Phoenix_X
9th Aug 2003, 17:43
I'm new to the A320, and after a few attempts at getting a nice descent profile into the FMGC I've given up.
The scenario is the CDA approach into AMS, it's an RNAV approach, which has altitude limits to encourage pilots to fly a 3 degree glidepath minimum from FL70.
On the 737 I flew before, the VNAV would fly this approach perfectly, only reaching the minimum profile at glideslope intercept, and this all the way with idle thrust. This is as the approach was meant to be flown, with little noise.
Now the A320 seems to dive for the first constraint, fly level until passing it, then immediately dive for the next constraint, and fly level, until it finally reaches 2000' in level flight 9 miles from touchdown.
Even worse, if I delete all the altitude constraints, it aims to be 2000' approx 13 miles from touchdown! And then fly level until the glide.
Now for all the 'bus claims about FMGC will help decrease fuel consumption and reduce noise pollution this doesn't seem to fit, and I was wondering wether others have this problem as well. For now, I work out my own profile and fly it with idle thrust and it works out fine. But I'll be up to 3000' above the FMGC profile at times, sometimes more.
Thanks for anyone who can explain!
The scenario is the CDA approach into AMS, it's an RNAV approach, which has altitude limits to encourage pilots to fly a 3 degree glidepath minimum from FL70.
On the 737 I flew before, the VNAV would fly this approach perfectly, only reaching the minimum profile at glideslope intercept, and this all the way with idle thrust. This is as the approach was meant to be flown, with little noise.
Now the A320 seems to dive for the first constraint, fly level until passing it, then immediately dive for the next constraint, and fly level, until it finally reaches 2000' in level flight 9 miles from touchdown.
Even worse, if I delete all the altitude constraints, it aims to be 2000' approx 13 miles from touchdown! And then fly level until the glide.
Now for all the 'bus claims about FMGC will help decrease fuel consumption and reduce noise pollution this doesn't seem to fit, and I was wondering wether others have this problem as well. For now, I work out my own profile and fly it with idle thrust and it works out fine. But I'll be up to 3000' above the FMGC profile at times, sometimes more.
Thanks for anyone who can explain!