Originally Posted by
FlyingStone
It's discriminating, whether you admit it or not.
Yes it is.
As in: discriminate
/dɪˈskrɪmɪneɪt/
verb
1.
recognize a distinction; differentiate.
"babies can
discriminate between different facial expressions"
2.
make an unjust or prejudicial distinction in the treatment of different categories of people, especially on the grounds of race, sex, or age.
"existing employment policies
discriminate against women"
Language skill-set clearly falls into the "differentiated / distinguish" scope as opposed to the second "be biased / show prejudice".
Unless a very large chunks of the airline itself are based on English language, it might even be borderline illegal to employ a non-native speaking foreigner. Think Security compliance for instance.