Are these major operators reporting any savings from flying flex tracks vs fixed route structures?
Missy,
A couple of things to say about that: By various names, flex track long predates ADS-B, in particular in oceanic areas, where there is no ADS-B, and isn't going to be, any time soon.
Over Australia, RVSM did produce very obvious savings, the domestic route network is close to optimum tracks anyway, direct tracking under TAAAATS produced a bit more flexibility, much of the claims for ADS-B never were realistic, more your standard snakeoil salesman.
The two CASA alleged "cost/benefit" studies were proof of that! The first showed big benefits for airlines, so GA was just going to have to lump it.
Then the missing decimal point was "pointed out", and the airline benefits evaporated, to be replace by all sorts of mythical benefits for GA in the second --- but none of which accrued to those who had to spend the money --- and all of said benefits required widespread low level coverage --- the satellite links from the ground stations, alone, would have needed at least one new bird in space, probably two. Please don't quote me, but the "GA benefits" would have needed about 390+ ground stations --- $$$$$.
The reduced separation standard with ADS-B is obviously fact, turning that into measurable savings is another matter entirely.
At least FAA don't make a lot of spurious claims for ADS-B, it will be interesting to see how close to the wire it will go, before shifting said FAA mandate years into the future ---- because that is what will happen, because the alternative is going to be grounding a large percentage of the US airline fleet, and that will not happen.
GA is way ahead of airlines in US, in fitting ADS-B, but that is going to degenerate into a shambles, no doubt.
Here, airlines just roll over to bureaucratic impositions, and the customers pay. Sadly, GA is fading away.
Tootle pip!!