ANNAMACHARYA INSTITUTE OF TECHNOLOGY AND SCIENCES NEW BOYANAPALLI, RAJAMPETA A TECHNICAL SEMINOR ON INSTRUMENT LANDING SYSTEM

PRESENTED BY

K.DINESH REDDY

14705A0405

II ECE-A

OUTLINES

WHAT IS ILS USES OF ILS ILS ELEMENTS HOW LOCALIZER WORKS HOW GLIDE PATH WORKS MARKER BEACONS ADVANTAGES OF ILS CONCLUSION

WHAT IS ILS

ILS stands for instrument landing system

It has been existence for over 60 years.

But today, it is still the most accurate approach and landing aid that is used by the airliners.

HISTORY OF ILS

The first scheduled passenger airliner to land using ILS was in

1938.

USES OF ILS

The main purpose of ILS is safe landing of aircrafts

To guide the pilot during the approach and landing

It is very useful under zero visible conditions such as rain ,snow and night times .

Scheduled service would be impossible without a way to land in poor weather.

POOR VISIBILITY LANDINGS

Localizer and Glide Path antenna located at aircraft nose receives both signals and sends it to ILS indicator in the cockpit.

These signals activate the vertical and horizontal needles inside the ILS indicator to tell the pilot either go left/right or go up/down.

By keeping both needles centered, the pilot can guide his aircraft down to end of landing runway aligned with the runway center line and aiming the touch down.

HOW ILS WORKS

ILS COMPONENTS

Localizer (horizontal guidance)

Glide path (vertical guidance)

Marker Beacons (height aircraft)

9

ILS COMPONENTS

Localizer

Glide PathMarker beacons

ILS INDICATOR

Localizer

Deviation

from

runway

centre line

Glide pathDeviation

from optimal

glide path

“Dots”Each “dot” on

the instrument

represents 2° of deviation

HOW DOES LOCALIZER WORKS

Localizer provides the information about the position of the aircraft

Whether it is flying to the right side of the runway or left side of the runway or center of the runway

Localizer is located at 300mts from the runway

Localizer is operated at a frequency of 108Mhz-112Mhzs

Localizer transmitts two signals of90hz & 150hz with same modulation index

HOW DOES LOCALIZER WORKS

For example, if an aircraft is flying to the right side of the runway, the 150hz signal is stronger

If the aircraft is flying to the left side of the runway, the 90hz signal is stronger

When the aircraft is along the centre line of the runway, the two signals gets cancelled and zero position indicates on the ILS indicator

HOW LOCALIZER WORKS

Right

Left

HOW GLIDE PATH WORKS

By the help of glide path aircraft is following the correct path when landing

It is operated at a frequency i.e. 330Mhz

If an aircraft is flying above the glide path, then the 90hz signal is stronger

If an aircraft is flying below the glide path, then the 150hz signal is stronger

The combination of both localizer and glide path equipment provides sufficient information to the pilot for safe landing

A common indicator is used for both units

HOW GLIDE PATH WORKS

GLIDE PATH

Needle indicates

above/below glide path.

Centered Needle =

Correct Glide path

MARKER BEACONS

Marker beacons are used for height checking and provides distance between aircraft and runway

Marker beacons are arranged at different points

Each beacon allotted a audio code(tone) to indicate distance from the runway to alert the pilot for safe landing

The most accurate approach and landing aid that is used by the airliners.

ADVANTAGES OF ILS

CONCLUSION :

•Instrument Landing System is necessary for all airports for safe landing of aircrafts under any conditions like rain , fog , moisture and during nights etc.

21

QUERIES ?....