submission - Independent Pilots Association

shift uorken (Colligan & Tepas. l9tó). nrght sfuft *orkcn (Rosa á! Collrgan. 1987). ra *atch
r¡orkers lColquhoun. 1985). and truck dnvers (Hanrlin. l9t7). The laner srudv also found an
lncre¡Lr tn the numbcr of accidents that a'cur *hen I l'hour shifts arc uscd-
This increascd likelihood of accidcnt risk duc to long duty pcnods has bccn found in othcr
s¡udics. Thc relarive risk of an accidcnt. ¡¡¡ l4 hot¡¡s of dury riscs to 2.5 tirnes tha of ütc lowest
pornr in ¡lc f'rst eighr hor¡rs of duty. Askertedt (1995) rePons accidcot risks to bc th¡ecfold a¡ 16
-hou¡5
of dury. whiþ Harris and M¡ckie ( 1972) fo¡nd r ¡hrecfold nsk in jut over l0 bor¡rs of
driving. TÌrcsc þvels of rist are simil¡r to ¡bat æsociarcd with b¡vi¡¡ oercolepsy or slccp rpæ¡
(L¡vþ et 1., l9t2), or I blood dcoùol level of 0.10 pcrccnt Wegrnann et al. (19t5), i¡ ¡ study of
ai¡ carrie¡ pilots, rrgr¡cd for a duty pc¡iod of t0 bot¡¡s with t.5 bor¡r¡ or þss of f,ight ûry pc¡iod.
Ti¡oc Sincc Aw¡ke
The rcsults of an NTSB analysis of donrstic ai¡ ca¡rier accidcnts æo¡¡rint from l97t to 1990
suggesr thar tirnc sincc arlale (TSA) was tlæ dominant fatiguc-rclaæd factor in ¡hcsc accidents
(NTSB. 1p!4). Pcrforrna¡cc dccrerncns of high tiræ-siocc-awake crewr æodcd to result from
ineffectivc dccision-m¡Þing ratlrcr tha¡¡ detcrior¡rion of ai¡crafr bandling skills. Tbcsc dccrcnæas
werc nor felr ro be rcla¡cd to tinp zone crossings si¡rcc all ¡ccidcns i¡volved sbort bad flighs
with a n¡a¡imum of two tinp zoncs crosscd. Thcre did appcar to bc rwo Pcåks in accidcos: in thc
moming whcn rin¡c since awake is low a¡ld the crcw has bccn on duty for abor¡t th¡ec to four
hou¡s. ¡"rd uhen tirnc-sincc-a*ale *as high. abore l3 hor¡¡s. Simila¡ accidcnt pcals in othcr
modes of transp'onatron and indust-q hare also bccn rcponcd Gotkerd. 1997). Alerstedt &
Keck1und (l9t9l srudied pnor trræ a*ale (fr-'ru¡to l2 hou¡s) and found astr-ong c_orrelation of
accrden,.s urrh rrnr srnce a\Àake for all orrrs of tàe da¡ Bclenþ er al. (19ç¿l found that fìrghr
trrne hours i,* L.r'idoad t greatlv tnr-reas€ a¡d ad'l to the linea¡ dccline rn performa¡ce associated
r¡rth t¡lr st-nce ar¡al