As the dry season nears, the Nigerian Civil Aviation Authority (NCAA) has issued a weather alert to all pilots informing them of hazards associated with harmattan haze during flight operations.
The director general of NCAA, Capt. UsmanMuhktar, said in a memo to airlines that the warning became necessary as harmattan is known to pose obvious threat to aircraft particularly in areas of challenging terrains due to low visibility.
“This alert is in line with the seasonal rainfall prediction issued by the Nigerian Meteorological Agency (NIMET) on the cessation of rainy season in 2014. The harmattan is a dry and dusty wind that blows southwards from the Sahara across the country between the end of November and March the following year.
“On its passage over the desert, it picks up large amount of fine dust particles (0.5 to 10 micrometers) which is transported hundreds of kilometres over the south. The effect of the dust and sand stirred by the wind is known as harmattan dust haze. In addition, the consequence of the harmattan is a heavy fog hence air-to- ground visibility is considerably reduced.
“Aerodrome visibility may fall below the prescribed minima and in severe conditions; dust haze can blot out runways, the markers and airfield lightings over wide areas. This makes visual navigation extremely difficult or impossible. Consequently, where visibility falls below the prescribed weather minima, flight operations are likely to be delayed, diverted or out rightly cancelled.
“Therefore, all pilots shall obtain adequate departure, en route and destination weather information and briefing from NIMET prior to flight operations at all the airports. Pilots are similarly advised to exercise maximum restraint when strong surface wind, fog or harmattan haze is observed or forecast,” said Muhktar.
