uring ▁the ▁four ▁conditions ▁listed ▁above . ▁Cost : ▁A ▁flight ▁test ▁is ▁extremely ▁cost ly ▁and ▁therefore ▁the ▁goal ▁is ▁to ▁minim ize ▁any ▁development ▁occurr ing ▁with ▁flight ▁test . ▁D uration : ▁Develop ing ▁flight ▁controls ▁with ▁flight ▁test ▁will ▁extend ▁the ▁duration ▁of ▁an ▁aircraft ▁development ▁program . ▁Using ▁H IL ▁simulation , ▁the ▁flight ▁controls ▁may ▁be ▁developed ▁well ▁before ▁a ▁real ▁aircraft ▁is ▁available . ▁Saf ety : ▁Using ▁flight ▁test ▁for ▁the ▁development ▁of ▁critical ▁components ▁such ▁as ▁flight ▁controls ▁has ▁a ▁major ▁safety ▁imp lication . ▁Should ▁errors ▁be ▁present ▁in ▁the ▁design ▁of ▁the ▁prototype ▁flight ▁controls , ▁the ▁result ▁could ▁be ▁a ▁crash ▁landing . ▁Fe as ibility : ▁It ▁may ▁not ▁be ▁possible ▁to ▁explore ▁certain ▁critical ▁tim ings ▁( e . g . ▁sequences ▁of ▁user ▁actions ▁with ▁mill isecond ▁precision ) ▁with ▁real ▁users ▁operating ▁a ▁plant . ▁Like wise ▁for ▁problem at ical ▁points ▁in ▁parameter ▁space ▁that ▁may ▁not ▁be ▁easily ▁reach able ▁with ▁a ▁real ▁plant ▁but ▁must ▁be ▁tested ▁against ▁the ▁hardware ▁in ▁question . ▁ ▁Use ▁in ▁various ▁discipl ines ▁ ▁Autom ot ive ▁systems ▁ ▁In ▁context ▁of ▁autom ot ive ▁applications ▁" H ard ware - in - the - loop ▁simulation ▁systems ▁provide ▁such ▁a ▁virtual ▁vehicle ▁for ▁systems ▁validation ▁and ▁ver ification ." ▁Since ▁in - ve h icle ▁driving ▁tests ▁for ▁evalu ating ▁performance ▁and ▁di agnostic ▁functional ities ▁of ▁Engine ▁Management ▁Systems ▁are ▁often ▁time - consum ing ,