Has any human powered aircraft ever left ground effect? Given their enormous spans I’d think ground effect already is the solution and always has been.Could ground effect be the solution...it is still flying isn't it ?
I’d be curious if the last two Kremer prizes (which I believe are centred around speed) could be won with some sort of hybrid electric rig. For example the first half hour of the marathon would just be pedalling in place to charge a battery or other energy storage device, then release the brake and fly 52mph on the stored energy plus pedals for the last half hour. In my head there ought to be slightly less energy available due to transmission losses but perhaps that could be countered by not having to have an airframe to meet the needs of so little sustained power as we’ve seen to date.