HC,
Mssrs Sod and Murphy can sometimes conspire to thwart the best calculations and assumptions and when that happens the best Statistical Analysis will not provide the least bit of cushion of a sudden meeting between Metal and the Earth.
As "meticulous" as Pan Am's first Chief Pilot was, Those two Gentleman ganged up on him.
http://www.clipperflyingboats.com/pa...s/edwin-musick