The US Federal Aviation Administration (FAA) is conducting “voluntary inspections” of Boeing’s B737 Max after ‘Foreign Object Debris’ was found in the fuel tanks of undelivered aircraft.

The FAA defines so-called ‘Foreign Object Debris’ as “any object, live or not, located in an inappropriate location in the airport environment that has the capacity to injure airport or air carrier personnel and damage aircraft.”

Finding the debris “led to a robust internal investigation and immediate corrective actions in our production system,” a Boeing spokesperson told the BBC.

The Max has been grounded since March 2019 after two fatal crashes involving the aircraft. Uncertainty remains over the timeline of its re-certification, with US carriers currently removing it from their schedules until August.

The spokesperson added that the company does not see the issue further delaying the aircraft’s return to service.

The FAA says it is working with Boeing to correct the issue.

Boeing reported its first annual loss in more than two decades in 2019, and predicts the cost of the Max grounding may reach $18 billion.

Boeing posts annual loss and estimates B737 Max cost will reach $18 billion

Elizabeth Pridgeon