The following steps show how you can use the ETOW fields to complete a comparison burn.
This new feature allows you to see the effect of adding last minute weight to the aircraft before departure, by computing up to two comparison burns.
Select Use Primary in the Secondary Route Use primary list item.
Selecting Use Primary uses the original route selected under the route button.
Here we will see how adding 6000lbs of weight to the original ETOW will affect the fuel burn without changing the route or flight level.
Enter 6000 into the ETOW +/- field.
Select Use Primary in the Tertiary Route list.
Here we will see how removing 6000lbs of weight to the original ETOW will affect fuel burn without changing the route or flight level.
Enter -6000 into the ETOW +/- field.
Once you compute a flight plan, you can see the difference in burns with the different weights.