▁SR . 1 7 7 , ▁the ▁latter ▁being ▁worked ▁on ▁by ▁a ▁newly ▁formed ▁High ▁Speed ▁Development ▁Section . ▁ ▁Oper ational ▁history ▁ ▁In ▁October ▁ 1 9 5 1 , ▁Sau nd ers - R oe ▁obtained ▁facilities ▁at ▁R AF ▁H urn , ▁Dor set , ▁to ▁support ▁the ▁site ' s ▁use ▁as ▁a ▁base ▁for ▁test ▁fl ights ▁of ▁the ▁SR . 5 3 . ▁This ▁measure ▁had ▁been ▁necess itated ▁by ▁a ▁lack ▁of ▁suitable ▁air fields ▁on ▁the ▁Is le ▁of ▁W ight , ▁where ▁the ▁company ▁was ▁based ▁and ▁typically ▁conducted ▁development ▁from . ▁To ▁this ▁end , ▁the ▁firm ▁constructed ▁a ▁HT P ▁storage ▁fac ulty ▁at ▁the ▁H urn ▁site ; ▁special ised ▁radio ▁a ids ▁were ▁also ▁installed ▁and ▁initially ▁tested ▁using ▁a ▁spe cially - mod ified ▁G loster ▁Meteor ▁which ▁had ▁been ▁l ent ▁by ▁the ▁Ministry ▁of ▁Supp ly . ▁This ▁setup ▁would ▁ultimately ▁remain ▁un used ▁as ▁flying ▁tri als ▁were ▁centered ▁at ▁R AF ▁Bos com be ▁Down ▁instead . ▁ ▁On ▁ 2 8 ▁June ▁ 1 9 5 6 , ▁the ▁completed ▁first ▁prototype , ▁X D 1 4 5 , ▁was ▁dispatch ed ▁for ▁assembly ▁by ▁the ▁Aer op lane ▁and ▁Arm ament ▁Ex perimental ▁Est ab lish ment ▁at ▁R AF ▁Bos com be ▁Down . ▁On ▁ 1 6 ▁January ▁ 1 9 5 7 , ▁the ▁first ▁installed ▁ground ▁run ▁of ▁its ▁Spect re ▁engine ▁was ▁performed ; ▁on ▁