submission - Independent Pilots Association

Introduction
An Oven'ierc o[ the Scientific Literature
Concerning Fatigue. Sletp, and the Circadian C.r cle
Thjs docurncnr provides a bricf rcview of rhc scicntifìc resea¡ch relating to issues of pilot fatiguc
arising from crcw schcduling practiccs. A massive ¿rmount of rcsearch has bccn conducæd on
s¡cb iisues as thc cnvi¡onrncntal conditions that cootribuæ ¡o thc occt¡rrc¡ce of fatiguc, acute and
ch¡onic slccp debt and tlrci¡ effccts on pcrforrnancc. and thc inflrrcncc of tbc ci¡cadian cyclc on
alert¡rcss. This papcr attcmpts to idcotify major trcnds in this üærarr¡rc tbat might be of value in
addressing spþ6{ul i ng reguluory iss¡Ë.
Tbc papcr is organizcd i¡to scvcn scctioos. Tbc frnt scctioo,'\ilhat is Fatiguc," attcmPls !o
pro"idé a functional dcfinition of fatigr.rc that scrves to dehne thc scopc of issues thu necd to bc
considered, including variablcs that contributc to the occr,urence of fatigttc and rncthodologies for
asscssing the impact of fatigrrc on human functioning.
Scction two, "Indications and Efrects of FUigr.rc," briefly rcvicws the hurna¡l performancc and
pbysiologlcal i¡dicators of farigrrc. Tbc inænt is to idcnúfy possible dccrcmns in pcrformancc
that could bave a safery impact. This scction dso briefly add¡esscs the complcxitics involved in
rneasuring farigue levcls. As this scction cxplains. fuigue is a complex conc€Pt thar docs not
aJu.ays produce expected me¿surable de¡rcrnents in pe rformancc.
Scctionr¡rec, "Fariguc and thc Aviatioo Envi¡onment," add¡esscs tbc issue of fatiguc *ithjn the
aviationenvi¡onrnent. Beforc changes a¡e madc to existing regularions, tlre question of *hether
rhere is a problem that needs to be rcsolved should bc addresscd. Available research on the extent
ci farigue *ithln the aviation envi¡onrrrcnt s rcr'ie*ed. In addition. factors that compLicate the
assessrnent of the extent of the faUgue problem ln an oP€rational envltorìrDent a¡e also described
A piJor's lerel of alertness at any tinrc dcpcnds upon a complcx interactlon bet*ecn a number of
ya¡rables. Fou¡ va¡iables. in particular, nccd to þ considered: tin¡e on task. time si¡ce au'a-ke, any
exisring sleep debt. and tbe pi.lot's own ci¡cadian cycle. Scction fou¡. "Sta¡rdard Dury Period,"
descnbe s the resc¿rch trends pcrtairung to orne e¡ 1asft and un¡c si¡cc a'*'alie while scction fìr'e.
"Sra¡dard Slecp Requirenrnts," addrÊsscs Írcutc and ch¡oruc sleep debt, including
recommendations for slecp debt recovery. Scction sü, "The Circadian Cycle and Fuigue," which
looks ar rhe resca¡ch on ci¡cadian cycles and thei¡ implications for back'of-the