Technical authority is a concept where the engineering management hier- archy is separate from the program management hierarchy. The intent of this organizational structure is to insulate engineering calculations and decisions from financial and schedule influences so engineering quality can be preserved. This paper looks at the technical authority structure and process within the US Navy acquisition and engineering directorates and discusses why this system was established and how it works (and doesn’t) in real programs. The discussion of technical authority focuses on mass properties of a major submarine acquisition program but also includes insight from the other side: the viewpoint of technical authority from the deputy program manager of that program. Together the paper provides insights and examples of why maintain- ing technical authority is important and also how compromises are navigated between good engineering and good program management.