Maybe I am wrong (I am always open to debate) but...
I went through the documents;
http://www.faa.gov/other_visit/aviat.../SAFO12007.pdf
and
https://fdx.alpa.org/LinkClick.aspx?...%3D&tabid=4536
Regarding the FAA rules, you are right, Table 1 is showing the wake standards at the Threshold.
But I'm not sure about the statement:
IF the runway has a 2.5nm MRS, then the min wake is 2.5nm, IF the runway has a 3nm MRS, then the min wake is 3nm. I just went through this at KMEM and FedEx.
I mean, if the airport is not allowed to use 2.5nm spacing, it does not mean that the wake turbulence separation (minima) changes... As far as I understand, the 2.5nm is always the very minimum wake (FAA), but to be "unambiguous" regarding the minimum separation in sequence for different airports, the MRS is stated. (And MRS is never below 2.5nm, so never less than minimum wake sep.)
You can also go through;
http://www.wakenet.eu/fileadmin/user...T_FAA_Lang.pdf
and you will find some blank cells in ICAO tables...
Anyway, the first impression when reading the presentations is, that wake sep. are still "overly conservative".
