The world’s largest airline is experiencing some turbulence.

Yesterday, more than two dozen black pilots and supervisors sued their employer, United Continental Holdings Inc., claiming the company favors white employees over minorities when it comes to promotions.

The suit claims United’s “highly subjective decision making” about promotions leaves minority captains with part-time, nonmanagement positions, whereas white employees receive full-time, higher-wage positions. Additionally, the plaintiffs claim that the few blacks who are in management positions are excluded from informal group emails and social gatherings.

The pilots seek an end to United’s discriminatory practices, back pay and unspecified punitive damages.

The airline said in a statement that it doesn’t tolerate harassment or discrimination, and that it plans to vigorously defend itself against the claims.

Read Bloomberg and CNBC for more about the racial discrimination suit.