submission - Independent Pilots Association

The effect of unr srnce ¡he last slctp rs c\en grceter ¡f a slccp debr alrc¿d.r e\rsLs. A¡ NTSB
hcavy trucks accident ana.lysis (NTSB. 199ó) clearly shou s that "back of rhe ctock" dnr ing u.irh
a slecp debr caries a very high nsk Of 107 singlc-rehrclc tnrck a.'cidenrs. l- dnrers.r..i.J.d
rhc horlrs of dury. lrinery-two pcrccDt rló) of thcsc had fatrgue-relared acc¡denrs The .¡-TSB
rcpon also shows that 67 pcrccnt of m¡ck drivc¡s with irregular dur¡' or slecp pencrns had farigucrclaed
æcidcnts compared to 3t pcrcent in drivcrs with regular dury or slæp panerns.
trregularity resulted in a dccreasc of 1.6 bor¡¡s on averate in slccp wirh a rotal of onty 6. I hor¡¡s
compared ao7.7 bor¡rs ia regular petlcro drivers. Thc IiTSB report indicacd thar tlrcy could oot
dctcrmiæ wh.lbcr irregular dury/slccp Peltcros pc¡ se lcd to fetigue but rcræ erpcrirænrå¡ da¡a
e¡ppon ùb Dotioo. Tbe 6ndings of fu NTSB oot only fouod shiñod slccp p.r¡crDs but rhis shiñ
*rs couplod witb slccp lc. Tr¡¡b æd B€ger (1974), whiþ rnai¡¡einint s¡ccp leogth, shiftcd
slæp rirrrçs ¡od fqnd thrt pcrfornæ o vigileoc+ cjcr¡t¡tioo r-d¡r, ¡¡d mæd ¡æ¡e
sigÊific¡dy uryr1ea. R¡nhsuaq Nlúolson ct d. (19t3) shonæd thu inegutar slccy'wort
rcsultcd i¡ increasing pcrforrnanca inpdræots wfiich clas ñ¡Íùcr increascd by tinr on task.
cumulative slecp loss. a¡d working througb tbc ci¡cadia¡ nadi¡.
Perforrna¡cc c¿¡ dso bc affedcd b¡'curoulaive fadgue buildup across multiple days. Gundel
( 1995) for¡nd that pilots flying rwo coosccutive nighs wirå 24 hor¡rs bc¡u,cca fligbs stepr abour
rwo and a half bot¡rs þss dr¡ring tÞir deytirrE layovcrs (t.66 hor¡¡s yensus 6.15 bours), and
erperieoccd a signiñcant dcclinc i¡ elcræss oo the sccood night ftight. Alerocss d'ring tþ fi¡st
sü bou¡s i¡ boû flights appeared lo bc thc saæ. Tbc laucr part of thc sccood flighr shoied
increascd dcsylchronizatioo of EEG dpba wave activit-v. indicating lowcr lcvcls of alersress.
Spontancotrs dozing indicared a¡ i¡cre¿scd surc¡ibihq slecp Subjecùvel¡. pilos fclr grearer
fatigue on the sccood night. Tbercfore. wrtb trrrr slnce auake berng the sarnc. slecp qualiq,a¡d
quantir,v duriog tbc da¡irnc layovcr resuJtcd i¡ incre¿scd fa-riguc.
Sarncl et al. (1997) monitorcd I I rusbt fìight rotatrons hom Fra¡rkfon ro.\la}e/Se',chelles
crosslng tì¡ec tiræ zones Pilos slc¡ oo ayerage ergbt hu.rn on b¡scbne rught5 On laror.er.
slecp *as reduccd to ó.3 bours. Prle\s arnved a SFZ aficr ll hor¡rs of Þmg ar¡.ake (crccpr fcr
approxirnatc L5 hou¡ nap prior to dcpernrre;. Fatrgue s*-oîes increased orcr borh outbounà anC
rnbound flighrs with 12..1 micro-slccps pcr pi.lot outbouod au;'d2a.1 on rerurn. hior ro r11c
outbor¡nd FR A'-SU flight t5 pcrccot of pilos felt rcstcd n hereas on reruÍn onJy 30 pcrcenr
rcported fccling so. Tt¡csc str¡dics dæurænt t-hat nighr fì.¡-shs a¡e associarcd * ith reduccd slecc
quantity and qualiry, alrd are accorDpanicd by cumula¡ire sleep debr.
Boro*'sþ and t#all (19t3) found t-ba flight-rclated accidcnts in \avy agcrafr *ere significanrly
higher in flighu originating bct*cca 240O a¡d 0ó00 houn. The higher m,ishap incidencc was feir
to bc the rcsult of ci¡cadia¡l dcsynchrooiz¡ûon and disruprcd slecp-uake c¡-cte. Sharppcll urd
Neri ( 1993) divided the opcrationd day of navy pilos in Desen Shield and Descn Srorm
opcrations i¡ to for¡¡ quartiles bcgrnÃing u 06O I - 1200 uirh 0001 ro 06O0 bcin_e rhe fou¡rh
quartile. Thcy found that therc $as a progrÊssive [¡ç¡ç¿5. in pilou' sublccúr'e need for resr
bctr+een fligbts as flighs originated later a¡d la¡er in rhc dar from quanile I ¡o qua¡ile 4. In
Literature Rer iex
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