Alan, I've took a look at that document.....
It does have some good stuff, but like all documents/information it's a case of sifting through it to determine what's correct and what's not.... and that's not me just being picky about what data I wish to use or not..
For instance, there's a cut away graphic which shows the pressure and gravity tank behind the pilots chair... this clears up this for me.
There's also a statement as to the weight of the guns and I think he's got this wrong, having not removed the water weight but taken a standard ground forces weight.
Also which is the hardest to accept is the lift to drag values coming out of his model testing... they're not exactly a confidence builder that the rest of the values are correct.
Simon