Boeing’s troubled 737 Max aircraft has suffered another setback after debris was found in the fuel tanks of some of the grounded planes during routine inspections.
Foreign object debris (FOD) is an industry term for objects such as tools, rags, and metal shavings that are left behind by workers during an aircraft’s production. Such debris, which could cause problems during a plane’s flight, has also been found in some of Boeing’s other jets in the past.
First reported by specialist aviation website Leeham News and later confirmed by Boeing, the debris was found in the fuel tanks of some of Boeing’s 400 newly built but undelivered Max jets during inspections at the aviation giant’s storage sites in Washington and Texas.
Inspecting a fuel tank takes about three days per plane as it has to be drained and vapors dissipated prior to it being opened. It’s not currently clear how many 737 Max tanks have been inspected so far, and how many tanks were found with debris inside.
In a memo to Boeing employees obtained by Leeham News, Mark Jenks, the vice president and general manager of the 737 program, confirmed that Boeing was “taking action after a range of FOD was recently found in the fuel tanks of several 737 Max airplanes in storage.”
Jenks added that the discovery was “absolutely unacceptable” and that the team will work to eliminate FOD from Boeing’s production system.
The company later confirmed the memo’s authenticity but said the issue shouldn’t cause any additional delays to its plan to get the aircraft in the skies again.
The 737 Max was grounded globally in 2019 following two crashes in five months. The first one occurred in October 2018 when a Lion Air flight came down soon after taking off from Jakarta, Indonesia, resulting in the deaths of all 157 passengers and crew. Then, in March 2019, an Ethiopian Airlines jet crashed near Addis Ababa in Ethiopia, killing 189 people on board.
It was later determined that the crashes were caused by a fault with the aircraft’s software that sent the doomed planes into nosedives. Boeing is testing a fix for the fault and hopes to get the Max back into commercial service in the coming months once the Federal Aviation Administration certifies the plane as airworthy.
The discovery of foreign objects in the fuel tanks is the latest in a slew of problems to hit Boeing’s beleaguered plane as airlines around the world wonder when their Max jets will be able to fly again.
Beside the central software-related issue that brought the planes down, problems have also been found with the wiring that controls the tail of the 737 Max, as well as an issue that had the potential to prevent the jet’s flight control computers from starting up and verifying that they’re ready for flight. More recently, a fault was discovered with an important indicator light on the aircraft’s flight deck.
The ongoing challenges prompted Boeing to suspend production of the Max until regulators clear it for takeoff again.