Originally Posted by
ERJ Jay
The Howgozit only "works" if:
You don't change ANYTHING.
Fly faster to make A:00 - will be off.
Fly .80 in a 764 instead of the ridiculously slow .765 that SABRE filed you at - it will be off.
Intentionally fly slower to make a curfew landing time in LHR - it will be off.
Fly different altitude for smoother ride - will be off.
Get a track change - will be off.
The howgozit does NOT update anything that you've changed from the SABRE flight plan.
So, it's a "ballpark" comparison of what you're doing vs what you were planned to do.
Do I ever look at it once I print it - no.
In fact I ask if guys even want it printed - some say yes, most say don't bother.
But I do leave the progress page up on the FMC to make sure the fuel stays close to what it said when we took off.
Well your first issue is that Sabre is planning you at .765 and you're flying at .80 for ATC, crossing, home leg, just feel like it, so of course it's going to be off. The Sabre flight plan has some data to tell you roughly how much so at least you can take a wag at how much more gas you're going to burn.
But the Howgozit is not then rendered worthless. Pull up another one several fixes down line and you will see that it has recalculated your landing fuel and time based on what you've actually been flying. Better still, contact dispatch and tell them you're flying .80 and a different flight attitude and have them re-run your FP. Then pull up a new Howgozit and it will give you the accurate numbers.
Not sure why the disdain for it. It's a good tool for the tool chest and eliminates the multiple math errors I saw guys making before it existed