“These request letters represent only the start of our investigation and finding answers to our questions will take some time.” Boeing has said the launch of improved software for its grounded 737 Max aircraft will be delayed . It had been expected to announce the upgrades at the end of March but said the announcement would be now made in “ two weeks ” . Federal Aviation Administration ( FAA ) acting administrator David Elwell said the 737 Max would be grounded until the agency ’s own analysis of the aircraft found it safe to fly again . Airlines using the aircraft are re - organising schedules to cope with an indefinite grounding . Meanwhile , US lawmakers and officials are reviewing the certification of the 737 Max .
Boeing has said the launch of improved software for its grounded 737 Max aircraft will be delayed . It had been expected to announce the upgrades at the end of March but said the announcement would be now made in “ two weeks ” . Federal Aviation Administration ( FAA ) acting administrator David Elwell said the 737 Max would be grounded until the agency ’s own analysis of the aircraft found it safe to fly again . Airlines using the aircraft are re - organising schedules to cope with an indefinite grounding . Meanwhile , US lawmakers and officials are reviewing the certification of the 737 Max .