These were taken at one of the Greater Des Moines Aviation Expos.
This is the B-29 that I first saw fly at the Byron air show that was held
at Ida Grove, Iowa before they moved it to Des Moines.

The B-29 is 1/5 scale
From the notes on the photo the wing span is just under 29 feet.
The aircraft weight is about 400 lbs.
There are 4 Quadra 100's to power the plane.