Hi Burr,

> I always vote for Value inputs. Sometimes if you know a value,
> its easier if you can type it in.

Yup, in general that's certainly true! But in this particular case you are not very likely to know this special "rho" value beforehand unless you are looking over airfoil tables from the 1960's or something like that... ;)

But I've added it in anyway though.

- Michael