▁did ▁not ▁start ▁immediately . ▁Lic enses ▁were ▁passed ▁from ▁company ▁to ▁company ▁before ▁finally ▁sett ling ▁at ▁Domin ion ▁Scient ific ▁Inst ru ments ▁( D SI ) ▁of ▁Ott awa . ▁They ▁contract ed ▁Le igh ▁Inst ru ments ▁of ▁Car leton ▁Place ▁to ▁manufact ure ▁the ▁system . ▁ ▁C PI ▁was ▁soon ▁mand atory ▁on ▁Canadian ▁Air ▁Force ▁aircraft ▁working ▁in ▁the ▁far ▁north . ▁In ▁one ▁instance , ▁an ▁aircraft ▁in ▁the ▁Y uk on ▁mountains ▁was ▁found ▁by ▁C PI ▁in ▁a ▁location ▁where ▁visual ▁location ▁would ▁have ▁been ▁impossible . ▁In ▁another , ▁a ▁US AF ▁aircraft ▁crash ed ▁into ▁the ▁ocean ▁at ▁night , ▁but ▁its ▁injured ▁crew ▁was ▁res cu ed ▁after ▁the ▁C PI ▁broadcast ▁was ▁detected . ▁Le igh ▁received ▁a ▁letter ▁of ▁thanks . ▁Even ▁Air ▁Force ▁One ▁was ▁equ ipped ▁with ▁a ▁C PI , ▁the ▁AN / ASH - 2 0 . ▁ ▁A RL ' s ▁flight ▁memory ▁While ▁Ste vin son ▁was ▁working ▁on ▁the ▁" t umb ling ▁aer of o il ▁be acon ", ▁David ▁Warren ▁of ▁the ▁Aer onaut ical ▁Research ▁Labor ator ies ▁( AR L ), ▁Australia ' s ▁counter part ▁to ▁the ▁Canadian ▁NA E , ▁was ▁developing ▁the ▁concept ▁of ▁the ▁co ck pit ▁voice ▁rec order ▁under ▁the ▁name ▁" F light ▁Memory ". ▁In ▁ 1 9 5 8 ▁he ▁visited ▁the ▁N RC ▁to ▁discuss ▁the ▁possibility ▁of ▁incorpor ating ▁the ▁Fl ight ▁Memory ▁system ▁into ▁the