Last night Boeing grounded its entire global fleet of 737 Max aircraft after investigators uncovered new evidence at the scene of the fatal Ethiopian Airlines crash.
Regulator, the Federal Aviation Administration, said fresh evidence as well as newly refined satellite data prompted the decision to temporarily ban the jets.
Alex Macheras, independent aviation analyst, says the fact that the US was one of last to ground the jets has damaged Boeing's reputation.
"It's unprecedented to lose two new aircraft in a matter of months," he says.
He tells the Today Programme that it's the first time he's seen a breakdown between an airplane manufacturer and its customers, with Boeing insisting until last night that it had full confidence in the Max 8 plane.