,

aerial activities.

Don’t forget to do the homework—the last homework of our class. Gets

you a little teary-eyed, doesn’t it?

An ILS approach consists of a descent to a runway with both vertical and

horizontal electronic guidance. It’s accomplished by following two needles

(Figure 1) located in the ILS display (which is the same instrument as the

VOR 1 indicator) on your instrument panel. Unlike other instrument

approaches, this one takes you down to a height known as decision height (DH), also referred to as

decision altitude (DA). DH is approximately 200 feet above the runway elevation as shown in Figure 2.

From this not-too-lofty perch, you can take a

peek outside and decide if you can see the

runway well enough to land. If unacceptable

runway visibility prevents a safe landing, you

apply power, climb, and head off to someplace

else with better weather. Let’s take a closer look

at how the ILS approach is constructed.

Two Beam or not Two Beam

The ILS consists of two electronic beams. One

beam is angled outward and one is angled

upward from the runway complex as shown in

Figure 3. The outward (horizontal) beam is

called the localizer. It helps align your airplane

with the runway. You track the localizer by

following the needle shown in Figure 1 (position

A). If the needle is to the right, you go to the

right; if the needle is to the left, you go to the

left. A needle that remains centered means your

Figure 1

Figure 2

Figure 3