^ 2 . ▁H yd ra ul ically ▁ret ract able ▁main ▁and ▁tail ▁under car ri ages ▁with ▁fully ▁closing ▁doors ▁reduced ▁drag ▁even ▁further . ▁ ▁Test ▁fl ights ▁began ▁in ▁January ▁ 1 9 3 9 ▁with ▁the ▁aircraft ▁on ▁sk is , ▁with ▁surprising ly ▁good ▁handling ▁and ▁man oe uv rab ility ▁as ▁well ▁as ▁excellent ▁performance . ▁ ▁Spec ifications ▁( SK - 1 ) ▁ ▁See ▁also ▁ ▁References ▁▁ ▁G unst on , ▁Bill . ▁“ The ▁O sp rey ▁Encyc lo pa edia ▁of ▁Russian ▁A ircraft ▁ 1 8 7 5 – 1 9 9 5 ”. ▁London , ▁O sp rey . ▁ 1 9 9 5 . ▁ ▁External ▁links ▁ ▁http :// www . av iation . ru / B is nov at / ▁ ▁Category : 1 9 3 0 s ▁Soviet ▁experimental ▁aircraft ▁SK - 1 <0x0A> </s> ▁USS ▁Nor folk ▁Pack et ▁was ▁a ▁large ▁sch oon er ▁purchased ▁by ▁the ▁Union ▁Navy ▁during ▁the ▁American ▁Civil ▁War . ▁ ▁She ▁was ▁assigned ▁to ▁gun bo at ▁duty ▁in ▁the ▁in land ▁water ways ▁of ▁the ▁Confeder ate ▁States ▁of ▁America . ▁ ▁P urchase ▁Sch oon er ▁Nor folk ▁Pack et ▁was ▁purchased ▁by ▁the ▁Navy ▁from ▁George ▁Good speed ▁of ▁New ▁York ▁City ▁ 1 0 ▁September ▁ 1 8 6 1 ; ▁alter ed ▁for ▁naval ▁service ▁by ▁J . ▁Eng les ; ▁and ▁commission ed ▁ 7 ▁February ▁ 1 8 6 2