▁B ax ter ▁and ▁C . ▁W . ▁R . ▁Smith ▁at ▁F arn borough ▁review ed ▁the ▁ 1 9 4 0 ▁work ▁and ▁concluded ▁that ▁it ▁was ▁practical ▁but ▁problems ▁with ▁drag ▁and ▁pressure ▁loss ▁were ▁encountered ▁and ▁the ▁V 1 ▁had ▁been ▁be aten ▁before ▁they ▁were ▁solved . ▁ ▁Dim ensions , ▁performance ▁and ▁arm ament ▁Due ▁to ▁the ▁many ▁differences ▁in ▁production ▁Sp it f ires , ▁performance ▁could ▁vary ▁widely , ▁even ▁between ▁aircraft ▁with ▁the ▁same ▁Mark ▁number . ▁Fact ors ▁such ▁as ▁weight , ▁external ▁f itt ings , ▁air frame ▁and ▁engine ▁condition , ▁among ▁others , ▁influenced ▁how ▁an ▁aircraft ▁performed . ▁For ▁example , ▁even ▁relatively ▁minor ▁damage ▁on ▁the ▁wing ▁leading ▁edges ▁could ▁dr ast ically ▁reduce ▁top ▁speed . ▁The ▁most ▁reliable ▁performance ▁figures ▁and ▁weight ▁measurements ▁came ▁from ▁the ▁tests ▁carried ▁out ▁throughout ▁the ▁Second ▁World ▁War ▁by ▁the ▁Aer op lane ▁& ▁Arm ament ▁Ex perimental ▁Est ab lish ment ▁( A & AE E ) ▁based ▁at ▁Bos com be ▁Down . ▁ ▁Early ▁Mer lin ▁engines ▁ ▁Late ▁Mer lin ▁and ▁Griff on ▁ ▁Se af ire ▁ ▁References ▁ ▁Foot notes ▁ ▁Cit ations ▁ ▁Bibli ography ▁ ▁Air ▁Ministry . ▁A . P ▁ 1 5 6 5 ▁Sp if ire ▁I A ▁and ▁IB ▁Aer op lan es : ▁Mer lin ▁II ▁and ▁III ▁engines , ▁Pil ot ' s ▁Notes . ▁London : ▁Air ▁Ministry , ▁ 1 9 4 0 .