Questions about A330/A340 operations

[mozart 1]

I have a couple of questions re: the A330/340, which the manual couldn't clearly explain to me:1. Approach modeI understand that approach mode engages automatically when overflying the deceleration point before landing. However, what happens when ATC vectors me in in a way that I don't exactly overfly that decelaration point? WIll approach mode still engage at a point somewhere near the planned deceleration point or do I need to do it manually?2. Descent path indicatorIt's a handy little thing, but I am not 100% sure what it can do and what not:- suppose during a descent I exactly follow that indicator, would that bring me down to runway altitude at the threshold? Is this indicator a 3 degree glideslope?- is it possible to lock the autopilot to that descent indicator, so that the autopilot follows that profile?3. Expedite climb/descentI just didn't understand what the manual says. What's the difference between this mode and, say, OP CLB or OP DSC? Or between this mode and managed vertical mode? ALso, I don't seem to have that EXPED button on my A330 panel, it's supposed to be underneath the ALT selection knob, right?4. Finally, cabin altitude: I've head the case where I was flying on FL370, and when the FMCU told me that the optimal altitude was FL392, I climbed to FL390. But there suddenly the cabin altitude was too high? Why? How can I avoid that from happening? And when it happens, how can I fix it?Thanks for any hintsChris

[Guest bjornhall]

Hello Chris,I might be able to answer a couple of those...>>1. Approach mode>I understand that approach mode engages automatically when>overflying the deceleration point before landing. However,>what happens when ATC vectors me in in a way that I don't>exactly overfly that decelaration point? WIll approach mode>still engage at a point somewhere near the planned>deceleration point or do I need to do it manually?Wouldn't know, since I always engage it manually when I see fit (typically around 15 track miles from touch down, but earlier if there's a need for tight maneuvering).>>2. Descent path indicator>It's a handy little thing, but I am not 100% sure what it can>do and what not:>- suppose during a descent I exactly follow that indicator,>would that bring me down to runway altitude at the threshold?>Is this indicator a 3 degree glideslope?>- is it possible to lock the autopilot to that descent>indicator, so that the autopilot follows that profile?>It guides you along the calculated descent path, which depends on how you set up the FMGC (F-PLN page) for landing. If you have the GS intercept point inserted, with an altitude restriction at that point, it will guide you to be at the proper glideslope interception altitude at that point. It will not guide you to the runway, normally (but you could probably set it up to do that if you insist; it's not standard procedure though, since the non-precision approach mode of the autoflight system isn't implemented).If you are in managed DSC mode, the autopilot will capture and follow that profile.>3. Expedite climb/descent>I just didn't understand what the manual says. What's the>difference between this mode and, say, OP CLB or OP DSC? Or>between this mode and managed vertical mode? ALso, I don't>seem to have that EXPED button on my A330 panel, it's supposed>to be underneath the ALT selection knob, right?>EXPED is essentially a quick way of resetting managed speed to a speed giving the maximum rate of climb or descent. You can use it in OP CLB, OP DSC, CLB and DSC. You could as well go to selected speed, setting speed for maximum climb rate in climb or Vmax in descent.There is no such mode in the A330 and A340 as per the real life manuals; however, that might be a carrier option.>4. Finally, cabin altitude: I've head the case where I was>flying on FL370, and when the FMCU told me that the optimal>altitude was FL392, I climbed to FL390. But there suddenly the>cabin altitude was too high? Why? How can I avoid that from>happening? And when it happens, how can I fix it?>I think there is something fishy with the pressurization systems as implemented in the PSS buses... The workaround is to control pressurization manually when climbing above FL370. That is simpler than it might sound in this particular scenario: Just push the MAN button passing FL370 on climb, leaving the cabin VS at 0, then push it back to Auto when passing FL370 on descent.As an aside, manual cabin altitude control is a tad more complicated when flying in and out of La Paz, Bolivia, something I did the other day... It's fun though! :)>Thanks for any hints>Hope this helps!Best, - Bj

[mozart 1]

Thanks a lot Bj