Hi all
I've noticed that when I attempt to program the CDU/FMC especially at high weights - 240K upwards the system will not accept it and I can only input lower weights -235K for example. Since I am unable to program the weight carried in cargo lower chart the remainder of the automated calculations are made using that lower weight probably there affecting things like V-speeds.
Am I missing something in weight management of the 757 that I need to recognize in order to end up with a correct set of values for the airplane?
Thanks
Warren

aspen31 wrote on Apr 18^th, 2021 at 10:36am:

Hi all I've noticed that when I attempt to program the CDU/FMC especially at high weights - 240K upwards the system will not accept it and I can only input lower weights -235K for example. Since I am unable to program the weight carried in cargo lower chart the remainder of the automated calculations are made using that lower weight probably there affecting things like V-speeds. Am I missing something in weight management of the 757 that I need to recognize in order to end up with a correct set of values for the airplane? Thanks Warren

Where are you putting this? ZFW? Gross Weight? The Weight manager?

Hi
"Initial Reference", top left corner, "gross weight" doesn't happen all the time - seems more likely at the higher aircraft weights.
Warren

aspen31 wrote on Apr 18^th, 2021 at 3:11pm:

Hi "Initial Reference", top left corner, "gross weight" doesn't happen all the time - seems more likely at the higher aircraft weights. Warren

Usually that's not filled in by pilots. Are you putting in your actual ZFW in LSK 3L? That's usually how it's initialized and gross weight is auto calculated by the airplane. But you're right it should accept all values up to the MTOW. Try loading the plane to a high weight like 254,000lb and putting in the respective ZFW into PERF INIT LSK 3L and see if it accepts that and see if your LSK 1L will now show the high gross weight.

Hi
Ill have to some additional figuring. When I use the figures published for "empty weight" in the "fuel and payload" section under aircraft the cdu calculates and adds a gross weight which is different than the total weight published as total weight on the cargo load page. Is "total weight" on the cargo page that of the cargo or the sum of fuel + cargo + empty weight of the airplane. If not a total where do I find these values given that calculations are made automatically in the CDU once a ZFW or gross weight is input.
Perhaps I need a refresher for calculating these values.
Thanks
Warren

If you right click on either LSK1L (GROSS WT), or LSK3L (ZFW), it should automatically enter the correct weight in both GROSS WT and ZFW.

Thanks
The concept seems to work. I was trying to do everything manually and was having trouble getting the figures to work out. I'll start leaving it to the computer.
Nice machine
Warren