Revenue during the quarter went up marginally by 2.75 percent to $8,420 million from $8,195 million in the previous year period. Gross margin for the quarter contracted 416 basis points over the previous year period to 61.13 percent. Total expenses were 96.70 percent of quarterly revenues, up from 92.08 percent for the same period last year. That has resulted in a contraction of 462 basis points in operating margin to 3.30 percent.

Operating income for the quarter was $278 million, compared with $649 million in the previous year period.

However, the adjusted operating income for the quarter stood at $329 million compared to $839 million in the prior year period. At the same time, adjusted operating margin contracted 633 basis points in the quarter to 3.91 percent from 10.24 percent in the last year period.

Oscar Munoz, chief executive officer of United Airlines, said, "In the first quarter of 2017 our financial and operational performance gives us a lot of confidence about the foundation we are building. It is obvious from recent experiences that we need to do a much better job serving our customers. The incident that took place aboard Flight 3411 has been a humbling experience and I take full responsibility. This will prove to be a watershed moment for our company and we are more determined than ever to put our customers at the center of everything we do. We are dedicated to setting the standard for customer service among U.S. airlines, as we elevate the experience our customers have with us from booking to baggage claim."