Seagull,
Good information....
Within the RNP procedure designs, there have been some issues with the winglets/sharklets. They tend to be a bit more slippery, so especially when there is a turn to short final, which is usually a smaller radius turn, the criteria design just wont work, the ac will roll out of the turn.
I would also note that Airbus now uses a 2.8 GPA for RNP procedures with their sharklet ac (like all) due to the energy management issues on final...
Given that the criteria for the A320 is usually a Cat C, with FAS of 140 kts, its easy to see how a design turn cannot be realistic for the ac. (if the turn is to FAF, the CAT speed is used for the entire turn..in the criteria)
There have been many procedures that worked very well before the for same ac with/without winglet/sharklet issue, and have now been modified or abandoned.
Interesting note on the crosswind. I will ponder that as the criteria considers wind always as a tailwind, that follows it through the turn. There is no consideration for crosswind...
Last edited by FlightPathOBN; 14th May 2013 at 20:17.