This is a Significant Other milestone.
Harold Pitcairn of the Autogiro Company of America (ACA) sued the US Government who he felt had infringed on patents owned by ACA in the design and manufacture of many early US helicopters for the US military. It became the longest patent infringement lawsuit in US history, finally ending in October 1977.
Source: "Autogiro Company of America vs. the United States No. 50328, 181 Ct. Cl., 384 F.2. 391 (1967) - How the Longest Patent Case in U.S. History Defined the Rotary-Wing Legacy of Harold F. Pitcairn", Bisanz, M., Paper presented at the 63rd Annual Forum of the AHS, Virginia Beach VA, May 2007)