Boeing has discovered another software bug on its problem-prone 737 Max, which has been grounded since March of last year.
The newest software issue is at least the third bug to be discovered since a pair of fatal crashes killed 346 in 2018 and 2019.
The worrisome part is that the new issue seems to be the direct result of a previous fix for one of the other bugs, and is more directly related to the original problem with the aircraft.
Specifically, the bug affects a warning light that lets pilots know when the trim system of an aircraft — which lifts or lowers the nose of a plane — is malfunctioning, Bloomberg reported.
That’s according to a statement from Federal Aviation Administration Chief Steve Dickson, who told reporters Thursday that the warning light “had been staying on for longer than a desired period.”
Dickson also said that the FAA is currently evaluating the software issue ahead of a key test flight that could occur within the next few weeks. That test would be a crucial regulatory step before the aircraft is able to carry passengers again.
Shortly after the publication of the Bloomberg article, Boeing issued a statement saying that they’re making a change to the plane’s software to ensure that the indicator light “only illuminates as intended.” (The aircraft maker also said it alerted the FAA about the flaw in January.)
The 737 Max’s other two disclosed software problems included an issue with the aircraft’s computer startup process, as well as an arguably more significant problem that could cause the plane to “dive in a way that pilots had difficulty recovering from in simulator tests.”
It isn’t clear when Boeing is going to get the 737 Max in the air again, but the company said last month that it doesn’t expect the plane to fly again until mid-2020.
The FAA, for its part, said it will only approve the 737 Max “after (their) safety experts are fully satisfied that all safety-related issues are addressed to the FAA’s satisfaction.”
As a result of the plane’s grounding, many U.S. airlines have had to cancel flights. Some airlines have even reached confidential settlements with Boeing over losses that occurred because of the grounding.