4Greens............
Hang onto your copy - it is a collector's item
Indeed it is! I got a copy of it a few years ago......................it's 'gold'!
Another collector's item is the old Boeing Jet Aircraft Performance manual
if you can get a copy of it. It's got some really good explanations about how to work out some of the more difficult performance problems. But it's not as 'elegant' as Wal's text was!
It's really unfortunate that there were unfinished sections in Wal's excellent publication.
