Boeing’s ‘fix’ for 737 MAX undergoing more work

US regulator baulks at clearing Boeing 737 MAX for take-off, despite unveiling of software upgrade last week.

Southwest Airlines Boeing 737 MAX aircraft are parked on the tarmac after being grounded. Picture: AFP

Boeing’s “fix” for its 737 MAX aircraft still needs further work before it is submitted to the US regulator, the Federal Aviation Administration.

Despite unveiling the software upgrade and training package to 200 pilots and regulators as well as the media last week, the FAA has not yet received the final package for approval.

Boeing developed the fix following the Lion Air crash last October which shone a light on a flight control system exclusive to the 737 MAX known as MCAS (manoeuvring characteristics augmentation system).

When a second near-new 737 MAX 8 crashed in similar circumstances in Ethiopia last month, the aircraft was grounded worldwide and remains out of action.

A statement from the FAA said time was needed for additional work by Boeing, to ensure that all pertinent issues had been identified and addressed.

“Upon receipt, the FAA will subject Boeing’s completed submission to a rigorous safety review,” said the statement.

“The FAA will not approve the software for installation until the agency is satisfied with the submission.”

MCAS was added to the 737 MAX to account for larger more powerful engines placed slightly forward on the wings, and lowers the nose of the aircraft if it detects a stall or loss of airspeed.

The fix developed by Boeing addresses the problem of MCAS activating as a result of information from just one angle of attack sensor, and disconnects the system if the two sensors disagree.

A Boeing spokesman said they continued to work with the FAA and other regulatory agencies worldwide on the development and certification of the MCAS software update and training program.

“We are working to demonstrate that we have identified and appropriately addressed all certification requirements and will be submitting for FAA review once completed in the coming weeks,” he said.

“Safety is our first priority, and we will take a thorough and methodical approach to the development and testing of the update to ensure we take the time to get it right.”

More than 5000 orders have been placed for 737 MAX aircraft by more than 60 airlines worldwide, and to date 376 have been delivered.

While the model is grounded, Boeing is continuing to manufacture the aeroplanes but it has suspended deliveries.

Garuda Indonesia has cancelled its order and Lion Air’s order has been placed on hold.

No Australian airlines operate the aircraft as yet but Virgin Australia has 30 on order with the first due to be delivered in November, if the airline is completely satisfied it is safe.