Talk:It's a Bird, It's a Plane/@comment-141.193.16.151-20190930194028/@comment-141.193.16.151-20191008140909

If you want to figure out the flight time that you could get out of the jet pack, you can use the following equation:

ln[1 + Wf/(Wj + Wp)]/tf = Constant

Where: Wf = Weight of the fuel Wj = Weight of the jet pack (empty) Wp = Weight of the pilot tf = Flight time

You have to make assumptions about the jet pack's specifications, then you make a comparison between that and a pilot of a different weight. It may surprise you how much every pound counts.

This equation is based on the assumption that the fuel consumption rate of the jet pack is directly proportional to the thrust that it generates. This is the same assumption made for the Tsiolkovsky rocket equation which has been used for about a century.