At the Paris Air Show Boeing, executives apologized for the 737 MAX crashes that left 346 dead, grounded the planes worldwide and created many questions that still haven’t been answered.
“We are very sorry for the loss of lives,” said Kevin McAllister, CEO of Boeing’s commercial aircraft. He also apologized to airlines and suppliers that have seen their business dwindle due to the grounding of the planes.
The Paris Air Show was an opportunity for the aerospace giant to reassure many of its airline customers and suppliers about proposed solutions for the Max. Boeing was not expecting a repeat in Paris of the landmark showing at last year’s Farnsworth Air Show—its focus was very different this time. Boeing concentrated on spending “a significant amount of time with our customers and suppliers as we work on delivering on our commitments to safety and quality,” McAllister said.
The software malfunction that led to the two crashes in five months—explained in detail on engineering.com—still hasn’t been fixed. While Boeing expressed confidence in its proposed fixes, the aerospace giant couldn’t answer when the 737 was expected to fly again.
Boeing has acknowledged that it didn’t properly inform regulators about changes to the Maneuvering Characteristics Augmentation System (MCAS) cockpit warning system in the 737 Max that led to the crashes. The MCAS was designed to work in the background, activating in rare circumstances to nudge the Max’s nose down and help the aircraft maneuver more smoothly at high speeds in certain conditions.
While the plane was still in development, Boeing removed one of two types of sensors from the MCAS, making it more aggressive—and more risky. The final model that was rolled out to airlines appears to have been overly reliant on the one remaining angle-of-attack sensor without a safeguard in case the sensor malfunctioned. In both crashes, the sensor malfunctioned and sent the planes into a nosedive that pilots couldn’t recover from. That sensor is prone to damage from impacts such as bird strikes or bumps from equipment and mechanics, increasing the danger of relying on just that one sensor.
Boeing did not tell the regulators tasked with testing and approving the plane about the change in the system. This led the FAA, which had certified the original MCAS, to make faulty assumptions for pilot training requirements. In fact, Boeing requested that the description of the MCAS be removed from the pilot’s manual without telling the regulator that the MCAS had been changed—that manual has since been updated. The FAA complied, assuming that the system would activate only in rare conditions. But Boeing engineers had expanded the role of the system to avoid stalls in various situations, giving it a bigger role than the regulator was led to believe.
The plane maker also didn’t update the aircraft maintenance manual it provided to airlines until after April 2017, when Max deliveries were already underway.
The pilots in the doomed flights likely didn’t even know about system they were wrestling with for control of the aircraft. Had they, and the regulators, known about the altered MCAS, the disasters may have been avoided.
It appears that many of Boeing’s own staff—test pilots and engineers included—didn’t know about changes to the MCAS either. One former engineer bluntly said when hearing about the reliance on only one sensor, “that’s nuts.”
Boeing has promised that it is reworking the MCAS to more closely resemble the original system, relying on two sensors and operating less aggressively. It has three layers of additional protection. The company has flown more than 280 Max test flights with the new software to prove its airworthiness.
The FAA and other regulators around the world are hesitant to declare the 737 flight-ready again. Once Boeing has addressed the FAA’s concerns, the regulator will perform a certification flight on the 737 with the new software. The FAA will then need time to review the data from the flight to ensure the revamped MCAS is compliant with regulations. If the FAA verifies Boeing’s fixes, it will lift the flight ban on the aircraft. The regulator said this might happen by December but has not committed to a timeline.
That estimate doesn’t factor in any additional checks that other regulators around the world may want to perform after FAA certification. If regulators require pilots to be re-trained, that will further delay the Max’s return. The FAA is not expected to require full-flight simulator training sessions, though the Allied Pilot Association has told Congress it should be mandatory.
“Safety is absolutely sacred to us at the Boeing company,” McAllister said. “This is a pivotal moment for us. It’s an opportunity where we have to capture every possible learning. It’s a time when we have got to be humble and introspective and make sure an accident like this never happens again.”
There are positive signs for the future of the 737 Max. In Paris, Boeing struck a deal with IAG, the parent company of British Airways and other airlines, for 200 Max jets. It’s the first sale of the plane since the fleet was grounded. IAG expressed confidence that the FAA would certify the planes as airworthy soon.
While the 737 Max won’t fly again for quite a while, there does seem to be growing confidence that it will return to the skies at some point with additional safety measures. Boeing will have its hands full convincing regulators, airlines and passengers to step on board again.
Read more about Boeing’s troubled passenger jet at Boeing Is Running Out of Room for Its Planes as the 737 Max Crisis Continues.