▁He ▁ 1 7 7 ▁heavy ▁bom ber ▁project , ▁specifically ▁the ▁V 3 ▁and ▁V 4 ▁air frames , ▁be ▁set ▁aside ▁for ▁a ▁trial ▁installation ▁of ▁four ▁separate ▁J unk ers ▁J um o ▁ 2 1 1 ▁power pl ants . ▁ ▁He inkel ▁had ▁for ese en ▁that ▁an ▁individually ▁eng ined ▁version ▁of ▁his ▁bom ber ▁would ▁som ed ay ▁be ▁preferred , ▁quite ▁unlike ▁the ▁requested ▁fit ment ▁of ▁the ▁couple d ▁pairs ▁of ▁Da im ler - B enz ▁DB ▁ 6 0 1 ▁invert ed ▁V 1 2 ▁engines , ▁each ▁known ▁as ▁a ▁DB ▁ 6 0 6 ▁— ▁we igh ing ▁some ▁ 1 . 5 ▁t onnes ▁ap ie ce ▁— ▁which ▁ended ▁up ▁being ▁fitted ▁to ▁all ▁of ▁the ▁eight ▁He   1 7 7 ▁V - series ▁pro tot ypes ▁at ▁the ▁request ▁of ▁the ▁R LM , ▁and ▁the ▁Luft wa ffe ▁High ▁Command , ▁with ▁the ▁concerned ▁government ▁ag encies ▁cit ing ▁the ▁desire ▁for ▁a ▁d ive - b omb ing ▁cap ability ▁to ▁be ▁present ▁even ▁with ▁a ▁heavy - b om ber - s ized ▁off ensive ▁war plane , ▁something ▁Ernst ▁He inkel ▁veh ement ly ▁disag re ed ▁with . ▁ ▁By ▁April ▁ 1 9 3 9 , ▁interest ▁in ▁developing ▁a ▁high - alt itude ▁version ▁of ▁the ▁He ▁ 1 7 7 ▁had ▁ar isen , ▁and ▁on ▁April ▁ 2 7 , ▁ 1 9 3 9 , ▁the