▁C PI . ▁ ▁At ▁the ▁time , ▁Warren ' s ▁device ▁had ▁not ▁been ▁built , ▁and ▁when ▁they ▁finally ▁had ▁a ▁unit ▁ready ▁for ▁testing ▁in ▁ 1 9 6 2 , ▁they ▁found ▁that ▁D SI ▁had ▁already ▁developed ▁a ▁" very ▁nice " ▁system ▁providing ▁" voice , ▁time , ▁and ▁ 9 6 ▁data ▁channels ▁… ▁on ▁ ¼ ▁in ch ▁t ape ." ▁Sur pr ised ▁by ▁this ▁development , ▁A RL ▁never theless ▁requested ▁one ▁of ▁the ▁air frames , ▁and ▁showed ▁it ▁with ▁Fl ight ▁Memory ▁at ▁a ▁trade ▁show ▁in ▁ 1 9 6 3 . ▁ ▁D SI ' s ▁system ▁would ▁go ▁on ▁to ▁spawn ▁a ▁series ▁of ▁models , ▁some ▁in ▁C PI ' s ▁and ▁some ▁in ▁rug ged ized ▁crash - sur viv able ▁forms . ▁ ▁Com mer cial ▁success , ▁business ▁failure ▁By ▁the ▁ 1 9 7 0 s , ▁the ▁C PI ▁with ▁data ▁rec order ▁was ▁now ▁a ▁standard ▁item ▁on ▁many ▁Canadian ▁and ▁US ▁aircraft , ▁and ▁would ▁also ▁be ▁selected ▁for ▁the ▁Pan avia ▁T orn ado . ▁It ▁was ▁optional ▁on ▁many ▁other ▁aircraft , ▁and ▁fairly ▁common ▁on ▁bush ▁plan es . ▁Its ▁success ▁was ▁such ▁that ▁Le igh ▁eventually ▁purchased ▁D SI , ▁and ▁by ▁ 1 9 7 8 ▁year ly ▁sales ▁of ▁modern ▁C PI ▁devices ▁were ▁$ 6 ▁million . ▁Total ▁sales ▁over ▁the ▁years ▁to pped ▁$ 1 0 0 ▁million . ▁Le igh ▁became