The FAA Approves 737 MAX Test Flights
Matthew Greenwood posted on July 01, 2020 |
Recertification of the troubled plane could finally be in sight.

The Federal Aviation Administration (FAA) has cleared the Boeing 737 MAX for test flights—a major step toward getting the controversial aircraft back in the air.

The FAA informed Congress that it had completed its review of Boeing’s proposed fixes for the aircraft. Now, those fixes need to be tested in flight. Testing has already started, with the first test flight completed on June 29. The tests will include a battery of flight maneuvers and emergency procedures conducted by FAA pilots.

Has the MCAS Been Fixed?

At the center of the recertification process is how the overhauled Maneuvering Characteristics Augmentation System (MCAS) software will function. Malfunctions by MCAS  caused the two fatal crashes that resulted in the grounding of the plane in the first place. The MCAS now takes input from multiple angle-of-attack sensors rather than just one damage-prone sensor as originally designed.

Boeing submitted its proposed fixes to the FAA over a year ago, but the regulator’s review found another flaw in the system that needed correcting: a flawed microprocessor.

Boeing has overhauled the MAX’s entire flight control system to take input from both flight computers simultaneously. Before its grounding, the aircraft would use one computer on a flight, then switch to the other on a subsequent flight. Restructuring the system in this manner, when so many of the aircraft’s systems are independent, is a complex task—and the FAA is auditing every system of the plane to ensure that Boeing’s solution works.

But additional problems surfaced. The flight control computer would cause an indicator light to activate falsely. Issues were found in the software used to power up the plane. And there were concerns that the wires that help maneuver the aircraft’s tail were potentially bundled too closely together.

Most of those problems are tied to the MAX’s computer systems. The 737 design is half a century old now, and the planes use computers with 16-bit processing power: that’s what you need to play Super Mario. It’s also been enough to run a 737 for decades—any variant, that is, except for the MAX. The MAX features bigger and heavier engines, and Boeing has been asking the computers to run aerodynamic management software that may be too much for their aging systems.

It doesn’t appear that Boeing has replaced the MAX’s computers—so there may still be a significant load on the aircraft’s processors.

Even if the test flights are successful, don’t expect to see the jet back in the air anytime soon: the process could take months.

The Controversy Won’t End with Recertification

If the FAA clears the MAX for a return to service, it won’t necessarily mean clear skies ahead for the controversial jet. The crashes and subsequent public hearings have severely dented the plane’s—and the manufacturer’s—reputations in the public eye. In fact, a senior Boeing engineer who blew the whistle on the MAX’s problems last year has recently raised alarms about the passenger jet that go beyond just the MCAS.

“I have no doubt the FAA and lawmakers are under considerable pressure to allow the 737 MAX to return to service as quickly as possible and as soon as the public MCAS flaw is fixed,” said Curtis Ewbank in his letter.  “However, given the numerous other known flaws in the airframe, it will be just a matter of time before another flight crew is overwhelmed by a design flaw known to Boeing and further lives are senselessly lost.”

The FAA has earned itself a black eye over its lapses in oversight of the MAX’s original certification, and will be under intense scrutiny as it reviews Boeing’s aircraft. The agency is perceived as having been far too cozy with the manufacturer in the past—allowing Boeing to more or less perform its own certification work.

And beyond the FAA, Boeing will also have to comply with regulators from other jurisdictions around the globe to allow the MAX to fly in foreign airspace—regulators who may no longer feel the need to just follow the FAA’s lead.

Boeing Restarts Its Plane Factories

Boeing shut down production of the 737 in January—and significantly slowed assembly lines across its operations because of COVID-19. But 737 MAX production is ramping up again.

Boeing is adopting a phased approach, slowly increasing production over the rest of the year at its Renton, Wash., facility—which has three assembly lines dedicated to the MAX. The facility was pumping out 42 737 MAX aircraft a month throughout 2019, even after the fleet was grounded last March, resulting in a significant backlog. The plane manufacturer intends to produce 31 planes a month in 2021, and it will be implementing over a dozen workplace safety and product quality control initiatives in its factories as it resumes production.

This is happening at a precarious time for Boeing. Doubts about the MAX, and an air travel industry walloped by COVID-19, have caused upheaval in the aerospace sector. In fact, one of Boeing’s major European clients, Norwegian Air Shuttle, canceled its order for 92 MAX planes—on the same day as the aircraft’s first test flight.

Continued Uncertainty for the MAX

Have the MAX’s problems been solved, making it the safest airplane in the sky? Or is the model too flawed to ever be truly safe?

Boeing’s first test flight is now complete.

Boeing is under intense pressure to produce a fixed plane—but it seems sure that the MAX is ready to fly again. “When the MAX returns to service, it will be one of the most thoroughly scrutinized aircraft in history, and we have full confidence in its safety,” the company said.


Read more about the crisis at 737 MAX Senate Hearings Expose Deep Flaws at Boeing.

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