Airlines across the world have been told to inspect their Boeing 737 Max jets after one unnamed airline discovered a missing part on the plane, which has already been subject to years of controversy and even deaths.
The aviation giant instructed operators to look for a possible loose bolt in the rudder control system, according to the US Federal Aviation Administration (FAA).
The rudder controls movement of the aircraft about its vertical axis while in flight.
The inspections were prompted by an airline finding a bolt with a missing nut while performing routine maintenance.
FAA said it was an international operator that made the discovery.
A nut that was not properly tightened was also found on a second undelivered aircraft.
“The FAA will consider additional action based on any further discovery of loose or missing hardware,” the regulator said.
A Boeing spokesperson said the plane with the missing nut had been fixed.
“The issue identified on the particular airplane has been remedied,” the spokesperson said.
“Out of an abundance of caution, we are recommending operators inspect their 737 Max aeroplanes and inform us of any findings.
“We informed the FAA and our customers and will continue to keep them aware of the progress.”
Boeing said there was 1370 of the aircraft worldwide that it is urging are checked.
Virgin Australia has three and Bonza is understood to have six of the aircraft.
news.com.au has contacted both airlines for comment.
The inspection only lasts about two hours, but the issue comes on the heels of other manufacturing and production problems that forced the company to lower its delivery targets for the 737 Max this year.
The aircraft has a troubled history.
Two 737 Max planes – Ethiopian Airlines flight 302 and Indonesian carrier Lion Air flight 610 – crashed in October 2018 and March 2019, killing 346 people.
The jets were grounded until they were cleared to fly again in the US in 2020 and in the UK and EU in 2021.
It cost Boeing more than $US20 billion, making it one of the most expensive corporate tragedies in history, according to CNN.
CNN safety analyst David Soucie said on Friday: “If the airplane left the factory with this missing part, it indicates the past three years of safety culture improvements and improved inspections on critical safety of flight systems at Boeing isn’t working.”
Boeing shares dipped 0.7 per cent on Thursday in New York (Friday AEDT).