IM P A C T S O F R A IN F A L L O N A IR C R A F T O P E R A T IO N S A T J U L IU S N Y E R E R E IN T E R N A T IO N A L A IR P O R T A N D S H IN Y A N G A A IR P O R T , T A N Z A N I A // BY A L L Y S. M U S S A 145 / 6 0 0 2 5 / 2 0 0 9 P G D IN M E T E O R O L O G Y S U P E R V IS O R S ; D R J .M . I N I N D A AND D R R .E . O K O O L A A R E S E A R C H R E P O R T S U B M I T E D IN P A R T I A L F U L F IL L M E N T O F T H E R E Q U IR E M E N T S F O R A W A R D O F A P O S T G R A D U A T E D I P L O M A ( P G D ) IN M E T E O R O L O G Y , U N IV E R S IT Y O F N A IR O B I. S E P T E M B E R , 2002University of NAIROBI Library D E D IC A T IO N : T h is p ro je c t w o rk is d e d ic a te d to th e e n tire m e m b e rs o f m y fa m ily fo r th e ir e n d le s s s u p p o rt a n d e n c o u ra g e m e n t th ro u g h o u t m y stu d y . W e re it n o t fo r th e ir su p p o rt, I w o u ld n o t b e w h e re a n d w h o I am to d a y . 2 D E C L A R A T IO N ; I d e c la re th a t th is p ro je c t is m y o w n w o rk an d h a s n o t b e e n s u b m itte d to an y o th e r in s titu tio n s fo r th e a w a rd o f d ip lo m a in M e te o ro lo g y , o r B a c h e lo r o f S c ie n c e (B S c ) in M e te o ro lo g y , o r a n y o th e r d e g re e c o u rse . T h e p ro je c t w a s c a rrie d o u t an d p re s e n te d fo r E x a m in a tio n by: ^ ..... o f 2009 (D a te ) (S ig n a tu re ) A L L Y S. M U S S A T h e p ro je c t h a s b e e n s u b m itte d fo r E x a m in a tio n w ith o u r a p p ro v a l a s U n iv e rs ity S u p e rv iso rs: ...o n ... C fc tv (S ig n a tu re ) .2 0 0 9 (D a te ) D R J .M . IN IN D A on of.. (D a te ) (S ig n a tu re ) D R R .E . O K O O L A 3 2009 TABLE OF CONTENTS D e d ic a tio n ................................................................................................. ii D e c la ra tio n ................................................................................................ iii A b s t r a c t ........................................................................................................ iv C H A P T E R O N E ........................................................................................... 7 1.0 1.1 I n t r o d u c t i o n .......................................................................................... 7 S ta te m e n t o f p r o b l e m ........................................................................... 7 1.2 R a in fa ll c lim a to lo g y o f s tu d y a r e a ....................................................... 8 1.2.1 A re a o f s t u d y ........................................................................................ 8 1 .2 .2 M a jo r sy n o p tic C i r c u l a t i o n .................................................................. 8 1.3 1.3.1 1 .3 .2 1.4 1.5 1.6 O b j e c t i v e s ........................................................................................... 11 G e n e ra l o b j e c t i v e s ............................................................................... 11 S p e c ific o b j e c t i v e s ...............................................................................11 S c o p e o f s t u d y .................................................................................... 12 S ig n ific a n c e o f s t u d y ........................................................................... 12 L ite ra tu re r e v i e w ................................................................................. 12 2 .0 C H A P T E R T W O ; D A T A A N D M E T H O D O L O G Y ..........................15 2.1 D a ta , D a ta s o u rc e s a n d D a ta q u a lity c o n t r o l ...................................... 15 2 .1 .1 2 .1 .2 2 .1 .3 2 .2 2 .2 .1 2 .2 .2 2 .2 .3 D a t a .....................................................................................................15 D a ta s o u r c e s .............. 16 D a ta q u a lity c o n t r o l .............................................................................17 M e t h o d o l o g y ....................................................................................... 18 T im e s e rie s a n a l y s i s ........................................................................... 18 G ra p h ic a l m e t h o d ................................................................................ 19 C o rre la tio n a n a l y s i s .............................................................................19 3 .0 C H A P T E R T H R E E ; R E S U L T S A N D D IS C U S S IO N S ..................... 20 3.1 R e s u lts fro m T im e s e rie s A n a ly s is ................................. 3.1.1 S e a s o n ra in fa ll (M A M ) A n a ly s is ...................................................... 20 3 .1 .1 .1 J N IA s e a s o n ra in (M A M ) A n a ly s is ................................................. 20 3 .1 .1 .2 H T S Y s e a so n ra in (M A M ) A n a ly s is ......... ..................................... 21 3 .1 .2 M o n th ly ra in fa ll d a ta A n a l y s i s ........................................................ 22 3 .1 .2 .1 J N IA M o n th ly ra in fa ll d a ta A n a l y s i s .............................................. 22. 3 .1 .2 .2 H T S Y M o n th ly ra in fa ll d a ta A n a l y s i s ............................................ 24 3 .1 .3 D a ily ra in fa ll d a ta a n a l y s i s .............................................................. 2 6 4 3 .1 .3 .1 J N IA O n se t a n d C e s s a tio n fro m P e n ta d ra in fa ll d a t a ................... 26 3 .1 .3 .2 H T S Y O n s e t a n d C e s s a tio n fro m P e n ta d ra in fa ll d a t a ..................... 27 3 .2 3 .2 .1 R e s u lts fro m G ra p h ic a l m e th o d (h is to g ra m ) A n a ly s is ........................ 29 J N IA A irc ra ft o p e ra tio n s d a ta A n a ly s is ............................................ 29 3 .2 .2 H T S Y A irc ra ft o p e ra tio n s d a ta A n a ly s is ............................................ 32 4 .0 C H A P T E R F O U R ; C O N C L U S IO N S A N D R E C O M M E N D A T IO N S ..37 4.1 C o n c l u s i o n s .......................................................................................... 37 4 .2 R e c o m m e n d a t i o n s ................................................................................ 37 A c k n o w le d g e m e n t s ..................................................................................... 38 R e f e r e n c e s ................................................................................................. 39 5 ABSTRACT A lth o u g h a ir tra n s p o rta tio n s e e m s to b e th e b e s t w a y o f tra v e ls in T a n z a n ia s o m e tim e s it b e c a m e u n s a fe ly a n d u n re lia b le d u e to th e d iffe re n t fa c to rs in c lu d in g b a d w e a th e r su c h as h e a v y ra in s. B a d w e a th e r m a y le a d to a irc ra ft a c c id e n ts , d e la y s, c a n c e lla tio n s o f flig h t, a n d d iv e rs io n s o f f lig h ts to o th e r a lte rn a te a e ro d ro m e s . T h e p re s e n t stu d y e x a m in e d th e im p a c ts o f ra in fa ll o n a ir tra n s p o rta tio n at J u liu s N y e re re In te rn a tio n a l A irp o rt (JN IA ) an d S h in y a n g a a irp o rt (H T S Y ). T h e m e th o d s th a t w e re e m p lo y e d in th is s tu d y in c lu d e ; tim e s e rie s a n a ly s is, g ra p h ic a l a n a ly sis a n d c o rre la tio n a n a ly s is th a t u se d to S tu d y th e im p a c ts o f rain fa ll o n a ir tra n s p o rta tio n a t J u liu s N y e r e re In te rn a tio n a l A irp o rt a n d S h in y a n g a a irp o rt. In o rd e r to a rc h iv e th is o b je c tiv e th e fo llo w in g s p e c ific o b je c tiv e s w e re a d d re s s e d ; to e x a m in e th e te m p o ra l c h a ra c te ristic o f ra in fa ll a t J N IA , to id e n tify c a s e s o f d e la y in g , c a n c e lla tio n , d iv e rs io n s o f flig h ts d u e to h e a v y ra in fa ll a n d to s tu d y th e w e t sp e lls d u rin g a w e t se a s o n (In tra S e a so n a l O s c illa tio n s -IS O ). T w o d a ta se ts w e re u se d in th is s tu d y ; R a in fa ll d a ta a n d c h a rts o f e a c h d a y fo r th re e m o n th s , M a rc h , A p ril, a n d M a y fro m 199 6 to 2 0 0 5 a n d F lig h t a c c id e n t re p o rts w h ic h o b ta in e d th ro u g h a c c id e n ts re p o rt file s in o p e ra tio n o ffic e o f P re c is io n A ir. R a in fa ll a n a ly sis u s e d in th is s tu d y s h o w s th a t; T h e w e tte s t se a s o n w a s 2 0 0 2 fo r b o th s ta tio n s(J N IA a n d H T S Y ) w h ile d rie s t se a s o n w a s 2 0 0 3 fo r J N IA a n d 2 0 0 0 fo r H T S Y . A p ril w a s th e w e tte s t m o n th at J N IA B u t M a rc h w a s th e w e tte s t m o n th at H T S Y , w h ile M a y w a s th e d rie s t m o n th a t b o th sta tio n s (J N IA a n d H T S Y ). A lso rain fa ll s e a s o n (M A M ) s h o w th a t; th e m e a n o n se t s ta rts o n 3 rd w e e k o f M a rc h at b o th J N IA a n d H T S Y , w h ile th e m e a n c e s s a tio n at J N IA is o n 4 th w e e k o f M a y a n d a t H T S Y is o n 2 n d w e e k o f M a y . M o re a n a ly s is w a s d o n e o n o p e ra tio n o f a irc ra ft o n b o th sta tio n s, a t J N IA m o re d e la y s w e re in A p ril (5 ) w h ile a t H T S Y m o re d e la y s w e re o b s e rv e d in M a rc h (6 ), a n d m a x im u m n u m b e r o f c a n c e lla tio n (3 9 ) o c c u rre d at H T S Y . A lth o u g h ra in s c a u se s o m e c a n c e lla tio n s an d d e la y s o f flig h ts, b u t it is n o t a m a in c a u s e o f a irc ra ft a c c id e n ts in T a n z a n ia . T h e re s u lts o b ta in e d fro m ra in d a ta an d o p e ra tio n o f a irc ra ft s h o w e d th e re a re m o re c o rre la tio n s b e tw e e n ra in d a y s a n d d e la y s o f flig h ts at b o th a irp o rts (JN IA & H T S Y ), a lso s o m e c o rre la tio n s a re o b s e rv e d o n ra in d a y s a n d c a n c e lla tio n s o f flig h ts a t H T S Y . In o rd e r to so lv e th e p ro b le m s o f m o s t c a n c e lla tio n s , th e c o n s tru c tio n o f p a v e d (ta rm a c ) ru n w a y s is re q u ire d ; a ls o th e p ro b le m o f d e la y s o f flig h ts c a n b e so lv e d b y re la tin g flig h ts p la n n in g w ith d a ily w e a th e r fo re c a s ts a n d T e rm in a l A e ro d ro m e s F o re c a s ts (T A F ). I 6 CHAPTER ONE 1.0 In tro d u ctio n T h e o p e ra tio n o f a irc ra fts at J u liu s N y e re re In te rn a tio n a l a irp o rt (JN IA ) fo rm a lly (D a r es sa la a m In te rn a tio n a l A irp o rt) a n d S h in y a n g a A irp o rt s o m e tim e s fa lls u n d e r risk b e c a u s e o f h e a v y ra in (+ R A ), h e a v y th u n d e rs to rm w ith ra in (+ T S R A ) w h ic h a re a lw a y s a ss o c ia te d w ith s tro n g w in d , th e th u n d e rs to rm w ith h e a v y ra in s re d u c e s v e rtic a l a n d h o riz o n ta l v isib ility . A irc ra fts a c c id e n ts w h ic h o c c u r d u rin g la n d in g a n d ta k e - o f f s ta g e s in m o st a e ro d ro m e s a re c a u s e d b y e ith e r s e v e re w e a th e r o r te c h n ic a l p ro b le m s in a irc ra ft itself. H e a v y R a in fa ll is a m a jo r c a u se o f a c c id e n ts as it c a n re d u c e s v isib ility u p z e ro , th is m a k e s it d iffic u lt fo r p ilo ts to see th e ru n w a y c le a rly , i f p ilo t d e c id e to ta k e o f f o r la n d in g in s u c h c o n d itio n it c a n lea d to a irc ra ft c ru s h in g w h ic h resu lt in d a m a g e o f a irc ra ft a n d lo s s o f lives. A lso h e a v y ra in fa ll c a n c a u s e a c c id e n ts th ro u g h d a m a g in g a ir n a v ig a tio n sy s te m o n b o a rd th e a irc ra ft w h ic h is v e ry im p o rta n t d u rin g la n d in g o f a irc ra fts ; th e re fo re p ilo t c a n lo o s e c o m m u n ic a tio n a n d m a k in g la n d in g to b e risk y . T h e p o s s ib ility o f a n a c c id e n t to o c c u r is h ig h i f p ilo t fo rc e d to lan d in su c h c o n d itio n s. H e a v y ra in fa ll a lso c a u s e s in te rru p tio n in o p e ra tio n o f a n a irc ra ft d u e to flo o d s a n d m a in te n a n c e o n its in fra s tru c tu re su c h as ru n w a y , th is m a y le a d to d e la y o n ta k e o f f o r la n d in g , c a n c e lla tio n o f flig h ts, a n d d iv e rs io n o f flig h t to a lte rn a te a e ro d ro m e s. T h e p re s e n t s tu d y w ill c o n c e n tra te o n th e h e a v y ra in w h ic h fa lls d u rin g lo n g ra in s e a s o n o f M a rc h , A p ril a n d M a y (M A M ) in e a c h y e a r o n J u liu s N y e re re In te rn a tio n a l A irp o rt a n d S h in y a n g a A irp o rt a s th e a re a o f stu d y . T h e a im o f re s e a rc h is t o in v e s tig a te th e im p a c ts o f h e a v y ra in fa ll o n a irc ra ft o p e ra tio n at J u liu s N y e re re In te rn a tio n a l A irp o rt a n d S h in y a n g a A irp o rt. 1.1 P ro b lem sta te m e n t A lth o u g h a ir tra n s p o rta tio n s e e m s to b e th e b e s t w a y o f tra v e ls in T a n z a n ia s o m e tim e s it b e c a m e u n s a fe ly a n d u n re lia b le d u e to th e d iffe re n t fa c to rs in c lu d in g b a d w e a th e r su c h as h e a v y ra in s. B a d w e a th e r m a y le a d to a irc ra ft c ra sh in g , d e la y in g , c a n c e lla tio n o f flig h t, d iv e rs io n o f flig h ts to o th e r a lte rn a te a e ro d ro m e s. I f c ra s h in g o c c u rs it e x p o s e p a ss e n g e rs an d c re w in th e h ig h risk a n d d a m a g e to th e a irc ra ft, th e re fo re th e lo ss o f in c o m e fo r th e o w n e r o f th a t d a m a g e d a irc ra ft a s w e ll a s g o v e rn m e n t th o u g h tax e s. In T a n z a n ia m a n y c a s e s o f flig h t a c c id e n ts a re re p o rte d w h ic h a s s o c ia te d w ith w e a th e r, a lso m a n y c a s e s o f d e la y , c a n c e lla tio n o f flig h t a re still re p o rte d m u c h d u rin g lo n g a n d sh o rt ra in se a so n s. 1.2 R a in fa ll C lim a to lo g y o f th e stu d y a re a 1.2.1 A r e a o f stu d y J u liu s N y e re re In te rn a tio n a l a irp o rt (JN IA ) is th e la rg e st a n d b u s ie st a irp o rt in T a n z a n ia (c a te g o ry A ) th e re fo re it sh a ll re p re s e n t o th e r la rg e a irp o rts in th e re g io n . J N IA is lo c a te d in c o a sta l z o n e o f T a n z a n ia th e re fo re a lso it sh a ll re p re s e n t o th e r a irp o rts a lo n g th e c o a s ta l strip o f T a n z a n ia b y a s s u m p tio n s o f h a v in g th e s a m e c h a ra c te rs o f w e a th e r. S h in y a n g a A irp o rt is th e re g io n a l a irp o rt lo c a te d n e a r L a k e V ic to ria b a sin , th is a irp o rt c la ss ifie d a s c a te g o ry C w h ic h h a s u n p a v e d ru n w a y (d im e n sio n 2 0 0 0 x 3 0 m a n d its stre n g th is 5 7 0 0 k g ), n o ta x iw a y , a p ro n su rfa c e s tre n g th is g ra v e l, re s c u e a id fro m fire b rig a d e is c a te g o ry fiv e (5 ) so d u rin g ra in s e a s o n s th e p ro b le m s o f c a n c e lla tio n , d e la y in g a n d d iv e rs io n s a re c o m m o n . T h e re fo re th is a irp o rt w ill re p re s e n t o th e r a irp o rts a ro u n d L a k e V ic to ria b a sin a n d a ls o it re p re s e n ts o th e r a irp o rts w h ic h c la s s ifie d th e sa m e c a teg o ry . T h e U n ite d R e p u b lic o f T a n z a n ia is lo c a te d o n th e E a s t c o a s t o f A fric a b e tw e e n p a ra lle ls 10°S a n d 12°S a n d m e rid ia n s 3 0 °E an d 4 0 °E (F ig u re 1). It e x te n d s fro m L a k e T a n g a n y ik a in th e W e s t, to th e In d ia n O c e a n in th e E a s t; L a k e V ic to ria in th e N o rth , to L a k e N y a s a a n d R iv e r R u v u m a in th e S o u th It b o rd e rs K e n y a a n d U g a n d a in th e N o rth , R w a n d a a n d B u ru n d i in th e N o rth -w e s t, D e m o c ra tic R e p u b lic o f C o n g o to th e W e s t, Z a m b ia to th e S o u th -w e s t a n d M a la w i a n d M o z a m b iq u e t o th e S o u th . T h e J u liu s N y e re re In te rn a tio n a l A irp o rt is lo c a te d at la titu d e 0 6 .5 3 °S a n d lo n g itu d e 3 9 . 12°E, its h e ig h t a b o v e m e a n se a lev e l is a b o u t 55 m e te rs a n d S h in y a n g a A irp o rt is a b o u t se v e n (7 ) k ilo m e te rs N o rth E a s t o f S h in y a n g a to w n , it lo c a te d at la titu d e S a n d lo n g itu d e E , its h e ig h t a b o v e m e a n se a lev e l is 3 8 0 0 fee t. 1.2.2 S y n o p tic C ir c u la tio n sy ste m s th a t c o n tr o l th e c lim a te o v e r c o a sta l a rea o f T a n z a n ia in c lu d e ; ( a ) T h e In te r-T ro p ic a l C o n v e rg e n c e Z o n e (IT C Z ):T h is is a re g io n w h e re th e a ir m a s se s o rig in a tin g fro m th e tro p ic s o f c a n c e r a n d C a p ric o rn c o n v e rg e s a n d lift. T h e IT C Z g o v e rn s th e o c c u rre n c e o f w e t an d d ry se a s o n s. T h e c o n v e rg e n c e z o n e m o v e s w ith th e o v e rh e a d sun. ( b ) S y b -T ro p ic a l A n tic y c lo n e s:T h e s e a re M a s c a rin e H ig h ,S t H e le n a H ig h , A z o re s H ig h sn d T h e A ra b ia n R id g e . (c ) T ro p ic a l C y c lo n e s:T h is is lo w p re s su re c e n tre s th a t m o v e W e stw a rd o r S o u th w a rd fro m E a s te rn In d ia n O cean. ( d ) S e a S u rfa c e T e m p e ra tu re s o v e r S W In d ia n O c e a n (e ) E a s te rly W a v e s a n d M o n s o o n s . (f) T h e C o n g o A irm a s s:- • • T h is is an a irm a s s o rig in a tin g fro m m o is t a n d c o ld C o n g o F o re sts (g ) L a k e V ic to ria In flu e n c e :- , 8 T h is is a L o c a l e ffe c ts fro m L a k e V ic to ria . M e a n a n n u a l ra in fa ll ra n g e s fro m 7 3 1 m m to 1 ,7 3 3 m m w ith a m e a n o f 1 1 3 4 m m p e r y e a r u n d e r n o rm a l c o n d itio n s a n d d e p e n d in g o n th e e le v a tio n o f a p la c e fro m se a lev e l. T h e a v e ra g e d u ra tio n o f th e d ry s e a s o n is 5 to 6 m o n th s 9 D a ta fo r m o n th ly m e a n ra in fa ll at D a r e s sa laa m (J u liu s N y e re re In te rn a tio n a l A irp o rt) fo r th e last tw o d e c a d e s a re s h o w in th e ta b le 1 b e lo w ; M ONTHS A P R IL M EAN M ONTHLY R A IN F A L L (m m ) 74 83 143 273 JA N U A R Y FEBRU A RY M ARCH MAY 152 JU N E 34 JU L Y 32 AU GUST 28 SEPTEM BER 26 OCTOBER 60 NOVEM BER 122 DECEM BER 108 TO TAL 1134 T a b le 1; M e a n m o n th ly ra in fa ll fo r D a r e s sa laa m A irp o rt T h e fo llo w in g h isto g ra m is fo r th e m o n th s fro m J a n u a ry u p t o D e c e m b e r v e rs u s m o n th ly m e a n ra in fa lls o f J u liu s N y e re re In te rn a tio n a l A irp o rt (J N IA ), th e d a ta w a s o b ta in e d as an a v e ra g e o f tw o p a st d e c a d e s. 10 DAR ES SALAAM MEAN M O NTHLY RAINFALL(MM) < a: > MEAN MONTHLY RAINFALL (mm) _i x o 5 2 < LU 5 ^ NV ■$ $ ^ ^ > & (S ' <cf W W ° v > / & .J ' ° M ONTHS F ig u re 2; M e a n m o n th ly ra in fa ll (m m ) p lo t fo r D a r es sa laa m . W h ile T a b le 1 an d F ig u re 2 a b o v e s h o w th e rain fa ll c lim a to lo g y o f D a r e s S a la a m is b im o d a l (M A M an d O N D ), b u t M A M s h o w s th e h ig h e s t ra in fa ll c o m p a re d to O N D . N o te d th a t m e a n m o n th ly ra in fa ll is g re a te r th a n 1 0 0 m m fo r all M A M m o n th s. T h e s e m o n th s a re c la ss ifie d a s h ig h rain fa ll m o n th s. ( O k o o la a n d A m b e n je , 2 0 0 3 ). T h e re fo re th is w ill ju s tify th e u s in g o f M A M in m y re s e a rc h a s th e o n e w h ic h h a v in g m u c h im p a c ts o n a irc ra ft o p e ra tio n s a t JN IA . 1.3 O b jectiv e s; M ain ob jective; T h e o v e ra ll o b je c tiv e is to S tu d y th e im p a c ts o f ra in fa ll o n a ir tr a n s p o rta tio n a t J u liu s N y e re re In te rn a tio n a l A irp o rt. T h e S p e c ific o b je c tiv e s in clud e; a) T o e x a m in e th e te m p o ra l c h a ra c te ris tic o f ra in fa ll at J N IA a n d S h in y a n g a A irp o rt. 11 b) T o id e n tify c a s e s o f d e la y s , c a n c e lla tio n s , d iv e rs io n s o f flig h ts d u e to h e a v y c) rain fa ll. T o stu d y th e w e t sp e lls d u rin g a w e t s e a s o n (In tra S e a so n a l O s c illa tio n s -IS O ) 1.4 S co p e o f th e stu d y; T h e s tu d y w ill c o n c e n tra te m a in ly o n th e la n d in g an d ta k e o f f s ta g e s o f an a irc ra ft at J N IA a s th e s e a re th e p h a se s o f flig h t fo r w h ic h d a ta is a v a ila b le . 1.5 S ig n ific a n c e o f stu d y; T h e s tu d y w ill h e lp in im p ro v in g th e sa fe ty a n d p ro fita b ility o f th e a ir tra n s p o rta tio n c o m p a n ie s , p e o p le w h o a re u sin g a irw a y s fo r th e ir s a fa ris a n d g o v e rn m e n t. A lso th e s tu d y w ill h e lp in re d u c in g a c c id e n ts , u n d e rs ta n d in g lo ca l c lim a to lo g y a n d w ill p ro v id e in fo rm a tio n fo r fu tu re p la n n in g . 1 .6 L it e r a t u r e r e v ie w D u rin g la n d in g o f a irc ra ft th e m ic ro w a v e la n d in g sy s te m is v e ry im p o rta n t in o rd e r to a v o id a n a c c id e n t/ c ra sh in g , T h e M ic ro w a v e L a n d in g S y s te m (M L S ) is in th e p ro c e s s o f b e in g im p le m e n te d w o rld w id e a s th e n e w a ll w e a th e r la n d in g sy s te m fo r a irc ra ft. It w ill re p la c e th e e x is tin g In stru m e n t L a n d in g S y s te m (IL S ). O n e o f th e o p e ra tio n a l re q u ire m e n ts fo r th e sy s te m is to g u id e a irc ra ft to ru n w a y to u c h d o w n in all w e a th e r c o n d itio n s (te rm e d C a te g o ry III). T e s tin g c o n d u c te d in re c e n t y e a rs h a s d e m o n s tra te d th e s e n s itiv ity o f th e p e rfo rm a n c e o f th e m ic ro w a v e a n te n n a s to th e p re s e n c e o f w a te r o n th e a n te n n a ra d o m e . T h e e ffe c ts c a n in c lu d e n o t o n ly d e g ra d a tio n o f th e ra d ia te d sig n a l b u t a ls o d e g ra d a tio n o f s y s te m m o n ito rin g . R e se a rc h h a s b e e n c o n d u c te d to fin d a ra d o m e m a te ria l w ith h y d ro p h o b ic (w a te r sh e d d in g ) p ro p e rtie s s u ffic ie n t to p re v e n t th e a c c u m u la tio n o f w a te r o n th e ra d o m e s a n d th e re b y e lim in a te its e ffe c ts. T h e ra d o m e m a te ria l a lso n e e d s to h a v e a s u ffic ie n t life tim e th a t it d o e s n o t c re a te m a in te n a n c e p ro b lem . T e s tin g c o n d u c te d in re c e n t y e a rs h a s d e m o n s tra te th a t, d u rin g rain fa ll th e s e n s itiv ity o f th e p e rfo rm a n c e o f th e m ic ro w a v e a n te n n a s a re v e ry p o o r d u e to p re s e n t o f w a te r o n a n te n n a ra d o m e , b e c a u se w a te r o n a n te n n a ra d o m e o f a irc ra ft c a u s e s lo s s o f a c c u ra c y , e ffe c tiv e ra d ia te d p o w e r an d s y s te m m o n ito rin g . ( C a sse ll R . 1990). R a in fa ll p re s e n ts m a jo r p ro b le m s o n flig h t p la n s in d iffe re n t a re a s a ro u n d th e w o rld , ra in is th e m o s t w e a th e r c a s e s re p o rte d in m a n y c o u n trie s in w h ic h c a u s e s in te rru p tio n s o f flig h ts e s p e c ia lly w h e n it is a s s o c ia te d w ith p o o r v is ib ility In s u c h p o o r v is ib ility o p e ra tio n m u st b e s to p p e d b y IC A O re c o m m e n d a tio n s , th e re fo re no a irc ra ft a llo w e d to la n d o r ta k e o f f u n til im p ro v e m e n t a c h iev e d . B u rg a u e r D. (2 0 0 0 ). A irlin e flig h t s c h e d u le s a n d d e la y s fo r o n e s p e c ific ro u te fro m L o s A n g e le s to S an F ra n c is c o d u rin g th e m o n th o f S e p te m b e r, H e fo u n d th a t a irlin e s d o te n d to p a d th e ir sc h e d u le d to g iv e th e a p p e a ra n c e th a t flig h ts a rriv e o n tim e m o re fre q u e n tly 12 th a n th e y a c tu a lly do. D e lay s h a v e th u s b e c o m e a sta n d a rd e le m e n t o f a ir tra v e l l^e s a m p le u se d in th e ir re p o rt h a s a m e a n d e la y o f a lm o s t six te e n m in u te s. H o w e v e r i^e m e d ia n d e la y , c o u n tin g e a rly a rriv a ls as n e g a tiv e n u m b e rs , is z e ro m in u te s. S o, ju s t j/w c o m m o n a re d e la y s ? It is c o m m o n to h e a r th e p ilo t a n n o u n c e to th e p a ss e n g e rs th a t e«en th o u g h th e p la n e w a s d e la y e d in ta k in g o f f an d p o s s ib ly le a v in g th e g a te , th e lost tjine w ill b e m a d e u p in th e a ir fo r a n e a rly a rriv a l. S u re ly , th e re is a lim it to th e a m o u n| 0 ^ tim e th a t c a n b e m a d e u p in -flig h t a s e a c h p la n e flie s at a sp e c ific c ru is in g sp e e d . W e a th e r h a s b e e n a ttrib u te d to b e a m a jo r fa c to r in m o st fa ta l a c c id e n ts : o v e r 8 0 y ,°f C o n tro lle d F lig h t in to T e rra in (C F IT ) a c c id e n ts h a p p e n e d w h e n th e p ilo t e ith e r co n tjn)|ec* fly in g in to a d v e rse w e a th e r o r did n o t a p p re c ia te th e e ffe c ts o f th e w e a th e r conditj'ns (T h e S a fe ty L in k , V o l.l N o 5, N o v /D e c 2 0 0 1 ). M S G s a te llite v ie w w ith R G B c o lo r c o m b in a tio n s is th e m o st u se fu l n o w -c a stin g ^ fo re c a s tin g to o l fo r th e o p e ra tio n a l a n d re s e a rc h fo re c a s te rs. W ith R G B c/ o r c o m b in a tio n s it b e c o m e s m u c h e a s ie r to d e te c t se v e re th u n d e rs to rm s , m ic ro b u rst, g f^ 1^ w a v e s , R a in a n d m o u n ta in w a v e s , fo g a t n ig h t a n d e a rly h o u rs o f th e m o rn in g w hicl\ / as d iffic u lt to d e te c t u sin g M e te o s a t 7. T h e s u m m e r o f 2 0 0 5 h a s b e e n n a m e d th e ‘B la c k S u m m e r’ fo r a v ia tio n ; th is f o l l o w ^ c^ e se v e ra l d e a d ly a ir c ra sh e s fo r d iffe re n t a irlin e s in w h ic h c lo se to 5 0 0 p e o p le w e re fro m J u ly 2 0 0 5 . (N e w s 2 4 .c o m , 05 S e p te m b e r 2 0 0 5 ). In s e v e re th u n d e rs to rm s w ith ra in (+ T S R A ) m a n y a c c id e n ts o c c u rre d d u e to ^ v isib ility , d e s tru c tio n o f e le c tric e q u ip m e n ts o n a irc ra ft and w e t ru n w a y . T h e re fo r^ f 1S m o re risk to ta k e flig h t d u rin g + T S R A b e c a u s e w h e n c ru sh in g o c c u rs th e follow ing f re e x p e c te d ; L o s s o f liv e s, D a m a g e t o a irc ra ft an d o th e r p ro p e rtie s , L o s s o f in c o m e to %l,n e c o m p a n ie s as w e ll a s G o v e rn m e n t th ro u g h tax. A m o n g th e m o st h a z a rd o u s w e a th e r fo r a v ia tio n is + T S R A . W e a th e r is re g a rd e d a m ^ p 1 o th e rs a s o n e o f th e m a in c a u s e o f a irc ra ft a c c id e n ts a n d in c id e n ts. D iffe re n t w^ar er h a z a rd s su c h a s T h u n d e rs to rm s , M ic ro b u rs t fro m T h u n d e rsto rm s , M o u n ta in tyave tu rb u le n c e , C le a r a ir tu rb u le n c e (C A T ), W in d s h e a r, P o o r v is ib ility a n d F o g , e tc ^ave b e e n th e c a u se fo r n u m e ro u s a irc ra fts a c c id e n ts a n d in c id e n ts. In s o m e in s ty ces p a s s e n g e rs w e re in ju re d , s o m e e v e n lo st th e ir liv e s a n d so m e a irc ra fts s u ffe re d s t n i ( / r ^ raft d a m a g e s . C A T h a s b e e n th e c a u s e o f n u m e ro u s in c id e n ts w h e re c o m m e rc ia l ai^ p a s s e n g e rs h a v e b e e n in ju re d a n d so m e tim e s d ied (D e V illie rs 1 9 98). A irc ra fts a c c id e n ts a ls o im p a c t fin a n c ia l o n th e a v ia tio n in d u stry . In its fin an c ia l / ear 2 0 0 4 /2 0 0 5 , th e S o u th A fric a n C iv il A v ia tio n A u th o rity (S A C A A ) sp e n t R 6 m i l l i ^ on a c c id e n ts a n d in c id e n ts In v e s tig a tio n s (R u d z a n a M a la la , 2 0 0 5 ) 13 In h is a n n u a l u p d a te o n a ir s h o w a c c id e n ts w o rld w id e , D e s B a rk e r (2 0 0 6 ) h a s e sta b lis h e d th a t th e y e a r 2 0 0 5 w a s th e w o rs t fo r m o re th a n a d e c a d e a n d th a t th e a c c id e n t ra te w o rld w id e h a s sh o w n a d e fin ite in c re a s in g tre n d d u rin g th e p a st fiv e y e a rs (W o rld A ir n e w s, F e b ru a ry 2 0 0 6 , b y D e s B a rk e r). O p e ra tio n a lly to d a y fo r m a n n e d a n d u n m a n n e d a irc ra ft flig h ts, m iss io n p la n n in g a n d flig h t ro u te w e a th e r in fo rm a tio n in th e U S. A rm y an d a c ro s s m u c h o f th e D e p a rtm e n t o f D e fe n s e (D o D ) a re c o n v e y e d to th e p la n n e rs a n d p ilo ts v ia a s ta n d a rd p ilo t w e a th e r b rie fin g fo rm . T h is fo rm p re s e n ts in fo rm a tio n p rim a rily in te x t fo rm a t o r w ith s im p le m ap sk e tc h e s c o v e rin g b ro a d fly in g re g io n s a n d a c ro s s e x te n d e d tim e fra m e s . It is le ft to th e m iss io n p la n n e rs a n d p ilo ts to in fe r th e s p e c ific m e te o ro lo g ic a l c o n d itio n s a lo n g th e in te n d e d ro u te at th e tim e th e a irc ra ft a rriv e s at p a rtic u la r ro u te w a y p o in ts a n d e n ro u te sto p s, a n d th e im p a c t o f th o s e c o n d itio n s o n th e m issio n . T h e d e g re e o f a c c e p ta b le risk c a n b e u se r-d e fin e d a n d d e te rm in e s th e re la tiv e w e ig h t a ss ig n e d to w e a th e r im p a c ts as o p p o s e d to flig h t tim e . S o a “ c a re fu l” p a th w ill ta k e m o re tim e to a v o id w e a th e r im p a c ts, w h ile a m o re “ risk y ” p a th w ill a tte m p t to sa v e tim e b y c u ttin g th ro u g h sm a ll p a tc h e s o f h a rs h e r w e a th e r. D is ta n c e tra v e le d is a c o s t th a t te n d s to d e c re a s e th e len g th o f th e re s u ltin g o p tim iz e d p a th . O r e a c h a irc ra ft b a s e d on th e a irc ra ft’s s p e c ific w e a th e r s e n s itiv ity th r e s h o ld s (K n a p p , 2 0 0 6 ). T h e fin a n c ia l im p lic a tio n o f th e w e a th e r o n a irc ra fts a c c id e n ts is a p e rs is tin g p ro b le m e v e n in fu lly d e v e lo p e d c o u n trie s . W e a th e r is a fa c to r in ro u g h ly 2 3 % o f all a v ia tio n a c c id e n ts a n d a n n u a lly c o s ts th e U S an e s tim a te d $3 b illio n fo r a c c id e n t d a m a g e a n d in ju rie s , d e la y s, a n d u n e x p e c te d o p e ra tin g c o s ts (O ffic e o f th e F e d e ra l C o o r d in a to r fo r M e te o ro lo g y , 1999). 14 CH A PTER TW O 2 .0 D ata and M e th o d o lo g y 2.1 D ata, D ata so u r c e and d a ta q u a lity co n tro l 2.1.1 D ata T h is re s e a rc h u tiliz e s fo c u s o n th e th re e m o n th s p e rio d fro m M a rc h to M a y , w h ic h a re ra in y p e rio d , a n d it c o v e rs p e rio d o f 1 9 9 6 -2 0 0 5 . T w o d a ta set a re u se d in th e stu d y ; R a in fa ll d a ta a n d c h a rts o f e a c h d a y fo r th re e m o n th s , M a rc h , A p ril, a n d M a y fro m lg96 to 2 0 0 5 . T h e s e d a ta a n d c h a rts w e re u se d to s h o w a n d in d ic a te th e tim e a t w h ic h ra in wa s fa llin g in th e sta tio n . D ata o f rain fall (a ) D a ily ra in fa ll d a ta (m m ) fo r th e M A M ra in s e a s o n fo r th e fiv e m o n th s (F e b ru a ry J u n e ) o n b o th s ta tio n s J u liu s N y e re re In te rn a tio n a l A irp o rt and S h in y a n g a A irp o rt fpr th e p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ). (b ) M o n th ly m e a n ra in fa ll fo r th e M A M ra in s e a s o n fo r th e fiv e m o n th s ( F e b r u a r y - J u ^ ) o n b o th s ta tio n s J u liu s N y e r e re In te rn a tio n a l A irp o rt an d S h in y a n g a A irp o rt fo r th^ p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ). (c ) T h e re a re 1 l( H T S Y ) a n d 2 7 (J N IA ) ra in d a y s (h a rd d a y s > /= 50 m m ), n o h e a v y ra jn d a y s (h a rd e r ra in d a y > /= 100 m m ) re p o rte d a n d a lso n o E x tre m e ra in d a y s (h a rd e st ra in d a y s > = 2 0 0 m m ) w a s re p o rte d fo r th e w h o le p e rio d o f te n y e a rs o f s tu d y (19fy)2 0 0 5 ). F lig h t a c c id e n t re p o rts a re o b ta in e d th ro u g h a c c id e n ts re p o rt file s in o p e ra tio n ofifice o f P re c is io n A ir; a ls o re p o rts o f d e la y , c a n c e lla tio n a re o b ta in e d in c o m p ile d file s o f m ayfly o f e a c h d a y in o p e ra tio n o ffic e s o f P re c is io n A ir. D ata o f a irc ra ft o p e ra tio n s (a ) C a n c e lla tio n s o f flig h ts d u e to h e a v y ra in s h a v e b e in g re p o rte d in S h in y a n g a A irp o rt, 157 c a s e s w e re re p o rte d (M a rc h -9 8 , a n d A p ril -5 6 M a y - 3 ) a n d n o c^se w a s re p o rte d a t J u liu s N y e re re In te rn a tio n a l A irp o rt. B e c a u se d u rin g th a t p a rtic u la r tim e th e a e ro d ro m e w a s c lo s e d d u e to flo o d s an d d a m a g e d o f its ru n w a y . ' ‘ 15 (b ) D e la y s o f flig h ts d u e to h e a v y ra in s h a v e re p o rte d o n b o th a e ro d ro m e s , a t Ju liu s N y e re re In te rn a tio n a l A irp o rt 9 c a se s w e re re p o rte d (A p ril-8 a n d M a y -1 ) w h ile i<t S h in y a n g a A irp o rt 8 c a s e s w e re re p o rte d (M a rc h -6 , a n d A p ril-2 ). (c ) N o D iv e rs io n s o f flig h ts d u e to h e a v y ra in s re p o rte d at S h in y a n g a A irp o rt a n d at J u liu s N y e re re In te rn a tio n a l A irp o rt fo r th e w h o le p e rio d o f te n y e a rs (1 9 9 6 2 0 0 5 ). (d ) C a n c e lla tio n s o f flig h ts d u e to h e av y ra in s h a v e b e in g re p o rte d in S h in y a n g a A irp o rt, 157 c a se s w e re re p o rte d (M a rch -9 8 , a n d A p ril -5 6 M a y - 3 ) a n d n o case w a s re p o rte d at J u liu s N y e re re In te rn a tio n a l A irp o rt. B e c a u s e d u rin g th a t p a rtic u la r tim e th e a e ro d ro m e w a s clo sed d u e to flo o d s a n d d a m a g e d o f its ru n w a y . (e ) D e la y s o f flig h ts d u e to h e a v y ra in s have re p o rte d o n b o th a e ro d ro m e s , at Julius N y e re re In te rn a tio n a l A irp o rt 9 cases w e re re p o rte d (A p ril-8 a n d M a y -1 ) w hile i n S h in y a n g a A irp o rt 8 c a s e s w e re rep o rted (M a rc h -6 , a n d A p ril-2 ). (f) N o D iv e rs io n s o f flig h ts d u e to heavy ra in s re p o rte d at S h in y a n g a A irp o rt and a# J u liu s N y e re re In te rn a tio n a l A irp o rt for th e w h o le p e rio d o f te n y e a rs (1 9 9 6 2 0 0 5 ). (g ) N o a irc ra ft a c c id e n ts re p o rte d o n both a irp o rts J u liu s N y e re re In te rn a tio n a l A irp o rt a n d S h in y a n g a A irp o rt w hich a re c a u s e d b y h e a v y ra in s fo r th e perio d te n y e a rs (1 9 9 6 -2 0 0 5 ). (h ) S h in y a n g a a irp o rt d o e s n ’t h a v e good fa c ilitie s a n d s y s te m s fo r la n d in g a n d ta k ^ o f f d u rin g n ig h t tim e , it lac k s o m e im p o rtan t fa c ilitie s su c h a s se c o n d p o w e r s u p p ly a n d A p p ro a c h R u n w a y lighter, n o A T S A irsp a c e , n o A T S c o m m u n ic a tiP n s y s te m , n o R a d io N a v ig a tio n A ids. 2 .1 .2 T h e d a ta S o u rce; T h e d a ta o f w e a th e r p a ra m e te r (R a in ) are o b ta in e d fro m T M A o ffic e s at T a n * # n ia M e te o ro lo g ic a l A g e n c y H e a d Q u a rte r, Julius N y e re re In te rn a tio n a l A irp o rt (J> /I A ) p re v io u s ly c a lle d D a r e s sa laa m International A irp o rt (D IA ) a n d S h in y a n g a a irp o rt. P re c is io n A ir is th e p riv a te a irlin e com pany h a s b e e n o p e ra tin g in T a n z a n ia fo r s e / e r a l y e a rs (m o re th a n ten y e a rs). T h is a irlin e com pany ta k e s a b o u t 7 0 % o f flig h ts o p e r a te s in T a n z a n ia e v e ry d a y , th e re fo re its perform ance is h ig h c o m p a re d to a n y o th e r [ ,o c a l c o m p a n ie s su c h a s A ir T a n z a n ia C ooperation (A T C ), T a n z a n A IR , a n d C o m m u n ity e tc . • • 16 ^ ir It is b e tte r to u s e d a ta fro m P re c is io n A ir b e c a u s e ; . It h a s d iffe re n t ty p e s o f a irc ra fts . It tra v e ls a t m o s t ro u te s in T a n z a n ia . It h a s d a ily flig h ts a t m o st ro u te s in T a n z a n ia T h e re fo re th e re q u ire d d a ta o f d e la y s, C a n c e lla tio n s o f flig h ts w e re o b ta in e d a t o p tim u m n u m b e r. 2 .1.3 D ata Q u a lity co n tro l (i) F o r h o m o g e n e ity te s t, a sin g le m a s s c u rv e m e th o d w a s a p p lie d to te s t th e ra in fa ll d a ta , sta rtin g th e m o st c u rre n t g o in g b a c k w a rd s fro m b o th s ta tio n s J u liu s N y e re re In te rn a tio n a l A irp o rt a n d S h in y a n g a A irp o rt a s sh o w n b e lo w ; 1996 7 9 2 .3 1997 1 5 1 5 .3 1998 2309 1999 2000 2 9 9 2 .1 3 6 9 4 .1 2001 4 3 7 7 .6 2002 2003 5 0 0 3 .2 5 6 6 3 .4 2004 6 3 0 7 .3 T a b le 2; J N IA M A M C u m u la tiv e ra in fa ll. DAR(JNIA) MASS CURVE c_> 1 2 3 4 5 6 PERIOD (YEARS) F ig u re 3 ; J N IA m a ss c u rv e . 17 7 8 9 10 2005 6 8 5 1 .2 1996 5 7 4 .8 1997 1 1 2 1 .6 1998 1 5 2 1 .6 1999 1 9 1 9 .6 2000 2279 2001 2 7 6 9 .8 2002 3 3 1 8 .1 2003 3 7 0 9 .4 2004 4 1 1 5 .9 T a b le 3; S h in y a n g a a irp o rt M A M C u m u la tiv e ra in fa ll. F ig u re 4; S h in y a n g a a ir p o r t m a s s cu rv e . (ii) N o m is sin g d a ta o n b o th d a ta sets, th e re fo re n o sta tistic a l m eth o d w a s e m p lo y e d . 2 .2 M e t h o d o lo g y T h e m e th o d s th a t h a v e b e in g e m p lo y e d in th e p re s e n t stu d y include; tim e se rie s a n a ly sis g ra p h ic a l a n a ly s is a n d c o rre la tio n a n a ly sis, 2.2.1 T im e series a n a ly s is T h e tim e s e rie s a n a ly s e s a re u s e d to stu d y th e te m p o ra l p a tte rn o f rainfall. T h e re fo re the se a so n , m o n th ly a n d d a il y ra in fa lls w e re s u b je c te d to tim e s e rie s analysis. 18 2005 4 4 8 9 .9 2 .2 .2 G r a p h ica l m eth od T h e G ra p h ic a l m e th o d w a s u s e d to s tu d y th e re la tio n s h ip b e tw e e n ra in fa ll a n d e v e n ts s u c h as; - R a in fa ll p e rio d (tim e ) v e rs u s a irc ra ft d e la y in g R a in fa ll p e rio d (tim e ) v e rs u s a irc ra ft c a n c e lla tio n 2 .2 .3 C o rre la tio n A n a ly sis It w a s u se d to q u a n tify th e re la tio n s h ip s b e tw e e n lo n g ra in s e a s o n (M a rc h , A p ril a n d M a y -M A M ) a n d a irc ra fts o p e ra tio n s fo r th e w h o le p e rio d o f 10 y e a rs (1 9 9 6 -2 0 0 5 ). I f it w a s ra in day , w h a t h a p p e n e d to a irc ra fts o p e ra tio n s at J N IA a n d S h in y a n g a a irp o rt 19 CHAPTER THREE 3 .0 R E S U L T S A N D D IS C U S S IO N S 3.1 R esu lts fro m T im e ser ie s A n a ly sis; 3 .1.1 S ea so n ra in fa ll (M A M ) A n a ly sis 3 .1 .1 .1 J N IA sea so n rain (M A M ) A n a ly sis 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 5 5 5 .5 5 6 7 .9 6 4 0 .1 6 2 4 .4 4 3 9 .6 5 9 8 .2 7 9 6 .7 2 6 6 .9 4 5 1 .4 5 0 2 .2 T a b le 4; J N IA M A M - to ta l ra in fa ll (m m ). JNIA SEASON (MAM) RAIN GRAPH 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 YEARS F ig u r e 5; J N I A M A M to ta l r a in fa ll g ra p h . 20 5442.9 T h e r e s u lt s f r o m a b o v e J N I A T a b le 4 a n d F ig u r e 5 s h o w th a t; (i) T h e y e a r 2 0 0 2 h a d th e w e tte s t s e a s o n (7 9 6 .7 m m ) a m o n g th e te n y e a rs o f s tu d y (1 9 9 6 -2 0 0 5 ). (ii) T h e y e a r 2 0 0 3 h a d th e d rie s t s e a s o n (2 6 6 .9 m m ) a m o n g th e te n y e a rs o f s tu d y (1 9 9 6 -2 0 0 5 ). 3 .1 .1 .2 H T S Y sea so n rain (M A M ) A n a ly sis 1996 1997 1998 1999 2000 2001 2002 2003 2004 3 5 3 .3 3 8 6 .7 2 7 0 .8 3 4 6 .2 2 6 1 .6 2 8 1 .6 4 4 7 .5 2 7 8 .1 2 6 9 .0 T a b le 5: S h in y a n g a a irp o rt M A M - to ta l ra in fa ll (m m ) 21 2005 3 0 7 .4 T h e r e s u lt s fr o m H T S Y T a b le 5 a n d F ig u r e 6 a b o v e s h o w that; (i) T h e y e a r 2 0 0 2 is th e w e tte s t y e a r ( 4 4 7 .5 m m ) fo r th e period o f t e n y e ^rs ^ j 9 9 ^ 2 0 0 5 ). (ii) V W h ile 2 0 0 0 y e a r in d ic a te d a s th e d rie s t y e a r (2 6 1 .6 mm) o v e r t *ie stu d y . 3 .1 .2 M o n th ly rain fall d a ta A n a ly sis 3 .1.2 .1 J N IA M o n th ly rain fall d a ta A n a ly sis MEAN MONTHLY RAINFALL(MM) MONTH FEBR 8 2 .8 MAR 1 7 3 .6 APR 2 4 8 .9 MAY 121.8 JUN 5 8 .0 T a b le 6; M e a n m o n th ly ra in fa ll fo r J N IA in M A M JNIA MAM RAINFALL DISTRIBUTION F i g u r e 7 ; J N I A m o n t h l y r a i n f a l l d i s t r i b u t i o n in M A M . y e a rs 0 f 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2 3 3 .1 2 8 2 .8 1 5 5 .2 2 2 2 .1 1 6 9 .9 1 3 9 .0 1 9 7 .2 1 2 2 .4 1 3 4 .5 8 0 .2 2 2 3 .2 1 6 7 .7 3 1 9 .9 2 5 8 .9 2 2 2 .1 2 9 6 .7 5 6 9 .4 1 3 .7 2 9 7 .6 1 1 9 .4 9 9 .2 1 1 7 .4 1 6 5 .0 1 4 3 .4 4 7 .6 1 6 2 .5 3 0 .1 1 3 0 .8 1 9 .3 3 0 2 .6 T a b le 7 ; J N I A M a r c h , A p ril a n d M a y r a in f a ll ( m m ) MONTHLY RAIN GRAPH 600.0 500.0 e 400.0 ^300.0 U- 200.0 - on 100.0 0.0 IIII.I.I 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 YEARS F ig u re 8; J N IA M o n th ly (M A M ) ra in fa ll g ra p h . T h e resu lts from J N IA T a b les (6 & 7 ) and F igu res (7 & 8 ) a b o v e sh o w that; (i) T h e m e a n w e tte s t m o n th a t J N IA w a s A p ril (2 4 8 .9 m m ), w h ile th e m e a n d rie st m o n th w a s M a y (1 2 1 .8 m m ) fo r th e p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ). (ii) T h e w e tte s t M a rc h w a s 19 9 7 (2 8 2 .8 m m ), w h ile th e d rie s t M a rc h w a s 2 0 0 5 (8 0 .2 m m ). (iii) T h e w e tte s t A p ril w a s 2 0 0 2 (5 6 9 .4 m m ), w h ile th e d rie s t A pril w a s 2 0 0 3 (1 3 .7 m m ). «- V 23 TOTAL 1736.4 2488.6 1217.9 (iv ) T h e w e tte s t M a y w a s 2 0 0 5 (3 0 2 .6 m m ), w h ile th e d rie s t M a y w a s 2 0 0 4 (1 9 .3 m m ). (v ) T h e h ig h e s t ra in fa ll m o n th w a s A p ril (2 0 0 2 , 5 6 9 .4 m m ), w h ile th e lo w e st rain fa ll m o n th w a s A p ril (2 0 0 3 , 13.7 m m ). 3 .1 .2 .2 H T S Y M o n th ly ra in fa ll d a ta A n a ly sis MEAN MONTHLY MONTH RAINFALL(MM) FEB 127 MAR 179.1 APR 104.4 MAY 36.7 JUN 1.0 T a b le 8; M e a n m o n th ly ra in fa ll fo r H T S Y in M A M HTSY MAM RAINFALL DISTRIBUTION FEB MAR APR MAY MONTHS F ig u re 9: S h in y a q g a a irp o rt m o n th ly ra in fa ll d is trib u tio n in M A M . JUN AR pR ay 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2 6 6 .8 1 3 9 .4 1 1 2 .5 2 8 9 .7 1 8 3 .1 1 7 1 .5 2 2 4 .9 8 0 .0 1 7 5 .7 1 4 7 .5 4 9 .2 1 8 4 .7 1 0 2 .8 5 4 .1 7 8 .5 9 2 .0 1 4 2 .4 1 5 9 .4 9 3 .3 8 7 .8 3 7 .3 6 2 .6 5 5 .5 2 .4 0 .0 18.1 8 0 .2 3 8 .7 0 .0 7 2 .1 TO 1 1 T a b le 9: S h in y a n g a a irp o rt M a rc h , A p ril a n d M a y ra in fa ll (m m ) MAM GRAPH 2 150.0 < 1 0 0 .0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 YEARS F ig u re 10: S h in y a n g a a irp o rt F e b ru a ry , M a rc h , A p ril a n d M a y ra in fa ll g ra p h T h e resu lts from ta b les (8 & 9 ) and F ig u res (9 & 1 0 ) a b o v e sh o w th at; (i) M a rc h w a s th e w e tte s t m o n th at S h in y a n g a A irp o rt (1 7 9 .1 m m ), w h ile M a y w a s th e d rie s t m o n th (3 6 .7 m m ) o v e r th e p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ). (ii) T h e w e tte s t M a rc h w a s 199 9 (2 8 9 .7 m m ), w h ile th e d rie s t M a rc h w a s 2 0 0 3 (8 0 .0 m m ). (iii) T h e w e tte s t A p ril w a s 199 7 (1 8 4 .7 m m ), w h ile th e d rie s t A p ril w a s 199 6 (4 9 .2 m m ). (iv ) (0 .0 m m ). T h e w e tte s t M a y w a s 2 0 0 2 (8 0 .2 m m ), w h ile th e d rie s t M a y w a s 2 0 0 0 a n d 2 0 0 4 25 T h e h ig h e s t ra in fa ll m o n th w a s M a rc h (1 9 9 9 , 2 8 9 .7 m m ), w h ile th e lo w e st (v ) rain fa ll m o n th w a s M a y (2 0 0 0 a n d 2 0 0 4 , 0 .0 m m ). 3 .1 .3 3 .1 .3 .1 D aily ra in fa ll d a ta a n a lysis J N IA O n set a n d C e ssa tio n from P en tad ra in fall d a ta JNIA ONSET AND CESSATION GRAPH ■S eries 1 ^ ^ Or # O # o< r< ^ ^ ^ < ^ <r <r <r <r ^ <?' ^ O* ^ ^ <r<r<r<F PENTAD F ig u re 11; J N IA p e n ta d s g ra p h s h o w th e m e a n o n s e t a n d c e ss a tio n . T h e p e n ta d o f o n s e t /c e s s a tio n is th e tim e w h e n th e re is a su d d e n in c re a s e /d e c re a s e in ra in fa ll v a lu e s (O g a llo , 1994). T h e resu lts from fig u r e 11 a b o v e o f J N IA d u r in g M A M rain sea so n h a v e sh o w ed th at; (i) T h e m e a n o n s e t n o rm a lly s ta rts in th e th ird w e e k o f M a rc h (P e n ta d 11). (ii) A p ril h a v e m u c h ra in s c o m p a re d to M a rc h a n d M a y d u rin g M A M se a so n . (iii) T h e m e a n c e s s a tio n o f M A M ra in se a s o n a t J N IA is in th e fo u rth w e e k o f M a y (P e n ta d 2 5 ). . . 26 A n a ly s is fro m d a ily ra in c h a rts o f J N IA fo r th e p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ) d u rin g M A M ra in s e a s o n s h o w s th a t; (i) B e tw e e n 1 2 .0 0 n o o n an d 0 4 .0 0 p m , it se e m s to b e th e m o s t d o m in a n t tim e fo r ra in s at J N IA e sp e c ia lly d u rin g M a rc h a n d A pril. (ii) B e tw e e n 0 3 .0 0 a m a n d 1 0 .0 0 a m , it is th e tim e at w h ic h m o re ra in s d o m in a te s at th e e n d o f A p ril a n d m id o f M a y . (iii) C h a rts h a v e s h o w e d th a t, th e re a re m u c h d ry sp e lls b e tw e e n 0 9 .0 0 p m a n d 0 2 .0 0 a m . 3 .1 .3 .2 H T S Y O n set a n d C e ssa tio n from P en tad ra in fall d a ta HTSY ONSET AND CESSATION GRAPH 700 600 S s J 500 400 < 300 £ 200 - ♦- S e r i e s l 100 0 PENTAD F ig u re 12; H T S Y p e n ta d s g ra p h s h o w th e m e a n o n se t a n d c e ss a tio n . T h e resu lts from fig u r e 12 a b o v e o f H T S Y d u rin g M A M rain sea so n h a v e sh o w e d that; (a ) T h e m e a n o n s e t n o rm a lly s ta rts at th e th ird w e e k o f M a rc h (P e n ta d 11). (b ) M a rc h h a v e m u c h ra in s c o fh p a re d to A p ril a n d M ay . 27 (c ) M a y is th e m o n th o f lo w a m o u n t o f rain fa ll in M A M ra in se aso n . (d ) T h e m e a n c e s s a tio n is o n se c o n d w e e k o f M a y (P e n ta d 21). A n a ly s is fro m d a ily ra in c h a rts o f H T S Y fo r th e p e rio d o f te n y e a rs (1 9 9 6 -2 0 0 5 ) d u rin g M A M ra in s e a s o n s h o w s th a t; (a ) B e tw e e n 0 6 .0 0 p m an d 1 1 .0 0 p m is th e tim e a t w h ic h m o st ra in re p o rte d (w e t s p e lls ) d u rin g M a rc h a n d A p ril. (b ) B e tw e e n 0 0 .0 0 m id n ig h t an d 0 5 .0 0 a m is th e tim e (a c tiv e tim e ) a t w h ic h m o st ra in s re p o rte d at th e th ird w e e k o f F e b ru a ry a n d se c o n d w e e k o f M ay . (c ) B e tw e e n 0 6 .0 0 am a n d 0 0 .0 0 n o o n is th e m o s t d ry sp e lls p e rio d . 28 3.2 R esu lts from G r a p h ica l m eth o d (h isto g r a m ) A n a lysis; 3.2.1 J N IA A irc ra ft o p e r a tio n s d a ta A n a ly sis S E R IA L NUM BER DATE A M M O U N T O F R A IN F A L L (M M )R A IN D A Y (> 5 0 M M ) 1 M a rc h 18th 1996 78.1 2 M a rc h 2 5 th 1996 6 0 .9 3 ~ M a r c h 2 6 th 1997 6 9 .0 4 M a rc h 2 3 rd 1998 50.1 5 A p ril 2 8 th 1998 67.1 6 M ay 0 2 nd 1998 6 9 .9 7 M ay 0 3 rd 1998 6 9 .5 8 M a rc h 16th 1999 5 6 .2 9 M a rc h 2 5 th 1999 5 4 .4 10 M ay 13th 1999 5 7.3 11 M a rc h 3 1st 2 0 0 0 6 1 .6 12 M a rc h 2 6 th 2001 6 5 .3 13 A p ril 0 2 nd 2001 58.1 14 A p ril 2 0 th 2001 5 9.3 15 M ay 2 0 th 2001 6 2 .5 16 M a rc h 10th 2 0 0 2 5 0 .8 17 A p ril 0 1 st 2 0 0 2 7 5 .9 18 A p ril 0 4 th 2 0 0 2 5 0 .6 19 A p ril 11th 2 0 0 2 6 4 .4 20 A p ril 0 3 rd 2 0 0 4 5 6 .2 21 A p ril 0 4 th 2 0 0 4 66.1 22 A p ril 12th 2 0 0 4 6 4 .0 23 M ay 2 0 th 2 0 0 5 9 5 .7 T a b le 10; S h o w th e n u m b e r a n d d a te o f ra in d a y s a t J N IA , th e re d n u m b e r o n th e table in d ic a te a ls o th e d a y s o f d e la y s. N ote; It re p o rte d a s ra in d a y (h a rd d a y ) i f th e to ta l a m o u n t o f ra in fa ll m e a su re d within 2 4 h o u rs b e g in n in g a t 0 9 .0 0 am (0 6 0 0 G M T ) o f th e first d a y u p to th e sa m e tim e in the n e x t > d a y is e q u a l o r e x c e e d 5 0 m m , a n d h e a v y ra in d a y (h a rd e r d a y ) re p o rte d i f it is greater o r e q u a l to 100 m m , w h ile E x tre m e ra in d a y (h a rd e s t d a y ) re p o rte d i f it is g re a te r o r equal to 2 0 0 m m . (L u H a n C h e n g an d Y a n g X in v ie r, 1996). 29 T h e r e f o r e n o h e a v y ra in d a y s o r e x tre m e ra in d a y s w e re re p o rte d at J N IA in all te n y e a rs o f t h i s s tu d y DAYS (DATE) F i g u r e 13; S h o w th e ra in d a y s a t JN IA S E R IA L DATE N O . O F D E L A Y (>1 H O U R ) NUM BER 1 M a rc h 18th 1996 1 2 M a rc h 2 6 th 1997 1 1 3 4 M ay 0 2 nd 1998 1 5 A p ril 0 2 nd 2 0 0 f 1 6 M ay 2 0 fll 2001 1 7 A p ril 0 1 st 2 0 0 2 1 8 A p r iT W ^ M y T 1 9 A p ril 1 10 M a y ~20n n 2 0 0 5 ~ 12th 2 0 0 4 T a b l e 11; S h o w th e n u m b e r a n d d a te o f D e lay s a t .1NIA 30 if 1 JNIA DELAYS GRAPH YEARS F ig u re 14; S h o w th e n u m b e r o f flig h ts d e la y e d at J N IA . N ote; D e la y (s) o f flig h t re p o rte d i f a n a irc ra ft fa ile d to ta k e o f f fo r so m e h o u rs (>1 h o u r) fro m its re q u ire d tim e (D e p a rtu re T im e ), th e o p e ra tio n s h a v e s to p p e d fo r s o m e tim e u n til th e im p ro v e m e n t o f w e a th e r p a ra m e te rs (e g. v e rtic a l a n d h o riz o n ta l v is ib ility ) w ith in a n d a ro u n d th a t p a rtic u la r a e ro d ro m e . F rom J u liu s N y e re re In ter n a tio n a l a irp o rt h isto g r a m s a b o v e (F ig .1 3 & sh o w e d th a t; (a ) 14), it M o s t d e la y s o c c u rre d in A p ril (5 ), it fo llo w e d b y M a y (3 ) a n d th e n M a rc h (2 ) fo r th e te n y e a rs (1 9 9 6 -2 0 0 5 ) o f th is stu d y . (b ) N o flig h t d e la y w a s re p o rte d in 1999, 2 0 0 0 an d 2 0 0 3 , b u t h ig h e s t n u m b e rs o f d e la y s (2 ) w e re re p o rte d in 1998, 200 1 an d 2 0 0 2 . (c ) A p ril 2 0 0 2 w a s o n ly m o n th at w h ic h h ig h e s t (2 ) d e la y s w e re re p o rte d in th is stu d y . T h e resu lt fro m th e tab les (1 0 & 1 1 ), it sh o w s that; A t J N IA th e re a re c o rre la tio n s b e tw e e n d a y s o f d e la y s a n d ra in d a y s, sin c e th e re a re 23 ra in d a y s a n d 10 flig h ts d e la y s w h e re b y th o s e 10 d a y s o f d e la y s o c c u rre d w ith in th o s e 23 ra in d a y s. 31 3 .2 .2 H T S Y A ir c r a f t o p e r a t io n s d a t a A n a ly s is S E R IA L NUM BER A M M O U N T O F R A IN F A L L (M M )- DATE R A IN D A Y (> 5 0 M M ) 1 M a rc h 2 9 th 1997 8 1 .4 2 M a rc h 9 th 1998 5 4 .0 3 A p ril 2 nd 6 2 .6 4 M a rc h 14th 1 9 9 < T 6 2 .4 5 A p ril 2 nd 2 0 0 3 9 3 .6 6 M a rc h 9 th 2 0 0 4 6 0 .0 7 M a rc h 11th 2 0 0 4 5 4 .6 8 A p ril 0 8 th 2 0 0 5 5 6 .8 1998 T a b le 12; S h o w th e n u m b e r a n d d a te s o f ra in d a y s at H T S Y , w h e re re d c o lo r n u m b e rs a re a ls o a p p e a rs o n th e ta b le o f H T S Y d e la y s. F ig u re 15; S h o w th e ra in d a y s at H T S Y . S E R IA L NUM BER DATE N O . O F D E L A Y (>1 H O U R ) 1 M a rc h 2 9 th 1997 1 2 M a rc h 9 th 1998 1 3 M a rc h 14th 1999 1 4 A p ril 2 nd 2 0 0 3 1 5 M a rc h 9th 2004 1 6 M a rc h 11th 2004 1 7 A p ril 0 8 th 2 0 0 5 1 T a b le 13; S h o w th e n u m b e r a n d d a te s o f d e la y s a t H T S Y HTSY DELAYS GRAPH YEARS F ig u re 14; S h o w th e n u m b e r o f flig h ts d e la y e d at H T S Y . 33 T a b le 14; S h o w th e n u m b e r a n d d a te s o f C a n c e lla tio n s a t H T S Y S E R IA L NUM BER 1 DATE M a rc h 2 7 th & 2 9 th NO. OF C A N C E L L A T IO N 3 1996 2 A p ril 0 4 th 1996 1 3 M a r c h l5 ,1 7 ,2 9 & 3 1 1997 4 4 A p ril 0 3 rd 1997 1 5 M a rc h 7 ,1 0 & 2 8 3 1998 6 A p ril 05 1998 1 7 M a rc h 0 6 ,1 3 ,1 5 & 2 6 4 1999 8 A p ril 0 2 nd 1999 1 9 M a rc h 12th 2 0 0 0 1 10 M a rc h 0 6 & 1 1 2001 2 11 A p ril 0 9 th 2001 1 12 M a rc h 5 ,1 2 ,2 4 & 2 8 th 4 2002 13 A p ril 2 1 & 3 0 th 2 0 0 2 2 14 M a rc h 2 4 ,2 6 & 3 1 st 2003 3 15 A p ril 2 2 nd 2 0 0 3 1 16 M a rc h 1 0 ,1 2 & 1 4 th 3 2004 17 A p ril 0 5 th 2 0 0 4 1 18 M a rc h 0 7 & 2 0 th 2005 2 19 A p ril 0 9 th 2 0 0 5 1 20 M a y 0 2 nd 2 0 0 5 1 39 TOTAL 34 HTSYCANCELLATIONS GRAPH ■CANCELLATIONS MARCH ■CANCELLATIONS APRIL □ CANCELLATIONS MAY c \V & r^> N° YEARS F ig u re 15; S h o w th e n u m b e r o f flig h ts C a n c e lle d a t H T S Y . N ote; C a n c e lla tio n (s ) o f flig h t re p o rte d i f a n a irc ra ft fa ile d to ta k e o f f fro m o n e a irp o rt to a n o th e r.(E .g . fro m J N IA to H T S Y ). T h e m o st o p e ra tio n s o f a irc ra fts in m a n y a e ro d ro m e s in T a n z a n ia a re a ffe c te d b y ra in (ra in d a y s) e s p e c ia lly fo r th o s e a e ro d ro m e s w h ic h h a v in g a n u n p a v e d ru n w a y . F rom S h in y a n g a a ir p o rt h isto g r a m s a b o v e (F ig . 1 4 & 1 5 ), it sh o w e d that; (a ) M o st c a n c e lla tio n s o c c u rre d o n M a rc h (2 8 ), it fo llo w e d b y A p ril (1 0 ) a n d th e n M a y ( 1). (b ) M o s t d e la y s o c c u rre d in M a rc h (6 ), it fo llo w e d b y A p ril (1 ) a n d n o d e la y e d w a s re p o rte d in M a y . t © T h e h ig h e s t n u m b e r o f d e la y s ,w $s re p o rte d in M a y 2 0 0 5 (2 ), b u t n o d e la y e d w a s re p o rte d in 1 9 9 6 , 1998, 2 0 0 0 , 2001 an d 2 0 0 3 . 35 T h e resu lt fro m th e ta b les 1 2& 13 a n d F ig u re 14 a b o v e , it sh o w s th at; A lso a t H T S Y th e re a re c o rre la tio n s b e tw e e n d a y s o f d e la y s a n d ra in d a y s, sin c e th e re a re 8 ra in d a y s a n d 7 flig h ts d e la y s w h e re b y th o s e 7 d a y s o f d e la y s o c c u rre d w ith in th o s e 8 ra in d a y s. T h e resu lt fro m th e tab les 1 2 & 1 4 an d F igu re 15 a b o v e, it sh o w s th a t; A t H T S Y th e re a re a lso so m e c o rre la tio n s b e tw e e n d a y s o f c a n c e lla tio n s an d ra in d a y s, sin c e th e re a re 8 ra in d a y s a n d 3 9 flig h ts c a n c e lla tio n s w h e re b y th o s e 3 9 d a y s o f c a n c e lla tio n s o c c u rre d w ith in a n d a fte r th o s e 8 ra in d a y s 36 C H A PTER FOUR 4 .0 C O N C L U S IO N S A N D R E C O M M E N D A T IO N S 4.1 C O N C L U S IO N S (i) H e a v y ra in s c a u se s o m e c a n c e lla tio n s o f flig h ts p a rtic u la rly a t S h in y a n g a air Po rt (ii) T h e a e ro d ro m e a t S h in y a n g a a irp o rt w a s c lo s e d d u e to A v ia tio n S a fe ty R e g u la tio n s w h ic h d o e s n o t a llo w th e ta k e o f f a n d la n d in g o f a irc ra fts in th e flo o d s ru n w a y s (iii) D e la y s o b s e rv e d in b o th a irp o rts , J u liu s N y e r e re In te rn a tio n a l A irp o rt and S h in y a n g a A irp o rt. (iv ) A p ril is th e w e tte s t m o n th at J u liu s N y e re re In te rn a tio n a l A irp o rt, w h ile I n a r c h is th e w e tte s t m o n th at S h in y a n g a A irp o rt. (v ) O n s e t o f M A M ra in s e a s o n a t S h in y a n g a a irp o rt a n d J u liu s N y e re re In te rn a t ‘o n a ' A irp o rt a re o n th ird w e e k o f M a rc h . (v i) C e s sa tio n o f M A M ra in s e a s o n is o n se c o n d w e e k o f M a y a t S h in y a n g a a ‘r Po rt a t J u liu s N y e re re In te rn a tio n a l A irp o rt is o n fo u rth w e e k o f M ay . 4 .2 R E C O M M E N D A T IO N S (i) S h in y a n g a a irp o rt sh o u ld b e C o n s tru c te d to b e e it h e r C a te g o ry A o r B in <?r d e r r e m o v e th e p ro b le m o f c a n c e lla tio n s o f flig h ts w h ic h h a v e c a u s e d b y rain s. (ii) F lig h ts p la n n in g s h o u ld u s e d a ily w e a th e r f o r e c a s ts a n d T e rm in a l A e r o d to m e s F o re c a s ts (T A F ) in o rd e r to m in im iz e th e p ro b le m s o f flig h t d e la y s in d iffe rtfn t a e ro d ro m e s. (iii) T h e su g g e s tio n fo r fu rth e r stu d y ; It is im p o rta n t t o k n o w w h y a t S h in y a n § a t ^ie m e a n o n s e t is o n th ird w e e k o f M a rc h a n d d a ta sa y s t h e h ig h e s t ra in fa ll m o n 1*1 *s M a r c h as w ell. 37 ACKNOW LEDGEM ENTS; I w is h to e x te n d m y s in c e re th a n k s / g ra titu d e ’s to m y S u p e rv is o rs D r R E . O k o o la a n d D r J.N . In in d a fo r th e ir c o u n se l a n d a d v ic e in th e p ro s p e c tiv e d e v e lo p m e n t, fu rth e ra n c e and fin a l p re s e n ta tio n o f th is p ro je c t p a p e r, a n d all D e p a rtm e n t s ta f f a n d L e c tu re rs w h o s e id e a s/c o m m e n ts w e re in c o rp o ra te d in m a k in g th is w o rth w h ile p a p er. M a n y th a n k s g o to T a n z a n ia M e t A g e n c y s ta f f fo r th e ir a s sis ta n c e in th e d a ta a c q u isitio n , R e fe re n c e m a te ria ls a n d a d v ic e . A lso m a n y th a n k s g o to P re c is io n A ir s ta f f fo r th e ir im m e a su ra b le c o o p e ra tio n an d a s sis ta n c e in g e ttin g th e n e c e ss a ry d a ta fo r m y re s e a rc h w o rk s e s p e c ia lly M r. P e te r M w e n iso n g o le (T h e o p e ra tio n m a n a g e r- P re c is io n A ir T a n z a n ia). S p e c ia l th a n k s g o to all o f m y frie n d s a n d a s so c ia te s w h o m a d e th e life e a sie r, e n jo y a b le a n d w o rth liv in g th ro u g h o u t m y stu d y . T h a n k s G O D fo r k e e p in g m e in g o o d h e a lth a n d o f so u n d m in d th ro u g h o u t m y stu d y , i b e lie v e w ith o u t y o u n o th in g c a n b e d o n e , c o n tin u e to s h o w m e th e w a y s w h e re th e re s e e m e d to b e n o w a y , a n d c o n tin u e k e e p in g m e in th y lig h t. A M E N . 38 V R e fe r e n c e s A u stra lia n G o v e rn m e n t B u re a u o f M e te o ro lo g y (2 0 0 6 ); E ffe c ts o f th u n d e rs to rm s o n a irc ra fts , p rin te d a n d p u b lis h e d b y C o m m o n w e a lth o f A u stra lia . B u rg a u e r D . (2 0 0 0 ). A irlin e flig h t s c h e d u le s a n d d e la y s d u e to b a d w e a th e r in S a n F ra n s is c o - A m e ric a . C a sse l R .(1 9 9 0 ) ;T h e e ffe c ts o f ra in o n m ic ro w a v e L a n d in g S y s tem a n te n n a _ ra d o m e s , W in n ip e g P u b lis h in g C O . M o n tre a l, C a n a d a . D e V illie rs (1 9 9 8 ). C le a r a ir tu rb u le n c e (C A T ) h a s b e e n th e c a u s e fo r n u m e ro u s a irc ra fts a c c id e n ts a n d in c id e n ts. D o u g la s D C (2 0 0 2 ) U n c o n tro lle d flig h t 8 0 8 o f A m e ric a n I in te rn a tio n a l A irw a y s C o llis io n w ith te rra in . E a s t A frica M e te o ro lo g ic a l D e p a rtm e n t (1 9 7 5 ) c lim a to lo g ic a lly s ta tis tic s fo r E a s t A fric a F u jita T .T (1 9 8 1 ); M ic ro b u rs t a s an a v ia tio n w in d s h e a r h aza rd s,_ A IA A 19th A e ro s p a c e sc ie n c e m e e tin g , st L o u is M iss o u ri U S A. K n a p p D ., T e rry J a m e s o n T ., M e a s u re E. ( 2 0 0 7 ) ; O p tim iz e d flig h t ro u tin g b a s e d o n w e a th e r im p a c ts g rid s , P rin te d b y p h y s ic a l sc ie n c e la b o ra to ry , L a s c ru c e s , N e w M e x ic o . L e is te r P .F (2 0 0 0 ); A v ia tio n w e a th e r, 2 nd E d itio n , J e p p e s e n S a n d e rs o n In c, 2 0 0 0 (IS B N 0 -8 8 4 8 7 -2 7 3 -4 ). M a la la R. (2 0 0 5 ) Im p a c t o f w e a th e r o n a irc ra fts a c c id e n ts , S o u th A fric a n W e a th e r S e rv ic e s. O k o o la R E a n d A m b e n je P .G . (2 0 0 3 ) t r a n s i t i o n fro m th e so u th e rn to th e N o rth e rn H e m is p h e re s u m m e r o f z o n e o f a c tiv e c o n v e c tio n o v e r C o n g o B a sin , P rin te d in A u stria , M e te o ro lo g y a n d A tm o s p h e ric p h y s ic s 8 4 ,2 5 5 -2 6 5 . T a n g W e n g C ., S h u n H o C ., a n d L in G u a n W . (2 0 0 2 ); A s tu d y o n w in d .s h e a r id e n tific a tio n ,^ N a tio n a l C h e n g K u n g U n iv e rs ity N o 1, U n iv e rs ity R o a d , T a in a n 7 0101 T a iw a n R O C . T a n z a n ia C iv il A v ia tio n A u th o rity (T C A A ) A e ro n a u tic a l In fo rm a tio n C irc u la r (2 0 0 0 ); th e e ffe c ts o f th u n d e rs to rm s a n d a s so c ia te d tu rb u le n c e o n a irc ra ft o p e ra tio n s . T h e S a fe ty L in k , V o l.l N o 5, (N o v /D e c 2 0 0 1 ). T h e e ffe c ts o f th e w e a th e r c o n d itio n s o n flig h t o p e ra tio n s . 39 -