Once you get into a little larger birds, a scale becomes almost a requirement. Folks tend to build a little heavier than the 'Pros' do that manufacture the kits. Having said that,there are a number of parachute size/descent calculators available on the net. It's good to have an all up mass for your bird and most should be calculated with the empty casing in place (that what's coming down, right?). So vehicles that are fairly light and can withstand higher impact speeds and some lucky guys can recover on grass or plowed fields. A good rule of thumb is about 15 fps fall speed but YMMV depending on fin arraingements, recovery harness, etc. Start small on the spill hole- you can't add it back in ya know! This reduces the effective lift of the chute but it really serves to ruin the airflow over the canopy which is trying to act like a wing and generate lift over the curved surface as it 'flies' downwind. Straight smoke and good chutes to ya!
Last edited by fyrwrxz; 6th January 2012 at 04:39 PM.
All persons, living or dead, are purely coincidental-Vonnegut
97% of the time, I'm right-the other 5% doesn't bother me.
There comes a point in your life that looks just like all the other points you didn't notice either.
If I had a nickel for every dollar I spent on rockets, I'd have more rockets.
You may have had more fun in your life than me, but the chaos was undeniable.