The CEO of Europe's busiest airline says he's had long-running issues with Boeing's quality control, including finding a stray wrench under a plane's floor

• Ryanair CEO Michael O'Leary said the airline has complained to Boeing about quality-control problems.
• He said they found "lots of small defects" like a wrench left under one plane's floor.
• But O'Leary also said he had the "utmost confidence'" in Boeing CEO Dave Calhoun.

The CEO of Europe's biggest airline by passenger numbers said he complained to Boeing about quality-control problems including a wrench left inside a plane, per The Independent.

Ryanair CEO Michael O'Leary said in a Tuesday press conference: "We have been loud in our complaints about the lack of quality control of Boeing over the last two years."

"It is not acceptable that aircraft get delivered at less than 100%," he added.

The ultra-low-cost carrier is the world's third-biggest operator of the Boeing 737 Max, but hasn't ordered any of the 737 Max 9 jet which was involved in the Alaska Airlines blowout.

Since the incident, Boeing's quality-control process has come under increasing scrutiny as more issues with the Max 9 emerged.

Both Alaska Airlines and United Airlines, the largest operators of that jet, found loose bolts during inspections.

And investigators from the National Transportation Safety Board are examining the door plug from Flight 1282 to determine whether four missing bolts attaching it to the plane were ever installed.

"Coming out of COVID, we were taking aircraft deliveries and finding lots of small defects and things not fitted correctly," O'Leary told The Independent.

He added that during the 48-hour checks carried out on the planes when delivered to Ryanair, a wrench was discovered under the floor of one aircraft.

Despite these problems, O'Leary backed Boeing CEO Dave Calhoun, saying he has "utmost confidence" in him and the chief financial officer, per The Independent.

According to the newspaper, the Ryanair boss also said there had been improvements as the 12 planes delivered from last October to December were "the best deliveries we've taken from Boeing."

On Monday, Boeing announced new measures to improve its quality control system, including more inspections; an independent assessment; and opening its factories to 737 operators to review procedures.

The BBC reported that Boeing asked Ryanair to send extra engineers to its factory to oversee quality checks.