CHAPTER ONE

INTRODUCTION1

.1. BACKGROUND TO THE STUDYAviation probably more than any other mode of transportation is tremendouslyaffected by weather. Every phase of flight operation that is from the take off to thelanding and also  when aircraft is in-flight hasthe potential  to be influenced byweather (Kulesa, e2013). Aircraft   travels   through   the   atmosphere.   The   atmosphere   varies   vertically   andhorizontally   in   pressure,   temperature,   density   and   atmospheric   humidity.   Itcontains quantity of water vapour, which when condensed produce a gaseous fogand   continues   like   that   to   cloud,   sleet,   hail   and   precipitation   all   which   affectvisibility (Oliver, 1997). Safety and efficiency of air traffic may be affected byweather   phenomenon   such   as   reduced   visibility,   turbulence,   wind   shear,thunderstorm particularly at the terminals of an airport, results in delays, diversion,cancellation of flight and reduced Airport capacity as well as accident (Oliver,1997).“Flight operations” is such a generalized term which encompasses many things inthe aviation operations, and that definition given to this term is based on Airlines ata local station of operation. This deals with flight and aircraft dispatch, flight crew1

and flight watch. Flight operations refer to the agents who perform weight andbalance functions for flight transiting their city for many airlines, at a local station.However, it is most acceptably defined, as the central decision-making center forthe airline that handles flight (Civil Aviation Forum, 2001 and 2005). The aircraftflight section constitutes three important phases of flying which are; take off, inflight and landing. Of these, landing has been observed to be the most difficultphase   of   flight   operations,   followed   by   takeoffs.   Studies   have   shown   that   inaviation, 80% of all aviation accident occur shortly before, after or during takeoffor landing, and often described as resulting from “human error”. For example, theinvestigation into the crashes of Bellview and Sosoliso airlines in 2005 and ADCairline in 2006 in Nigeria were reported to occur between takeoff and landing andcaused   by   wind   shear   (variation   in   local   wind   speed   and   direction)   however,induced by human error (All Africa Global Media,  2005 and Ayigbe, 2006). Thisresearch work is focused on this aircraft aspect of the flight operation.Visibility is one of the major climatic element, which affects all forms of trafficfrom road to aviation. It is the most obvious weather parameter that affects aircraftoperations (Hughes, 1982).Weather continues to play a significant role in numberof aviation accidents and incidents. While National Transportation Safety Board(NTSB) reports most commonly find human error to be the direct accidents caused,2

weather is a primary contributing factor in 23 percent of all aviation accidents(Kenneth and Libbrecht, 2001). There are many definition of visibility by various authors ( Aremu,2014; Ayode,1998; Dick, 1990  and others).  All these  definitions  are saying the same  thing.According to Aremu (2014), visibility is the greatest horizontal distance at which asuitable   object   can   be   seen   and   recognized   with   the   unaided   eye.   The   wordhorizontal is very important in that there may be mist or fog in a small nearbyvalley which may block the observers view. Visibility is measured by references toobjects or lights whose distance from the observation is known (Seinfeld et al,2006).Visibility has different names based on distances of occurrence in meteorology.Aremu (2014) classifies the types as fog which is less than 1km and mist which isbetween 1-2km.According to Seinfeld et al (2006), Fog and  mist are generallyassumed to be composed principally of water droplets. Haze and smoke can be ofsmaller particle size.Visibility is very important for the pilot controlling an aircraft on flight conditionsclose to the ground particularly when landing or take off. The natural view of thepilot   is   dependent   on   various   meteorological   conditions   close   to   the   groundparticularly when landing or take off. In addition, the natural view of the pilot is3

dependent on various meteorological conditions such as darkness, dust, fog andrainfall which is the major causes of flight cancellations, diversions, delay orevenaccidents (Middleton, 1995). Low visibility can be caused by different weatherparameters;   these   are   rainfall,   thunderstorms,   fog,   and   thick-dust   haze.   Liquidvisibility   and   fog   account   for   most   low   visibility   in   Murtala   MuhammadInternational Airport, while thick dust haze can restrict visibility and making itdifficult for landing and take – off of extremely danger.1.2STATEMENT OF THE RESEARCH PROBLEM It was reported by Ayigbe (2007) that the civil aviation practice in Nigeria hascome to the front burners in recent years because of the fear to fly as a result of thecountless plane crashes thathad drummed up public debate on the safety of livesand property.  The  crashes  of  ADC,   Sosoliso,  Dornier  288  (military),  Bellviewaircrafts among others has safely placed Nigeria as one country with worst safetyrecord in the preceding years, and this has resulted in Nigeria been ranked numberfour  (4) in the  world coming  after  Congo, Uganda and Tanzania  in  air  trafficdisaster.   One   of   the   reasons   given   by   the   then   Minister   of   Aviation   to   beresponsible for the rampant accidents and incidents was that reports from flightoperators, especially Pilots indicated that weather reports were highly unreliable4

for safe navigation. Therefore, the Minister called on the Nigerian MeteorologicalAgency (NIMET) to improve in the year 2007.The problem being envisaged in finding solutions to the rampant air disaster inNigerian  airspace  by the aviation authority is  the  negligence  in addressing  theweather factors identified among the causative factors. This is because when airdisasters   occur   blames   are   being   apportioned   to   the   human  and   the   economicfactors with little or nothing been said about the weather (natural) factors, such aswind shear, visibility, heavy rainfall, crosswind (strong wind) and over flooding.For instance, reports by Shadare (2005) shows that on 11 June 2005, an EAS planeovershot its runway by 40 meters in Jos airport before being stuck in mud due toinclement (severe)  weather. Day after this, Chanchangi airliner, B727 similarlyovershot   the   runway   by   about   100   meters   before   been   stopped   by   a   drainagechannel in Lagos airport due to over flooding, as a result of the day’s rainfallwhich rendered the plane brakes ineffective. In addition, an EAS plane hoveredover the airport for more than two hours before landing due to flooding from heavyrains. Instead of looking at the real cause of the accidents, the then Minister ofAviation suspended the Pilots of the two planes. In addition, the recommendationsgiven to address the situation were the maintenance of aircrafts, routine check ofthe planes, pilot’s exposure to more training and refresher courses and lighteningof the runway without looking into the real cause of theaccidents. Based on these