It will be understood that {HEAD ~ member 50 v} refers to those cross members that are connected vertically between vertically adjacent spar members 40 and cross members designated 50 d refer to those cross members that intersect and diagonally join {TAIL ~ two adjacent cross members} 50 v 
It will be understood that { HEAD ~ member 50 v } refers to those cross members that are connected vertically between vertically adjacent spar members 40 and cross members designated 50 d refer to those cross members that intersect and diagonally join { TAIL ~ two adjacent cross members } 50 v
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH