Delhi International Airport Out of the Mist

9 March 2010 (Last Updated March 9th, 2010 18:30)

Every winter Delhi endures dense fog for periods lasting up to 15 hours. Future Airport talks to Delhi International Airport (DIAL)’s PS Nair about the lighting technologies the airport uses to reduce fog-induced delays and cancellations.

Delhi International Airport Out of the Mist

Future Airport: How serious are problems with fog at Delhi Airport?

PS Nair: During the winter, Delhi’s Indira Gandhi International Airport (IGIA) is enveloped in dense fog for an average of ten to 15 days each time. This causes visibility to drop below 50m, (CAT III C conditions) lasting approximately ten hours, thus affecting airport operations. IGIA has two CAT III B ILS-compliant runways enabling aircraft to take off at visibility over 150m and landing above 50m. This also allows all aircraft with CAT III B-trained pilots to land even when the runway visual range (RVR) is up to 50m. IGIA is the only airport in India to feature CAT III B ILS. Additionally, 55 parking bays, including 36 at the domestic aircraft apron, have been provided with CAT III-compatible lighting systems. Recent modifications have provided additional taxi routings to ease aircraft movement and prioritise the movement of CAT III-enabled aircraft. DIAL has also adopted other fog-relief measures (see Fog-relief measures at IGIA).

"IGIA has two CAT III B ILS-compliant runways enabling aircraft to take off at visibility over 150m and landing above 50m."

At what time of year do problems with fog usually occur?

Fog generally starts from the last week of November and ends by mid-February. Last year there were very few occasions when we had cancellations, delays or flight diversions.

Please describe the building projects currently underway at the airport.

DIAL is constructing the world’s seventh-largest integrated Terminal 3, which will be spread over 0.52 million square metres. The salient features of Terminal 3 are as follows:

  • a capacity to handle 34 million passengers per year
  • 78 aerobridges
  • 168 check-in counters
  • 90 travelators for intra-terminal transport
  • a high-speed, dedicated rail link from the city centre to the airport with a check-in facility at the city centre
  • an eight-lane approach road to the terminal
  • multilevel car parking for more than 4,000 cars
  • restaurants, shopping and recreation facilities
  • comfortable airport hotels and lounges to suit every budget.

How will these projects enable the airport to better deal with fog?

Terminal 3 will provide a large retail space, lounges and hotel rooms for departing passengers waiting because of delays due to fog.

"The new system fully supports continued flight operations and ground movement of aircraft during periods of low visibility."

Why has the CAT III system not eliminated the airport’s problem with fog-induced delays?

The CAT III B ILS System can only allow compatible aircraft and trained pilots to land when RVR is above 50m. If visibility drops below this point we cannot allow aircraft to land or depart on/ from the runway.

What new lighting technologies have you put in place?

We have equipped Runway 11/29 with the Category III Airfield Ground Lighting System, based on advanced lighting technologies and a fully computerised control and monitoring system. We shall be upgrading the lighting system of Runway 10/28 to a similar standard by the next year or so.

How will the new lighting technology reduce flight cancellations and delays?

The new system fully supports continued flight operations and ground movement of aircraft during periods of low visibility (when RVR is as low as 50m), which considerably reduces flight cancellations and delays.

How do you decide which technologies to use?

Our selection of the lighting technologies is based on the performance standards laid down by International Civil Aviation Organisation and practices followed in US, European and Australian airports.

Who are your key suppliers for lighting technologies?

Based on a competitive bidding system, we selected Honeywell (Germany) to handle the major part of our lighting system and SafeGate (Sweden) supplies for visual docking systems.

In tackling these issues have you learnt any lessons from other airports?

While planning and designing the airfield support systems our experts have studied the operating features of similar systems functioning optimally and satisfactorily at many airports in the US, Europe, Canada, Australia and South Korea.

Do you expect the airport to be better equipped to deal with fog in time for the 2010 Commonwealth Games?

Although we don’t expect fog during October 2010, IGIA will ensure that all its three runways and the brand new integrated Terminal 3 will be operational to deal with any fog situation.