Wingswinger:
Quote:
"Now, the descent, on the other hand, is a different matter because following the managed path is NOT the most fuel-efficient thing to do.
The reason for the 'bus-struggle in the last 2000 ft to cruise level is usually because you have just found the tropopause and as everyone who has done proper high altitude training as some point in their career will tell you, that is indicated by a drop in engine performance as the air outside is no longer getting colder. The way round it? Select MACH, it will usually be .77 or .78 at this stage, reduce it to .75 or .76 and watch your little 'bus leap up to FL 370 or whatever your desired level is. Don't forget to push managed speed when you go into ALT*."
Now, I would like to know when you did flight testing and data gathering to proove that the calculations and tests made by the Airbus Engineers, Test Pilots and Flight Test Engineers are all wrong for managed descent, please send your data to Airbus Flight Test so they can correct their mistakes.
Also Airbus ST would be very intersted in your new procedure for the last 2000' in climb, I notice it does not make a difference if your cruising altitude will be 310 or 390, just a general statement.
Just let the airplane do the work it is designed to do by people who not only have vast knowledge to do it, but the means to test their findings. If you are so sure about your findings, talk to Airbus, send your sugestions in, they are very receptive, and usually give you a great reason for how they design the systems.
There is a link in one of this posts for getting to grips with fuel economy, read it and understand it, it is very good.
G