▁was ▁mounted ▁with ▁considerable ▁nose - down ▁angle ▁to ▁ensure ▁prop - w ash ▁over ▁the ▁rot or ▁to ▁maintain ▁rotation ▁and ▁ease ▁rot or ▁starting . ▁ ▁Control ▁of ▁the ▁aircraft ▁was ▁achieved ▁only ▁by ▁use ▁of ▁the ▁thro tt le ▁and ▁the ▁til ting ▁rot or - head , ▁operated ▁by ▁a ▁h anging ▁control ▁stick ▁in ▁the ▁rear ▁co ck pit . ▁ ▁Oper ational ▁history ▁The ▁Y G - 2 ▁and ▁OP - 2 ▁were ▁briefly ▁tested ▁by ▁the ▁US ▁Army ▁and ▁US ▁Navy , ▁with ▁limited ▁success . ▁After ▁comple ting ▁tests ▁with ▁the ▁US ▁Army , ▁the ▁Y G - 2 ▁was ▁taken ▁over ▁by ▁the ▁National ▁Ad vis ory ▁Committee ▁for ▁Aer onaut ics ▁( N AC A ). ▁registered ▁as ▁N AC A ▁ 8 8 . ▁On ▁ 3 0 ▁March ▁ 1 9 3 6 , ▁whilst ▁on ▁test , ▁N AC A ▁ 8 8 ▁suffered ▁a ▁rot or ▁failure , ▁prompt ing ▁the ▁crew ▁to ▁perform ▁the ▁first ▁successful ▁b ail - out ▁from ▁a ▁rot ary - wing ed ▁aircraft . ▁ ▁Vari ants ▁PA - 3 3 ▁Company ▁design ation ▁of ▁the ▁Y G - 2 ▁for ▁the ▁US ▁Army ▁PA - 3 4 ▁Company ▁design ation ▁of ▁the ▁OP - 2 ▁for ▁the ▁US ▁Navy ▁Y G - 2 ▁US ▁Army ▁tri als ▁aut ogy ro ▁( PA - 3 3 ), ▁ 1 ▁built . ▁X OP - 2 ▁US ▁Navy ▁tri als ▁aut ogy ro ▁(