ABSTRACT
TheCivilAviationAuthority(CAA),andparallelbodiesoverseas,existstoensure thatcivilaviationmaintainsanacceptablelevelofsafety.Theydothisby checkingthatalloftheelementsintheoverallcivilaviationsystemmeetbasic requirements,forexamplethestandardstowhichpilotsmustbetrained,aircraft areoperatedandairtrafficmanaged.Oneimportantelementthattheyassessis thedesignofnewormodifiedaircrafttypes.Thismustmeettheappropriate requirements(JointAviationRequirement[JAR]25forLargeAeroplanes)in ordertogaintheTypeCertificatethatwillpermitthemtobeoperatedbyairlines inthatcountry.JAR25islargelyfocussedontheairworthinessoftheaeroplane, andcontainsrequirementsforstrength,reliabilityandperformance.Italso containssomereferencestothewaythatthedesignaccommodatesthepilot,and requiresthattheprojectedpilotworkloadandskilllevelsarenotexcessive. Regulationsconcerningthese'HumanFactors'issuestendtoberathergeneral withlittleguidingdetailaboutwhatisandisnottobeconsideredacceptable. Theywerewrittenatatimewhenaircraftsystemsweresimplerandless sophisticated,integratedandautomated.Thecertificationteam,specificallythe testpilots,hastomakeajudgementandinterprettherequirementsforthemselves andsomeimprovementisneededtoaddressmodemaircraftflightdeckdesign (FAA,1996).
