Boeing says it needs more time to upgrade its software to make the stall-prevention system in 737 MAX aircraft less aggressive

The software upgrade is needed to make the stall-prevention system in Boeing’s 737 MAX aircraft less aggressive

Two of the new aircraft have crashed within five months of each other, with 346 lives lost

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A Boeing 737 MAX 9 aircraft on the tarmac at Boeing’s factory in Renton, Washington state on March 12, 2019. Photo: AFP

Published: 12:00pm, 2 Apr 2019Updated: 10:45pm, 2 Apr 2019

Boeing says it needs more time to finish a software upgrade for its grounded 737 MAX jetliners as company engineers update a stall-prevention system linked to two fatal crashes in five months.

The planemaker said last week it would submit final paperwork for the revamp to the Federal Aviation Administration by March 29 to make the system - known as MCAS - less aggressive in pushing down a plane’s nose, and to add redundancy so that it’s less likely to activate when other systems malfunction.

Now Boeing says the update won’t be ready until the “coming weeks.”

An issue with integrating the software fix and the plane’s existing flight-control architecture came to light as Boeing did a final audit of the upgrade, according to a person briefed on the work. Ensuring that MCAS will perform as desired while not interfering with existing flight controls isn’t expected to be a significant challenge said the person, who wasn’t authorised to speak about the work and asked not to be identified.

Indonesian National Transportation Safety Commission (KNKT) officials examine a turbine engine from the Lion Air flight JT610 at Tanjung Priok port in Jakarta on November 4, 2018. The Boeing 737 MAX aircraft had crashed a month earlier into the Java Sea, killing all on board. Photo: REUTERS

“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,” Boeing said in an email on Monday. “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.”