submission - Independent Pilots Association

Other Variables
tndividual Differences In Sleep Requirements. Many of the srudies describcd above showed
that there appears
iliry in individual sleep necds. Thus, the eight'hour
slee p rcqui¡erncn¡
lecp nceds, but does not take into account of the
n"".i, o¡hosc ind
onal slecp and who represcnt a fair perccnt of thc
population.
Age-Reletcd Ctanges
nightly slccp dr.rc to inc
1980; Carskadon ct al.,
individuals. habiruat nigbniræ slccp is ¡ìccomP¿u
dosing. and napping.Thit incre¿sc in
quantrry and appcÁ to indicatc that s
tif.tim. Miles & Dement' 1980; FIab
næmbe rs may have particular diñìculties in achie
schedule (cf. Ca¡skadon, Broum & Dcrncnt, 1982)'
normal slecp
person's adult
older crcw
a normal dury
Logist¡cål Issues. A number of srudies have investrgated thc issue of the amount of slecp that is
,.*^tty achrere,J as a function of rhc length of the off-dury p€nd Tbcs€ studies demonsLrate
tbar ofidurl, penods rhat appcar to provide an acceprable slee p oppornrnitl may not' in rcaliry' bc
sufficienr. In one srudy...àú.uont in slccp of t*'o to th¡eehou¡s pr24 bou¡s occurrcd when tbc
r rme be r* ee n shrfts oi work was rcduccd to only' n ine hor¡¡s (Knauth, l9t3). In the NASA srud ies
of shon.haul prJou (Gander et al . 199.1:Gander & Graebe r, 1994), pilos reported an average of
ll 5 hou¡s off-durl rinr bet*een dutr penods, but onJ¡ obained 6.7 bou¡s rcst.
Obsen auons of nurses on l2 hou¡ shifu *ork-rng ll.5 hours * irtr I I .5 hours off bctri'etn shrlts
obtaine,J an a\.erage of 6 9 hours sleep (Ìvfills er d.. 1983). ,q.nother srudy of long-haul and short
haul-rruck dnrers 1,1yRAJR, l997lsho*ed that short-haul drirers r¡irh sirrula¡ rest penods
bet*'een shifu obtained ercn fe*er slecp durations
Commercial rn¡ck drivers' (FI{\I'A, 199ó; Mirler et al., 1997) sleep/off duty schedules a¡e shor¡¡
i¡ Table l. \\'hen rruckers (cl-10) had 10.7 houn off dutl'bet*een l0 hourday shifts, sleep
durarions of onJy 5.4 hours werc achieved. On a l3-hour day shift (C1'13) with 8'9 hours off
berw.een duty periods. sleep durarions averagcd 5.1 hours. On l0-hou¡ routing shifts (C2'10) uith
g.7 houn off dur¡ , the sleep rinre r+ as 4.8 hours and after a I 3-hour night shift (C3- l 3) witÌ¡ 8.6
hours off. rhe re sulting sleep diminished to only 3.8 hours. In quick changeovers *'ith 8 hours off
ber*.een shifu. Tonerde¡ tigg0lfound rhat *orkers only acquired 5.1-l hours sletp. Kurumata¡r
r 199{) found a;crrelauon (r=.95)berween the hours betr*een shtft and sleep duration. The¡
Lileralure R¿t lf r.
tual
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