Chesley "Sully" Sullenberger, who in 2009 landed a US Airways flight safely on the Hudson River in New York, told a congressional panel on Wednesday that pilots of the now-grounded 737 Max should get new simulator training before the plane returns to service.

He also said that the Federal Aviation Administration's system of certifying new aircraft is not working after two deadly crashes since October killed 346 people: "Our current system of aircraft design and certification has failed us."

Boeing said in May it had completed an update to software, known as MCAS, which would stop erroneous data from triggering an anti-stall system that automatically turned down the noses of the two planes that crashed, despite pilot efforts to stop it.