opter ▁was ▁more ▁of ▁a ▁" proof - of - con cept " ▁aircraft ▁than ▁a ▁true ▁prototype . ▁F irth ▁Hel ic op ters ▁Ltd . ▁had ▁obtained ▁rights ▁to ▁the ▁Land g raf ▁pat ents ▁regarding ▁a ▁concept ▁which ▁involved ▁tw in ▁out r igger ▁p yl ons ▁carrying ▁three - bl aded ▁rot ors ▁fitted ▁with ▁a iler ons ▁to ▁change ▁direction . ▁▁ ▁The ▁design ▁team ▁of ▁He en an , ▁W inn ▁and ▁Ste ele , ▁led ▁by ▁Major ▁J . N . ▁D und as ▁He en an ▁who ▁had ▁been ▁previously ▁involved ▁in ▁a ▁similarly ▁un orth odox ▁ 1 9 4 8 ▁aircraft ▁project , ▁the ▁Planet ▁Sat ellite , ▁util ized ▁the ▁fus el age ▁of ▁the ▁second ▁Sat ellite ▁prototype , ▁registered ▁G - AL X P ▁in ▁ 1 9 5 1 . ▁The ▁small , ▁stream lined ▁Sat ellite ▁mon oco que ▁fus el age ▁consisted ▁of ▁pan els ▁of ▁an ▁extremely ▁light ▁mag nes ium - z ir con ium ▁al loy . ▁The ▁original ▁cont ours ▁t aper ed ▁to ▁a ▁but ter fly ▁tail ▁that ▁was ▁elimin ated ▁and ▁replaced ▁by ▁a ▁single ▁fin ▁to ▁be ▁to pped ▁by ▁a ▁tail plane ▁in ▁a ▁" T ▁tail " ▁design ; ▁surprising ly , ▁the ▁Sat ellite ▁fus el age ▁was ▁integrated ▁se am lessly ▁into ▁the ▁new ▁hel ic opter ▁plan form . ▁ ▁The ▁Sat ellite ' s ▁four - se at ▁configuration ▁allowed ▁for ▁a ▁larger