▁ ▁With ▁the ▁development ▁contract s ▁cancel led ▁in ▁June ▁ 1 9 4 3 , ▁the ▁program ▁ended ▁ign ob ly ▁when ▁the ▁last ▁prototype ▁was ▁scra pped ▁on ▁ 2 2 ▁December ▁ 1 9 4 4 . ▁To ▁replace ▁the ▁P - 6 0 , ▁Curt iss ▁built ▁ 3 5 4 ▁Republic ▁P - 4 7 G s ▁instead ▁for ▁the ▁USA AF . ▁The ▁XP - 6 0 E ▁surv ived ▁to ▁be ▁sold ▁as ▁an ▁entry ▁for ▁the ▁ 1 9 4 7 ▁National ▁Air ▁R aces , ▁but ▁crash ed ▁during ▁a ▁qual ifying ▁flight ▁before ▁the ▁competition ▁was ▁held . ▁ ▁Vari ants ▁ ▁XP - 5 3 ▁Curt iss ▁Model ▁ 8 8 ; ▁derivative ▁of ▁XP - 4 6 ▁to ▁Request ▁for ▁Data ▁R 4 0 - C ▁specific ations . ▁L amin ar ▁flow ▁wing ▁and ▁Cont inental ▁XIV - 1 4 3 0 - 3 ▁engine . ▁Cont ract ed ▁for ▁ 1 ▁October ▁ 1 9 4 0 ; ▁cancel led ▁in ▁favor ▁of ▁XP - 6 0 ▁in ▁November ▁ 1 9 4 1 . ▁Two ▁built , ▁one ▁converted ▁to ▁the ▁XP - 6 0 , ▁the ▁other ▁used ▁as ▁a ▁static ▁test ▁air frame . ▁XP - 6 0 ▁Curt iss ▁Model ▁ 9 0 ; ▁Roll s - Ro y ce ▁Mer lin ▁engine , ▁arm ament ▁ 8 ▁. 5 0 - cal ▁machine ▁guns . ▁One ▁built , ▁first ▁flight ▁ 1 8 ▁September