Statistics of low Visibility days over the Osvaldo Vieira Bissau International Airport, during period 2007-2016

Visibility is one of the major climatic factors which affect all forms of traffic, from road to aviation. It is the most obvious weather parameters that affect aircraft operations (Hughes, 1982).Weather continue to play a significant role in number of aviation accident and incident. Weather parameters seems to be the main factor of plane crash and other accident in aviation industry, bad weather contribute to about 70% of the plane crash incident which causes loss of lives and properties (ICAO Annex 10, 2010). For example Russian passenger plane crashed in heavy fog and exploded in flames after slamming down short of the runway, killing 44 and critically injured 8 people (Sani, 2010). Result of a recent research from the United State of America shows that, the total weather impact is an estimated national cost of about $ 3 billion for injuries, delays and unexpected operating costs (Kulesa et al, 2013). Guinea Bissau is a nation which has many functional sectors not properly managed; IOVBA is not left out. Several studies have been carried out- Kulesa, et al (2013), Qualley (2013), Kalu (1998), Kenneth and Libbrecht (2001), Ephraim, (2012), Sani, (2010) Kabir, (2010) aimed at addressing the impact of weather on flight operations. These studies however tend to consider on the ground effects particularly when landing and take – off. That is the reason why (Middleton,1995) stressed that poor visibility yields natural view of the pilot is dependent on various meteorological conditions such as darkness, dust, fog, hail, and rain which are the principal cause of flight cancellation, diversion or delays.

Thus weather information is therefore critical to aviation safety. Indeed aviation is perhaps the earliest industry to use weather information on to operational decision making. Therefore this study will give flight operators and passengers a service of safety. The research will also identify the weather parameters (rain, fog, thick-dust and haze) which affect visibility. The study will also give out period that are mostly affected by poor visibility. The findings of this work will help to understand how visibility affects landing and takeoff of aircraft, so as to ensure safety outcomes of flight. It will also serve as a form of resources materials for future researchers and also there is need to properly address these issues in order to move the aviation industry forward.