Those procedures had been in place at LHR since well before my time (don’t forget, we used to have LHR-specific separations too (off the top of my head, H-L was 7nm, not 8nm as in rest of UK) and were proven to be safe. LHR did not have any greater rate of wake encounter than anywhere else, as far as I know.
If you take the RECAT EU threshold separations, and add on the compression, it’s striking how similar those distances are to our previous 4DME separation distances.
Introducing RECAT and TBS v2 was a long term goal agreed by UK CAA and NATS to move to separation to threshold.
I prefer to think of it as LHR was running a long term trial of RECAT EU threshold separations.
