Originally Posted by
caveruner17
On a serious note, why does it matter?as long as maint. is kept up, they are safe
This.
If an airframe is properly maintained, the age of the design doesn't much matter when it comes to safety. [Thus, on your list, I personally would feel uncomfortable flying Iran Air b/c of maintenance concerns -- because of sanctions they have difficulty getting spare parts]. The issue with age of the design is that because of advances in materials and engines, older designs are inefficient.