560 miles by Beverly E. Howard Jr. in an SHK from San Marcos, Tx to Wichita, KS on July 9, 1974

That was a very long day ;-)

The hell of it was that I ran off my charts in Oaklahoma, so, at the end of the flight I was completely focused on locating airports. Since I assumed that there was no chance of making Wichita that when I had that airport "made" I went ahead and landed... from almost 8,000 feet... had I been thinking rationally, I might have made the better part of another 100 miles.

Would not have made any difference though... the SSA rejected the flight documentation, so, I didn't even (or ever) get diamond distance... think I still have the barograph trace around here somewhere.

Beverly Howard