Re: Helios never made it to 100,000 ft altitude.
Your right it only flew to 96,863 feet last August.
If you calculate in Mars' lower gravity, Earth altitude which equals Mars' near surface flight zone would be about 86,000 feet.
BTW, I'm not trying to critic the Mars Entomopter's worth, only that you're wrong about fixed wind and rotory wing flight at Mars. BTW, balloon's work fine as well. The NWS and NOAA regularly launch hydrogen balloons to about 100,000 twice a day, everyday of the week.
Nothing stops a mission design having a rover making a landing strip if need, but most Mars aircraft mission designs drop the craft and it eventually crashes.
--Chris Vancil