I was thinking about it. if you build a small plane but find that it woun't fly try this. Put helium in the wing cavity. you have to make sure that it is airtight, with the exception of two rubber pump holes, on oppasite sides. Like the type of a basketball. tilt the plane on its side. tkae the helium pump and pump the heluim in to the top hole. meanwhill but a holow pin on the bottom hole to let air out. you need to find a heluim pump somewhere. not sure where but i have seen them. I you make it airtight the helium shoudl stay in for a while.

And ideas on this?

Alex

P.S. desighing my elevation conrtol will be here soon