Originally Posted by
DirtyProp
Eight jet engines flying pretty much MSL all the time.
I wonder what the theoretical fuel burn might be....
In principle pretty low - the point of WIGEs is that once airborne they operate in a very low-drag regime. Based on the data from the original one I'd guess that the eight engines are only used for take-off; cruising flight will probably use only four or even just two.
Of course this does mean that the take-off run can be a bit "leisurely", but then flying boats always did exploit the option of using very long "runways" and shallow climbs. Who cares if it takes 20,000m to leave the water and only climbs at 50ft/min? It will reach top-of-the-climb at 200 feet anyway, so there's no real "noise abatement" benefit to steeper climbs.
No, the *actual* disadvantages are that they can only operate over large areas of water, so the would be as much use as a chocolate fireguard for arctic/ant-arctic rescue. They also can't run over rough seas - even if anyone wanted to they don't have the control authority to safely fly at 200 feet through a deep ocean storm, and the WIGE principle is a bit dodgy if there's a deep swell running.
IMHO the whole WIGE thing is still very much a solution desperately seeking a problem.
PDR