One of the largest purchasers of Boeing aircraft, United Airlines, is growing impatient with the struggling manufacturer.

“I find it disappointing that… at Boeing, this continues to occur. The CEO of United, Scott Kirby, stated in a Tuesday CNBC interview that this is nothing new. “We require Boeing’s success. However, they have been facing these ongoing manufacturing difficulties. This is where they have to act.

Kirby’s remarks came after the airline issued a warning to investors, stating that it would record a higher-than-expected loss in the first three months of this year due to the grounding of all 737 Max 9 aircraft following an Alaska Air flight on January 5 in which a door plug blew off, causing a massive hole in the side of the aircraft.

The Federal Aviation Administration ordered the grounding and extra inspections of the more than 200 jets of that model worldwide, but no significant injuries were reported during the landing.

United Airlines announced that it will report a first quarter loss in the range of $116 million to $262 million and that it now expects its fleet of Boeing Max 9 aircraft to stay grounded through the end of this month. That exceeds the $138 million loss that Refinitiv’s survey of analysts had previously predicted.

According to aviation analytics firm Cirium, United has more Max 9s than any other airline, with 79 scheduled for this month alone. Prior to the incident, the airline had around 8,000 flights booked with the aircraft.

Beyond the immediate 737 Max 9 issue, this also affects Boeing’s orders for the 737 Max 10, a more expensive and larger variant of the 737 Max that has not yet received FAA certification. Kirby stated that United is no longer depending on receiving those Max 10 aircraft in the future because it will take Boeing, in the best case scenario, at least five years to deliver those aircraft to the airline.