Posted for Walter Atkinson <walter@advancedpilot.com>:

 Rick:
 
 I think there may be one error in your assumptions about the turbo at  low
MPs during descent.  I could be wrong, but the compression ratio of  the
turbine is always a set value.  At low MPs, you just have less of  that raised
temp air.  The heat rise from the compression of the gas  should remain pretty
constant.  What am I missing?
 
 (I'm anxiously awaiting the response from Craig to your 10 long  questions!
<g>)
 
 Walter