AOTW, sunk costs are irrelevant in accounting terms. There is no logical or economic argument for "finishing the project", as others have pointed out this has been going on for Twenty years at great expense and much pain and suffering.
What to do? Throw it out. Throw out the management that attempted the project in the first place and throw out the lawyers because the people who got us into this mess by definition are not the people to get us out of it since they will automatically pervert any new project.
Buy a copy of the New Zealand Regulations and start from there as a "greenfield" project.
P.S. Please stop with the "sweet reason" arguments implying that CASA people are honest and good with our best intentions in mind.
The reality, judging by the experiences catalogued in the Forsyth review and ad nauseam in Pprune as that they are lowlife, vindictive, scum. Don't you remember the conclusion of the Forsyth report? That CASA has lost the trust of the industry?
If draconian penalties are available to CASA then the current mob will use them to the hilt to cause as much pain and suffering as possible.
To put that another way: There is a long catalogue of deliberate dishonesty, vendettas, persecution, deception, capriciousness, inequity, inefficiency, unfairness and injustice by CASA….and you want to give them more power and reduce what little defences we have against these bastards even further???????????