▁a ▁project ▁led ▁by ▁Bo eing ▁that ▁used ▁a ▁Diam ond ▁H K 3 6 ▁Super ▁Dim ona ▁motor ▁gl ider ▁as ▁a ▁test bed ▁for ▁a ▁fuel ▁cell - power ed ▁light ▁air plane ▁research ▁project . ▁The ▁project ▁achieved ▁level ▁flight ▁using ▁fuel ▁cells ▁only ▁in ▁February ▁and ▁March ▁ 2 0 0 8 . ▁ ▁In ▁December ▁ 2 0 1 6 ▁there ▁were ▁nine ▁H 3 6 s ▁and ▁thirty ▁H K 3 6 s ▁registered ▁with ▁the ▁US ▁F AA , ▁two ▁H K 3 6 R s ▁and ▁two ▁H K 3 6 T TS s ▁registered ▁with ▁Transport ▁Canada , ▁along ▁with ▁seven ▁H 3 6 s ▁and ▁eight ▁H K 3 6 s ▁registered ▁with ▁the ▁UK ▁Civil ▁A viation ▁Author ity . ▁ ▁Vari ants ▁H 3 6 ▁Dim ona ▁Original ▁version ▁produced ▁by ▁Hoff mann ▁and ▁later ▁by ▁HO AC , ▁with ▁a ▁ ▁wings pan , ▁conventional ▁landing ▁g ear , ▁ 2 7 : 1 ▁gli de ▁ratio ▁and ▁power ed ▁by ▁a ▁Lim bach ▁L 2 0 0 0 ▁E B 1 C ▁engine ▁of ▁, ▁a ▁Rot ax ▁ 9 1 2 A ▁of ▁ ▁or ▁Lim bach ▁L 2 4 0 0 ▁E B ▁of ▁. ▁App lied ▁for ▁US ▁F AA ▁certificate ▁on ▁ 4 ▁April ▁ 1 9 8 2 ▁and ▁received ▁on ▁ 9 ▁July ▁ 1 9 8 6 ▁in ▁the ▁utility ▁category ▁at ▁a ▁gross ▁weight ▁of ▁. ▁ ▁H K 3 6