digital engine control. Other diagrams show stub wings each with two weapons pylons. ... supersonic ramjet, or aquot;scramjctaquot;, which would probably operate for 1, 000 to 3, 000 seconds, using liquid hydrogen as, aamp;.constituent. ... These guidance sub-systems would be progressively tested during 1990, as a preliminary to operational deployment by 1993. ... General Dynamics is gearing up this week to send ten engineers to Mitsubishi Heavy Industries (MHI) headquarters in Nagoya, Japan, anbsp;...