Boeing’s bid to see its 737 Max return to the skies faces a pivotal week with flight safety tests expected to begin.
Pilots and technical experts from regulators and the company are understood to be planning three days of tests, possibly starting on Monday.
Boeing’s best-selling aircraft was grounded last year after two crashes killed all 346 people on the flights.
The tests are a milestone for Boeing, but even if they go well, months of further safety checks will be needed.
Aviation regulators grounded the 737 Max about 15 months ago following two crashes – a Lion Air flight and an Ethiopian Airlines flight – within five months of each other.
Investigators blamed faults in the flight control system, which Boeing has been overhauling for months in order to meet new safety demands.
A 737 Max loaded with test equipment will run through a series of mid-air scenarios near Boeing’s manufacturing base at Seattle.
According to Reuters, which first reported the news, pilots will intentionally trigger the reprogrammed stall-prevention software known as MCAS, blamed for both crashes.
The BBC understands that both the FAA, which is leading the testing, and Boeing, are hopeful that the process will get under way on Monday, barring last minutes hitches.
The FAA confirmed on Sunday in an email to the US Congress that it had approved key certification test flights for the grounded 737 Max.