> Yeah, I have been reviewing this, and I think I understand how the definition 
> works. I'm getting pretty much the same numbers based on the 2900 and .35 
> which 
> I got out of the POH and several internet sources on the cyclone engines. I 
> have 
> a more appropriate yasim file now, but I still can't get it to solve, so I 
> wonder if there is another problem somewhere else?  Maybe I have screwed up 
> the 
> aero data and it is producing way too much drag.
> Here's the latest:
> http://home.comcast.net/~jrbabcock/superfort/b29-yasim.2.xml
> Everyone, thanks for all the help so far, it is very appreciated,
> Josh

Not sure if I started with the latest or not,  but this one solves:

This is what I changed:

1) Added fuselage length.
2) Increased wing length to something closer to correct length.  
3) Probably adjusted a couple other less significant numbers that seemed wrong 
(wing sweep angle maybe?).
4) Fixed rpm/power numbers under the prop tags.  They need to be scaled back 
according to the gear ratio.  Someone with a better understanding of mech 
engineering might be able to explain why the BHP on the prop shaft is reduced 
by a factor of 0.35 when that's the gear ratio,  or maybe that is wrong and 
there is something going on in the YASim calcs.  It seems that is what you have 
to do to get a solution that works.  In any case YASim should at least do some 
sanity checking here to avoid the endless loop thing.

Solution results:       Iterations: 1220
 Drag Coefficient: 3.398360
       Lift Ratio: 417.065216
       Cruise AoA: 1.252508
   Tail Incidence: 3.132050
Approach Elevator: 0.268476
               CG: -10.439, 0.000, -0.137

This solution isn't quite right.  I had to knock down your cruise speed and 
altitude, but at least you've got something to go back to while tweaking.  BTW 
I don't know much about the B-29, but did you do that airspeed in KIAS?  365 @ 
25000 sounds a bit high.

Best regards,

Jim Wilson

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