washington u.s. senate arm service committee chairman john mccain thursday vow block use cost-plus type contract government would responsible cost overrun new long-range bomber build northrop grumman corp. mccain tell reporters would seek block authorization new u.s. air force long-range strike bomber current form argue cost-plus deal inevitably lead cost overrun disapprove ... authorize program cost-plus contract mccain say ask contract u.s. air force already sign northrop mccain say military often argue cost-plus contract necessary case involve cutting-edge technologies since unknown problems could emerge practice unheard silicon valley air force say engineer development phase program value 21.4 billion structure cost-plus contract incentive fee second part contract would cover initial production first five set new bombers usually expensive plan new class aircraft would structure firm fixed-price air force disclose full project cost program although say expect pay 511 million per plane 2010 dollars air force value oversight role senator mccain look forward continue work committee move forward critical capability department nation department look forward able provide senator complete brief program early convenience aerial warfare service say officials expect brief mccain next couple weeks spokeswoman say northrop decline comment senate arm service committee counterpart house representatives approve legislation set defense policy fund military govern house senate appropriations committees mccain also take issue high level secrecy shroud bomber program air force refusal thus far divulge name key suppliers program someone want build engine airplane require congressional authorization must know make circumstances say committee chair mccain vow block contract new northrop bomber