▁were ▁reconna issance ▁auto - gy ros ▁designed ▁and ▁built ▁in ▁ 1 9 3 6 ▁for ▁evaluation . ▁ ▁Design ▁and ▁development ▁The ▁Pit ca ir n ▁A ircraft ▁Company ▁built ▁and ▁developed ▁auto - gy ros ▁under ▁lic ence ▁from ▁the ▁C ier va ▁Aut og iro ▁Company , ▁trad ing ▁as ▁the ▁Pit ca ir n - C ier va ▁Aut og iro ▁Company ▁from ▁the ▁late ▁ 1 9 2 0 s . ▁Interest ▁in ▁the ▁auto - gy ro ▁by ▁the ▁US N ▁resulted ▁in ▁the ▁purchase ▁of ▁two ▁Pit ca ir n ▁P CA - 2 ▁aut ogy ros , ▁modified ▁as ▁two - se at ▁observation ▁platforms , ▁designated ▁X OP - 1 . ▁Tri als ▁with ▁the ▁X OP - 1 s ▁from ▁ 1 9 3 1 ▁had ▁limited ▁success , ▁but ▁included ▁an ▁oper ational ▁deployment ▁in ▁Nic ar agua ▁from ▁June ▁ 1 9 3 2 , ▁with ▁the ▁United ▁States ▁Marine ▁Corps ▁( US MC ). ▁ ▁Following ▁the ▁development ▁of ▁much - im pro ved ▁rot or ▁and ▁control ▁systems , ▁further ▁interest ▁by ▁US ▁armed ▁forces ▁resulted ▁in ▁the ▁Pit ca ir n ▁PA - 3 3 ▁( Y G - 2 ) ▁and ▁Pit ca ir n ▁PA - 3 4 ▁( X OP - 2 ). ▁These ▁essentially ▁identical ▁aircraft ▁differ ed ▁mainly ▁in ▁under car riage ▁design ; ▁the ▁PA - 3 3 ▁had ▁fully ▁cant ile ver ed ▁o le o - p neum atic