submission - Independent Pilots Association

*
'1989 ) a¡-;ues that. up to 2.1 hours *'ithout slccp. cr¡cad¡a¡ rnfluenccs probabl¡ have greater
circcts th¡¡ trmc since a*'ale.
ln Japan. tl { percen¡ of d¡o*sincss-rclared nea¡accidens rn elccrnc motor locomotire dnrcrs
r Kogi & Obt¡. 1975) occut at night. Orhcr la¡rdrna¡t srudics ovcr tbe past scveral dccadcs
bave documntcd the increasc in accidcns a¡¡d crror making. Kleia er d. (1970) argue rhar thci¡
resca¡ch uitlr simulalors Prov6 that night flighs ¡rE a g¡cåtcr risk tha¡ day flighs. Thcir resca¡ch
fq¡nd 75- to 100-pcrcent rEåtì pcrforrneacc efficþæy dccrcnrcnrs i¡ simula¡or fligbrs dnring thc
cerly nrorning bours, rcierdbss of e¡tc¡¡d fæta sæh as da¡lcncss or i¡cæasing nigbt uafñc-or
poesible sc¿tbcr conditioos.
Task pcrfonnancc in e vuicty of nigbtllùc hes bæo comparcd wi¡h perform¡ace of their d¡niræ
co.¡ntcrparts. rod rcsults coosistcotly sàow dctc¡iorarioa of perfonnane oo tþ night shifr.
Brownc (1949) studicd tclcphooc opcfitotls' rÊspoos€ ti¡æ in urs*rring incoming ç¡n< i¡ ¡elaioo
ro thc bor¡r of thc day and fo¡nd tbc loges rc.spoose ti¡rrs occurred be¡wccn 03æ a¡rd O46p
bours. Bixær et ¡1. ( 1955) erami¡cd tas company horly lcdgcr corlFrtarions of gas prodgccd
æd gas uscd over an lt-year pcrid a¡d for¡nd tba rccording error werc highesr u 03@ bou¡s
sirh a smallcr sccondary pcak at l5OO bor¡¡s. Hildcbrar¡dt e¡ d. (1971). investigating automatic
úain br¿krng and acorstical warai¡g signal alarrm sct-offs, dso for¡¡d rwo peats ¡r O36p ¡¡rd
l5O0 bor¡n in thcsc safety-rclatcd eveDÈ¡. Simila¡ 6nding have bcca rcponcd in tn¡ck accidco¿s
tTlarris, 1977) and in Ai¡ Forcc ai¡crañ æcidcots (R.ibak e¡ d., l9t3). Orbcr accidenr analyscs of
unr of da¡ and hours of wort show thu both ci¡cadian ràyttr¡n a¡d bor.¡¡s of dury ptay I
srgrul-rc¿¡r role rn the ct-currence of accidenrs (Folþ¡d, 1997:L¡noee¡ al.. 1997). tn addirion. the
rncidencc of accrdental lDJury nea¡lv dor¡bles dunog the nrght shrft compared ro morning shjfr-
*blc tbc screnty of in.¡ury i¡crascs 23 pcrccot (Sro¡th ct al.. 1994). .\rghr nu.rses mate ocarly
¡¡ice the pancnt mcdicauon enors as da-r'Du¡ses a.od expcncnce nca¡h ùrec urrrs the auto
¡ccrdenrs,-ornmutins to a¡¡d from *'ork (Gold et al . 19931
\Ìerstedr,l9tElrevie'*ed the effects of slecpincss riom nr_ehr shfr nork and found rha¡ rhe
¡.æntrallr
hazardous srrualron rcsulting from i¡cre¡-çcd slceprness durug rught shift is real a¡¡d
rrnderestrma¡ed. Akerstcdt (l98tl dso rcports rhar faugue rn sh¡fr *orters s h:gtrcr than io day
trorkers. hrghest in night workers. follorred by mornmg workers. OvenJl. stccprncss ¿unont rughr
sorkers is estLmated to bc a¡ound 8O to 9O pcrcent Roth er d. (1991) i¡dicarc tha¡ rates for
r¡orkers falLng aslecp on the job
'rhiJe oo night sluft havc bccn rcponal ro bc as high as 20
Pcrcent.
Sight operarions are physiologicalJy different than day opcraùons due to ci¡cadian trough and
slccp loss. This ca¡rics a higher pbysiologic^l cost and impors grcårcr risks of accidcnts. One of
thc most est¡blished safety issues is working in thc cúcadian ¡roueh bcr*'ecn 0200 and 0600.
h.rring thx priod worken cxpcriencc considerable sleepiness. sloner rcsponsc ti¡nes. increascd
errors a¡¡d accidcnu (Mitler. l99l: Pack. 1994) Ilan¡'recent accidens from va¡ious
uansporution modes hare bccn associa¡ed '*'ith thjs cr¡cadian trough (L¿ubcr & Karren. l98t).
Literature R¿r'i¿x Page 24