One thing that travelers definitively do not want to hear is that the plane has a bolt or screw loose.

While special metal plane tape is the standard way to make quick fixes on an aircraft that is still deemed fit to fly, videos from panicked passengers who spot airline workers “fixing the plane with tape” periodically blow up on the internet.

Related: A plane with missing windows accidentally took off (here’s what happened)

While tape was not involved this time, airlines and aviation authorities have been instructed to check their aircraft for a missing bolt after one international airline discovered a bolt with a missing nut in the rudder system of a Boeing 737 Max  (BA) – Get Free Report while it was undergoing a routine check-up.

Passengers disembark from the rear door of a Boeing 737 MAX from Ryanair on Oct. 2, 2023. Photo by Thierry Monasse/Getty Images.

Thierry Monasse/Getty Images

‘Inspect 737 Max airplanes and inform us of any findings…’

“The issue identified on the particular airplane has been remedied,” a Boeing representative said in a statement. “Out of an abundance of caution, we are recommending operators inspect their 737 Max airplanes and inform us of any findings.”

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Aviation authorities in multiple countries have also echoed Boeing’s instructions to airlines. In the U.S., the Federal Aviation Administration (FAA) said that it is “closely monitoring” the inspections and and “will consider additional action based on any further discovery of loose or missing hardware.”

Having all the parts in the rudder system present and functioning properly is considered crucial to the aircraft’s safety and required a “double inspection” even before the latest incident. As part of thew new inspection instructions, those conducting the inspection will need to remove the plane’s access panel and visually make sure that all the nuts and bolts are in place on each plane that is the same model as the one where the missing part was discovered.

Here is how airlines are responding to the discovery of the loose bolt

“Under consultation with the FAA, Boeing has issued a Multi-Operator Message (MOM), urging operators of newer single-aisle airplanes to inspect specific tie rods that control rudder movement for possible loose hardware,” the government agency said. “The agency is asking the airlines to work through their approved Safety Management Systems to identify whether any loose hardware has been detected previously and to provide the agency with details on how quickly these two-hour inspections can be completed.”

Over in India, the country’s Directorate General of Civil Aviation (DGCA) has also been monitoring the situation as many of the country’s airlines recently invested in new Boeing 737 Max planes.

While a loose bolt is easier to miss, an Airbus A321neo  (EADSF) – Get Free Report with several missing windows took off from the ground at London’s Stansted Airport last November. After passengers started complaining of it being “loud and chilly,” a flight attendant inspected the plane and noticed that the window seal on one of the windows “was flapping in the airflow and the windowpane appeared to have slipped down.”

The pilot had to make a quick descent (the plane had not flown far and there were no injuries) while an initial investigation found that the windows were damaged by the high-powered food lights that were used when the plane was being filmed for a movie a day before and then were somehow missed in a pre-flight check.