There are many pants these days with a touch of elastene in them. Any of those that fit you work great. I found a jeans brand (William rast) and bought about 5 pairs in different colors (black, raw and blue) and they are my go to travel pants. Pretty much any decent brand will have a model with elastene...

some of my colleagues love their LuLuLemon pants.

Source: 50–60 flights a year mostly international