I was in one of those back in the '80s jumping out of a Loadstar in Florida. About half of the load got out, me included and the rest went down with the plane to about 6,000 before he got in out of the spin. A couple of years later, the same thing happened with a similar plane in Washington but the whole load went in with the plane. That was the end of jumping from those planes. Never saw it with DC3/C47 but with 40 jumpers all way in the back and the airspeed too low, that's the result.