▁hel ic opter ▁than ▁the ▁Land g raf ▁H - 2 / H - 3 ▁series ▁( the ▁H - 4 ▁would ▁have ▁been ▁a ▁ 5 / 8 ▁passenger ▁hel ic opter ) ▁which ▁had ▁been ▁the ▁basis ▁of ▁the ▁first ▁Land g raf ▁concept ▁hel ic op ters . ▁The ▁tw in ▁non - art ic ulated ▁type ▁rot ors ▁were ▁power ed ▁by ▁two ▁ 1 4 5   hp ▁de ▁Hav ill and ▁Gi ps y ▁Maj ors . ▁ ▁Test ing ▁and ▁evaluation ▁In ▁ 1 9 5 2 , ▁F irth ▁Hel ic op ters ▁began ▁the ▁construction ▁of ▁the ▁F H - 0 1 / 4 ▁( st ill ▁registered ▁as ▁G - AL X P ) ▁at ▁their ▁Th ame , ▁UK ▁facilities . ▁Although ▁the ▁majority ▁of ▁the ▁work ▁had ▁been ▁completed , ▁technical ▁problems ▁with ▁excess ive ▁weight ▁on ▁the ▁anterior ▁part ▁of ▁the ▁rot ors ▁seemed ▁to ▁be ▁un sur mount able ▁given ▁the ▁limited ▁financial ▁resources ▁of ▁the ▁company . ▁Grad ually ▁work ▁ground ▁to ▁a ▁halt ▁without ▁final ▁equipment ▁being ▁installed ▁and ▁no ▁hope ▁for ▁a ▁first ▁flight . ▁The ▁F irth ▁F H - 0 1 / 4 ▁was ▁presented ▁to ▁the ▁College ▁of ▁Aer onaut ics ▁at ▁C ran field ▁in ▁ 1 9 5 5 . ▁ ▁Spec ifications ▁( F irth ▁Hel ic opter ) ▁Heaven ly ▁Body ▁ ▁L ength : ▁ 2 6   ft ▁ 3 ▁in ▁ ▁Height : ▁ 9  