▁Y C - 1 3 0 ▁Her cules ▁which ▁served ▁as ▁the ▁basis ▁for ▁a ▁classic ▁series ▁of ▁tact ical ▁trans ports ▁that ▁would ▁continue ▁in ▁front line ▁service ▁until ▁well ▁into ▁the ▁ 2 1 st ▁century . ▁It ▁also ▁supported ▁the ▁development ▁of ▁the ▁extremely ▁high - alt itude ▁and ▁long - range ▁Lock he ed ▁U - 2 ▁and ▁the ▁d azz ling ▁ult ra - per formance ▁capabilities ▁of ▁the ▁B - 5 8 ▁H ust ler , ▁the ▁world ' s ▁first ▁Mach ▁ 2 ▁bom ber . ▁ ▁Through out ▁the ▁ 1 9 5 0 s , ▁American ▁air plan es ▁regularly ▁broke ▁absolute ▁speed ▁and ▁alt itude ▁records ▁at ▁Edwards , ▁but ▁nothing ▁compared ▁to ▁the ▁arrival ▁of ▁the ▁North ▁American ▁X - 1 5 ▁in ▁ 1 9 6 1 . ▁The ▁program ▁got ▁under way ▁in ▁earnest ▁in ▁ 1 9 6 1 ▁when ▁Maj . ▁Robert ▁M . ▁" Bob " ▁White ▁became ▁the ▁first ▁man ▁to ▁exceed ▁Mach ▁ 4 , ▁as ▁he ▁acceler ated ▁to ▁ ▁on ▁ 7 ▁March . ▁He ▁claimed ▁Mach ▁ 5 ▁just ▁three ▁months ▁later ▁when ▁he ▁p eg ged ▁a ▁speed ▁of ▁ ▁on ▁ 2 3 ▁June ▁and ▁then , ▁during ▁the ▁X - 1 5 ' s ▁first ▁full - power ed ▁flight ▁on ▁ 9 ▁November , ▁he ▁exceed ed ▁Mach ▁ 6 , ▁as ▁he ▁fle w ▁to ▁a ▁speed ▁of ▁. ▁Major ▁White ▁also ▁became ▁the ▁first ▁man ▁to