in hero factory, there is the drop-ship, they made a set, but not very accurate, anyone got an idea, or ideas on how to make a drop ship, though completely covered, insulation maybe, and the back hatch with ramp could actually hold three to four hero's and the cockpit of course holds one to two

I'd say the Drop Ship in Hero Factory is pretty good in terms of set design. The issue with designing a larger and more well-covered one is that you want it to be something you can properly swoosh around. These days, hero sets are even larger than they were in 2010, so making a vehicle to contain several heroes would be quite an ordeal. Best case scenario, you fit three in the main cockpit like in some episodes of the TV series. But even that would be starting to get awkwardly large to fly around.

Overall, I'm not a competent enough Technic builder to really do something of this sort, but I'm sure the first step to making a larger drop ship would be to get lots and lots of Technic panels (of the newer variety that's been appearing in sets since around 2008). That'd give you a nice, sturdy, and mostly solid outer shell to work with. Beyond that, you're on your own.