Ear‐to‐ground

HOT UNDER THE COLLAR is the title of a technical note in the most recent issue of the ‘Boeing Maga7inc’. It describes how NASA engineers initiated a study to eliminate heavy steel flanges which were being used to join mechanically certain sections of fuel lines located in rocket fuel tanks. The flanges fasten 20 in. diameter aluminium fuel lines to flexible stainless steel bellows, the latter being necessary to absorb shock and vibration during liftoff. The mechanical fastener method was adopted because steel and aluminium could not be welded together satisfactorily.