Sunday, April 12, 2009

Construction activity at airport creates dust pollution, lowers visibility

Construction activity at airport creates dust pollution, lowers visibility
There is a flurry of activity in Chennai airport's backyard across the Adyar river where work is on to extend the secondary runway. A pall of dust hangs in the air as hundreds of trucks dump soil and earth movers level the barren tract of land. All this is preliminary work in the laying of taxiways and the construction of an apron and other facilities.

The pall of dust is creating problems, not only for aircraft operations but also for residents in neighbouring Manapakkam, Tarapakkam and Porur who are trying to battle pollution. Although the impact of dust on aircraft and on the airport itself has not been studied yet, experts say that too much of dust near the runway is not a good thing because it affects visibility. Already, a combination of dust and high humidity has been creating early morning fog, bringing down visibility levels considerably. "Instances of low visibility at the airport have been increasing over the years, from less than 5 days in a year the 1970s to more than 20 days now.

The dust and pollution caused by the emergence of residential neighbourhoods is one of the reasons. Our staff assessing visibility has reported the sudden formation of fog in the hours before dawn," says an official of the airport meteorological department. "There is also a brick kiln that could be raising dust. We are planning to investigate," he adds. In the past few weeks, visibility has dipped dramatically from 4,000 metres, reducing to 40 metres on March 6.

Chennai airport does not have a Runway Visual Range (RVR) instrument, which makes matters worse. "Air-side vehicles coming close to the aircraft also cause trouble and can be considered one of the reasons for technical snags," says a directorate general of civil aviation official. However, TIFAC CORE (expansion??) director of Hindustan University N S Venkatraman says that dust is not a major irritant for aircraft although it affects visibility drastically.

Says retired pilot Captain A Ranganathan: "Dust normally causes minimal problems to aircraft. Dust settling on aircraft causes extra drag and leads to high fuel use." He adds that if the electronics bay is kept open for a long time during or after maintenance, it will cause electronics failure. "The Amsterdam crash happened after the radio altimeter failed, probably because of dust infiltration. But I have not seen such systems failing in India because of dust-related problems. Runways often have rubber and oil deposits. So, if dust settles on the runway, even a slight drizzle makes it slippery. Unless the airport removes rubber deposit frequently, safety will be compromised.

" An aircraft engineer says that maintenance should be time-bound and carried out for all aircraft. "There is a maintenance time frame for each part, including hydraulic systems and fluid checks. The deadlines must be kept." An Airports Authority of India official says that dust-control measures such as sprinkling of water is on. "We are bringing partially wet soil for laying the secondary runway so that not much of dust is kicked off," he said.

The Met department at the airport does not have access to pollution statistics produced and monitored by the Central Pollution Control Board. "If we have access to the data we can forecast dip in visibility," the official said. An International Civil Aviation Organisation (ICAO) document says that non-airport related activities such as road vehicles accessing the airport and operating near roadways, air-side vehicles, as well as the geographical area are relevant to assessment under the national regulatory scheme.


http://timesofindia.indiatimes.com/Chennai/Construction-activity-at-airport-creates-dust-pollution-lowers-visibility/articleshow/4363400.cms

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