[0]  => Airline_1
[1]  => Second Air
[2]  => Авиатор
[3]  => Аврора

uasort($newCompanyList, function ($a, $b) {
        $at = iconv('UTF-8', 'ASCII//TRANSLIT', $a);
        $bt = iconv('UTF-8', 'ASCII//TRANSLIT', $b);
        return strcmp($at, $bt);
    });

[0]  => Airline_1
[2]  => Авиатор
[3]  => Аврора
[1]  => Second Air