Lonewolf 50:
In your comparison of either/or, and I think you have a detailed understanding of this, why won't the FAA budge on the 2.3 nm? Why not 3sm or 3nm? There is probably a reason, but I don't know what it is.
FAA and U.S. air carrier politics. ALPA and others started working for better CTL criteria for TERPs perhaps 15 years ago.
The 767 CTL crash in Korea got the technical folks at the FAA off the dime. When Change 21 to TERPs was issued about a year ago, it contained vastly improved CTL criteria--sort of the fit BOAC would like.
But, a fairly high level FAA manager placed a "stop" on the new CTL criteria even though the signatories and industry had signed off on it and it became "law" (FAR Part 97) so to speak.