- Ryanair's Michael O'Leary criticized Boeing for ongoing delivery delays of 737 Max aircraft.
- Boeing slowed production rates in the wake of January's Alaska Airlines blowout.
- O'Leary also doubted certification timelines for Boeing's 737 Max 7 and Max 10.
The boss of Ryanair, Europe's biggest airline, is still unhappy with Boeing despite its new leadership.
In a recent interview with Reuters, Michael O'Leary voiced concerns about delivery delays.
"Things are continuing to slip slightly, it's been disappointing," he told the news agency.
O'Leary added there was a risk that Ryanair would only receive 20 to 25 of the 737 Max aircraft before next summer rather than the 29 scheduled to be delivered.
The Financial Times reported the airline was supposed to receive 10 jets this month, but O'Leary said, "We'll be lucky if we get five."
"We're working closely with Stephanie Pope and the new team in Boeing, but they continue to disappoint us," he told Reuters.
Pope, appointed in March, heads Boeing's commercial airplane division. The planemaker also has a new CEO, Kelly Ortberg, who took on the role earlier this month.
The AFP reported O'Leary said Boeing has also been paying Ryanair "modest amounts of compensation" for delivery delays.
Boeing slowed production rates following January's Alaska Airlines blowout. A failure in quality control saw a 737 Max leave the factory missing key bolts, causing a door plug to come off the plane in midair.
The industry as a whole is hampered by supply chain problems, too.
O'Leary also appeared unconvinced by the certification timescale for Boeing's 737 Max 10 and Max 7.
He told Reuters the Max 7 was supposed to be certified by the end of this year, but he expects this will happen in the first half of 2025.
He added it was "impossible to know" if certification of the Max 10 would be on time in the first half of 2025.
Certification delays are another task for Boeing's new CEO to contend with. Emirates' president Tim Clark and Qatar Airways' CEO have suggested the long-awaited widebody 777X could be delivered in 2026.
Boeing did not immediately respond to a request for comment from Business Insider.