A320 MCDU : Fuel Pred ...help needed
 

guys i need help regaring the Fuel Pred page in the MCDU of an Airbus A320
the page says
at [5L] it says FINAL/TIME
which says that the pilot can modify this field,and it is the fuel you need overhead the Final destination.and holding at 1500 greendot speed
suppose you need 0045 mins of holding over ur destination does that mean that you simply punch in /0045 and punch in th 5L line select key.and the comp will tell you the fuel.


and at [6L] EXTRA/TIME
it says that the same description as for FINAL/Time whats the difference between the two.
can any one please bother to clear my doubt.
it would be very helpfull to me.

:ok::ok::ok:

1. Yes punch in 0045.

2. EXTRA = BLOCK - (TAXI+TRIP+RSV+ALTN+FINAL)
FCOM 4.03.28

who says FINAL & EXTRA is the same description ?

thank you very much
Appreciate your response
:D:D:D:D:D

My understanding is that this is 30 minutes worth at 1500 agl, and is the fuel you must have left in the tanks after touchdown.

In my company, as soon as you realise that you may go below this figure, and still be airborne, you have to declare a MAYDAY. It is of course landing weight related.

Any fuel you want to use for anticipated holding should be in the EXTRA field.

Bear in mind you should be able to use the contingency fuel for holding if your burn to the holding point (taxi, climb cruise and descent) is as predicted by the operational flight plan.

Also, depending on company rules, you should be able to anticipate binning your diversion fuel if you meet all the requirements. But Final reserve is just that.

You can insert the required time for final reserve: either 30 min (europe) or 45 min (USA?). Or you can insert the final quantity, if you like.

Then, according to that, and to fuel on board and EFOB, the FMGC gives you the estimated extra fuel at destination and extra time.

What I tend to do is look at what the FMGC is telling me what it think it will burn going to the alternate, then look at what the difference is on the flight plan since that takes into consideration the go-around and flight plan route to the alternate. I then put the difference into the route reserve instead of it having the 5% contingency. In the extra fuel section that will then show you the extra fuel you have including your contingency fuel.

I always round up and never down. When I do fuel check how much extra fuel the flight plan tells me is the same as the extra fuel the FMGC is also telling me.

that's a good way of having a meaningful extra fuel number.

What I do is insert the full alternate route with SID and STAR, if any, and check if the alternate fuel figure is the same as in the computer flight plan. If it is reasonably similar, then I do nothing else. If cfp alternate fuel is signigicantly greater then I just keep that in mind and mention it in the briefing.

Check the box's default alts vs your flight planned levels too!