On the Beach,
I completely agree with you. While RNP has been sold down the drain with the benefits of fuel savings on idle descent, the reality is that I cannot see how this works, and have been marginally successful in some of the coding tricks mentioned above. Unfortunately, now the funding is all towards a solution that does not work.
When I first got involved with RNP, and the mantra idle descent, (to somehow fund the cost), I struggled with the concept, first off, asking if anyone had talked with ATC about all of this.(which of course I found out NOT)
So in trying to balance this, there are still certain variables to work with...
For me, Econ cruise means the ability to meet the timing, without demurring or a go around...if you have to knock off 5 kts enroute, to drive in, then that is econ cruise...
What is econ for one ac is not for another....
You have a slot, you make that slot, TOD off the enroute can still be idle descent to the hard point at the outer marker. The computer can calc this out, just back out the time needed to be at that waypoint.
We can work this automatically through the intent bus, and ADSB already.
I hate when I get feedback like you are saying, and it is really difficult, on CDA, with idles descent, when you have a 747 F, and an A320 following..
As far as turbulence, if you have coded routes, that can easily solve that issue. Whn you get in close, have the heavies on a 2.8GPA and the mediums on a 3.1GPA...everyone will be fat and happy. That all fits within existing ILS GPA and the lighting...
As you guys are aware, wake turbulence is being looked at with real time systems. When that all gets sorted out, the first thing you will see is a change in SOP for approach. Then you will see Boeing and Airbus getting serious about their wing designs, which currently, date from when?
The flex wings on A350 and 787 may have some potential, but if the current computational fluid dynamic models are still in use, don't expect too much from that. Just look at all of the recent 'new' winglet configurations that all are 5-7 percent more efficient than the last or the 'other' manufacturer...
Stepping back, the wake sep is one of the biggest constraints in the mix for ATC...look for a radical change in the next few years...
Last edited by FlightPathOBN; 5th Jul 2012 at 22:11.