Originally Posted by
Smythe
Thanks...it seems odd the cracks (so far) have only been found on the pax version....
Probably just numbers in service, as a fraction of the NG fleet. I don't have all the figures, but the majority of cargo operators seem to be using the B737 Classic (-300 to -500). See:
https://en.wikipedia.org/wiki/List_o..._737_operators