It was among the most advanced commercial planes in the sky. But when two crashes occurred within four months of one another, the Boeing 737 MAX was grounded and the company lost billions.
Now, Boeing plans to bring the plane back in early 2020. They say that they have corrected the design flaws but how the Boeing 737 MAX will be received remains to be seen.
For Adeel Khalid, a professor of aerospace engineering at Kennesaw State University who specializes in aircraft design optimization and a licensed pilot, the jury is still out.
“Even if someone came to me to say they fixed all of the problems in the plane, I would have reservations about flying it myself,” says Khalid. “It’s understandable that some airlines are questioning why they should buy it back.”
So what went wrong?
“The Boeing 737 plane was destined to be the latest and greatest aircraft.”Adeel Khalid, professor of aerospace engineering at Kennesaw State University
“It was built on the ever-popular Boeing 737 platform, which has decades of commercial success behind it – only this variant was equipped with even more automation than previous versions.”
Among the innovations included on the Boeing 737 MAX was the Maneuvering Characteristics Augmentation System (MCAS), designed to aid pilots as they pitch the nose of plane upward and downward. In theory, it was designed to protect the aircraft from imminent danger. But in both accidents, Khalid says, it was a liability.
Typically, a pilot would input information in to the plane’s computer, such as desired altitude and direction of travel, and the computer would take over the controls from there. However, computers rely on instruments, and the Boeing 737 MAXs involved in the two crashes demonstrated faulty angle of attack indicators.
After taking off, the indicators dictated the computers to tip the nose of the aircraft down. The pilots, sensing a problem, tried to pull the nose back up. Unable to override the MCAS system, the pilots were unable to recover the aircraft, causing them to plummet.
“There are several flaws with this particular design, the first of which was the reliance on a single instrument to feed into MCAS,” says Khalid, who coordinates the aerospace engineering program in KSU’s Southern Polytechnic College of Engineering and Engineering Technology. “Instead, Boeing should have focused on redundancy. When one instrument fails, another should be readily available to take over and prevent an accident.”
Even with the instruments failing, a pilot should also have a way to override MCAS to correct the flight path. However, the pilots either weren’t trained to do so or weren’t able to disconnect the system in time to save the lives of 346 people.
Soon after the second crash, Boeing issued a statement in agreement with U.S. Federal Aviation Administration’s recommendation to suspend operations of the aircraft worldwide, a decision costing the company billions. Though painful, it was the right move to make, Khalid says, as more MCAS flaws have been discovered with the planes grounded.
“Thankfully, they’re now discovering this instead of putting them back in service to find later,” he says.
Though estimates have the aircraft set to return to airworthiness by early 2020, it will take more time to build back public trust in an aircraft most known for its design flaws, he added. And if that weren’t enough, an engineer who assisted in the development of the aircraft has come forward this month to say Boeing officials ignored his recommended safety upgrades prior to the two fatal accidents.