BY KIRAN BIRADAR

Aviation infrastructure

planning

Day and Night LANDING AIDS

Landing aids: Any illuminating light radio

beacon, radar device communicating

device or any system of such devices for aiding aircraft in an approach and landing.

Used to guide a pilot to the runway , helps the pilot to judge his alignment with the runway and correct angle of approach

Various landing aids

Instruments landing system (ILS) Precision approach radar (PAR) or ground

approach control (GAC) Airport surveillance radar (ASR) Airport surface detection equipment

(ASDE) Approach lights

Instruments landing system (ILS)

Instrument landing system (ILS) was the only ground-based system certified to provide both lateral and vertical guidance to aircraft on approach to an airport.

An ILS system consists of two radio transmitters located on the airport.

One radio beam is called the localizer and the other the glide slope.

The localizer indicates to pilots whether they are left or right of the correct alignment for approach to the runway and the glide slope indicates the correct angle of descent to the runway

Cont… ILS system provides facilities for landing

under conditions of poor visibility.ICAO has divided the visibility into three

categoriesfor ILS approach:Category I Covers the weather conditions which

provide a forward visibility of at least 800 m

Category II Allows the landing up to a forward visibility of 400 m

Category III Permits landing under 0 (zero) visibility conditions.

ILS system configuration

Precision approach radar (PAR) or ground approach control (GAC)

Same as ILS but the information reaches the pilot through his hearing aid.

PAR gives to the controller picture of descending aircraft both in plan and elevation then controller checks the alignment and glide slope of aircraft.

So no need of navigational equipment.

Used for military aircrafts.

Airport surveillance radar (ASR)

ASR provide air traffic controllers with a visual display of the position of each aircraft within the air space surrounding the terminal.

Effective up to a distance 50 km to 100 km.

It does not indicate the altitude of the aircraft.

In INDIA this is provided at Jawahar lal Nehru (Mumbai) and Subhash chandra bose (Calcutta) airports.

Airport surface detection equipment (ASDE)

ASDE is a short range radar which gives to the controller a pictorial display of the runways , taxiways , terminal areas and shows the position of the aircrafts.

ASDE is very efficient in poor visibility to regulate the traffic on the airport.

ASDE is able to determine the position and identification of aircraft and vehicles on the airport surfaces, as well as of aircraft flying within 8 km of the airport.

An ASDE display showing ground traffic at Hartsfield-Jackson Atlanta International Airport

Approach lights system(ALS)

ALS is a lighting system installed on the approach end of an airport runway and consisting of a series of light bars, strobe lights, or a combination of the two that extends outward from the runway end.

Approach lighting systems (ALS) are designed specifically to provide guidance for aircraft approaching a particular runway under nighttime or other low-visibility conditions.

Calvert system: The Calvert system was the first approach lighting system to be

certified by ICAO, and is also commonly known as the ICAO category I approach lighting system.

ICAO CAT II-III approach lighting system

The ALS currently certified by the FAA for installation in the United States consist of a high-intensity ALS with sequenced flashinglights (ALSF).

This is required for category II and category III.

High-intensity approach lighting system is consist of Sequenced flashing lights (ALSF-1) Three medium-intensity ALSs (MALSR, MALS,

MALSF).