Captain Pit Bull
It's equivalent in being (1) a force that is (2) equal and (3) opposite to the drag, thereby (4) keeping the aircraft at a constant speed. But is not actually thrust in terms of being a powerplant squirting air around.
Agreed. However, relative to the airframe, there is no difference in drag v. Thrust, simply because no energy is being consumed in the form of fuel. With the standard four forces model, cruise flight is balanced among four assumed forces. When one of the required forces is diminished (or enhanced),
a change in E occurs. To slow, Thrust is removed, and the other three are left to establish some form of attitude that will result in arrival.
Simplistically, which of the two aircraft under discussion can remain aloft the longest, the heavier? The lighter? Because that introduces Galileo, no?
Thanks for your response, lyman