▁North ▁American ▁Y P - 8 6 ▁flow n ▁by ▁George ▁Wel ch ▁becomes ▁the ▁first ▁American ▁f ighter ▁aircraft ▁to ▁exceed ▁Mach ▁ 1 . ▁During ▁a ▁long - range ▁test ▁flight ▁that ▁covers ▁ 3 , 5 2 8 ▁miles ▁( 5 , 6 8 1   km ) ▁in ▁ 9 ½ ▁hours ▁over ▁a ▁round - ro bin ▁course ▁over ▁California ▁and ▁Arizona ▁at ▁a ▁true ▁air speed ▁of ▁ 3 8 8   m ph ▁( 6 2 5   km / hr ), ▁the ▁U . S . ▁Air ▁Force ' s ▁first ▁North rop ▁Y B - 4 9 ▁jet - power ed ▁flying ▁wing ▁bom ber ▁prototype ▁sets ▁an ▁end urance ▁record ▁for ▁sust ained ▁flight ▁above ▁ 4 0 , 0 0 0 ▁feet ▁( 1 2 , 1 9 2 ▁meters ), ▁remaining ▁above ▁that ▁alt itude ▁for ▁ 6 ½ ▁hours . ▁ ▁April ▁ 2 8 ▁– ▁The ▁U . S . ▁Navy ▁launch es ▁two ▁P 2 V - 3 C ▁Ne pt une ▁aircraft ▁– ▁a ▁version ▁of ▁the ▁P 2 V ▁configured ▁for ▁car rier ▁launch ▁carrying ▁a ▁nuclear ▁weapon ▁– ▁from ▁the ▁aircraft ▁car rier ▁ ▁off ▁the ▁coast ▁of ▁Virginia . ▁The ▁first ▁car rier ▁launch es ▁of ▁any ▁type ▁of ▁P 2 V , ▁they ▁establish ▁the ▁U . S . ▁Nav ys ▁first , ▁inter im ▁car rier - based ▁nuclear ▁strike ▁cap ability ▁pending ▁the ▁ac quisition ▁of ▁aircraft ▁designed ▁from ▁the ▁out