News for hackers. Stuff that matters.

A comment on Drop the Supersonic Aircraft Ban. Parent comment

Re:Drop the Supersonic Aircraft Ban by Gravityloss on Monday June 13, 2016 @03:38PM (#11896759)
As lift is also proportional to density, area and square of velocity, that whole term cancels out from the equation of fuel usage per distance, basically only L/D or cL/cD matters.

In practice it might be a bit more complicated.

EDIT: indeed here we can see that Concorde had lift to drag ratio of only 7.5 at Mach 2, while Boeing 747 has 17.7 at Mach 0.9 or so. https://en.wikipedia.org/wiki/Lift-to-drag_ratio

[ Parent | on HN ]
Re:Drop the Supersonic Aircraft Ban by DrScump on Monday June 13, 2016 @04:38PM (#11897413)
But you should also factor in their comparative passenger capacities (e.g. impact per passenger-mile).
[ Parent | on HN ]
Re:Drop the Supersonic Aircraft Ban by Gravityloss on Monday June 13, 2016 @06:06PM (#11898113)
Perhaps better would be aircraft weight to number of passengers ratio. Revenue wise the supersonic airliner flies faster, meaning you get more seat miles per day per seat.
[ Parent | on HN ]