Ryanair Group (RYAAY) Chief Executive Michael O’Leary on Tuesday said that Boeing’s (BA) new management “continue to disappoint” and that deliveries were behind schedule.

The Irish airline, one of Boeing’s largest customers, said there was a risk it would take delivery of just 20-25 of the 737 MAX aircraft ahead of next summer, rather than the 29 scheduled.

“Things are continuing to slip slightly, it’s been disappointing,” O’Leary said.

“We’re working closely with Stephanie Pope and the new team in Boeing, but they continue to disappoint us,” he said, referring to the head of Boeing Commercial Airplanes, who was appointed in March.

Boeing last month named aerospace industry veteran Kelly Ortberg as its chief executive.

Boeing has pledged to grow output by the end of the year, after wrestling with supply chain snags and operating a slower assembly line since a Jan. 5 in-flight blowout of a door plug on a 737 MAX 9 jet that heightened regulatory scrutiny.

O’Leary said Ryanair had received five aircraft in July instead of the seven scheduled and that it looked like it would get just five of 10 scheduled for August.

“Boeing have had significant production problems. We think they’re getting to the end of that,” he said.

Ryanair said in July that Boeing had warned it some 737 MAX deliveries due by next spring would be delayed until the peak summer months of 2025 – a repeat of delays this year that forced a cut in its summer traffic volumes.

Ryanair, Europe’s largest by passenger numbers, already has 150 firm orders for the MAX 10, the largest jet in the 737 family, and options for 150 more, with the first deliveries due in 2027.

O’Leary said the smaller MAX 7 was supposed to be certified by the end of this year, but that looks like slipping into the first half of 2025.

He said it was “impossible to know” if certification of the MAX 10 would be on time in the first half of 2025. “It’s a day-by-day challenge with Boeing.”