The distribution of parametric weight estimates into detail structural component (target) weights is a difficult and time consuming process. Traditional methods use a high percentage of historical data and are not very responsive to advanced structural concepts. More accurate procedures are needed to establish better credibility as well as identify potential overweight areas earlier in an aircraft program. Use of the Finite Element Model (FEM) in distributing structural target weights was applied for the first time at McDonnell Aircraft (MCAIR) on the A-12 Project. The FEM contained the level of detail necessary to establish major structure target weights for the unique aircraft design and also provided traceability back to the strength analyses. Weight factors were derived to adjust the baseline stiffness model to represent detailed target weights. Additionally, the FEM was used as a check on the structural subsection weight distribution between MCAIR and its A-12 partner General Dynamics. The methodology developed has benefited related R&D projects and other aircraft programs (including the F/A-18E/F) which are using the FEM as a weight estimation and control tool. NOTE: Due to the sensitive nature of information related to the A-12 program, this paper has omitted data considered classified or which may give a competitive edge to any of the teams involved in the AX program.