I have just finished reading the linked item below.
http://www.faa.gov/about/plans_repor...port_final.pdf
As suspected, the usual observations are there. Lack of ownership of requirements, inadequate v&v coverage and use of previous design experience without re-validating the design assumptions.
Nothing new, and that is what concerns me. Not disasterous as an individual item, no outright condemnations, but as the report shows that the GCUs were a deep-dive item, the process seems to be struggling with managing the complexity and nature of these next generation projects. In this case the inevitable system level impact of a low-level design decision was not spotted, perhaps due to the amount of responsibility boundaries that had to be crossed between.