United and Southwest Airlines Announce Extended Boeing 737 Max Cancellations Amid New Software Issue

Illustration for article titled United and Southwest Airlines Announce Extended Boeing 737 Max Cancellations Amid New Software Issue
Image: Stephen Brashear (Getty)

The absolute shitshow that is Boeing’s ongoing 737 Max headache saw yet another safety issue come to light this week, resulting in further flight cancellations by U.S. carriers with the aircraft in their fleets.

United Airlines announced Wednesday that it has extended previous cancellations to Sep. 3, the Guardian reported. Meanwhile, Southwest Airlines, which previously announced cancellations through the beginning of September, said in a statement Thursday that it was removing 737 Max flights from its schedule through Oct. 1. The airline said the changes would affect roughly 150 flights per day.

The announcements come amid reports that test pilots with the Federal Aviation Administration discovered a new critical safety issue with the 737 Max’s anti-stall software system, called MCAS, during flight simulations. According to a source familiar with the matter who spoke to the Washington Post, these pilots were worried they weren’t able to “quickly and easily follow the required recovery procedures.”


The FAA said in a statement Wednesday that it “found a potential risk that Boeing must mitigate.” The Washington Post reported the flaw as being separate from the one suspected to have played a major role in two 737 Max crashes that resulted in the deaths of 346 people.

Boeing said Wednesday that it was working on a fix for the software issue that would “reduce pilot workload by accounting for a potential source of uncommanded stabilizer motion.”

“During the FAA’s review of the 737 MAX software update and recent simulator sessions, the Federal Aviation Administration (FAA) identified an additional requirement that it has asked the company to address through the software changes that the company has been developing for the past eight months,” the company said in a statement. “Boeing agrees with the FAA’s decision and request, and is working on the required software.”

The FAA officially grounded the jets in March, and it’s not clear when the aircraft will again be cleared for commercial flight. The FAA said this week that it is “following a thorough process, not a prescribed timeline” in reviewing the aircraft.


As they await approval from the FAA, both carriers and Boeing appear to be willing to do just about anything to help remedy the shattered reputation of their 737 Max jets and convince customers they’re safe for flight. Boeing says it’s open to changing the name of the planes if that helps overhaul branding. Meanwhile, American Airlines, which recently extended its own cancellations of flights through the beginning of September, appears prepared to stick its executives on the planes to reassure the public.

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I won’t lie - I need to nitpick this statement:

The announcements come amid reports that test pilots with the Federal Aviation Administration discovered a new critical safety issue with the 737 Max’s anti-stall software system, called MCAS, during flight simulations.

The MCAS is not an “Anti Stall” system.... not entirely. To understand just WHY Boeing’s fubar in this is so bad, you have to understand what the MCAS was supposed to do. And its nutbar once you realize it.

Boeing’s Maneuvering Characteristics Augmentation System is designed, primarily, to make the Boeing 737 Max respond like previous generation Boeing 737 aircraft. The reason for the MCAS is simple: Boeing inverted the engines. This changed the position of the engines and the distribution of mass on the wings. This was so that the new, much larger engines, could clear the ground during takeoff and approach without having to change the Aircraft’s superstructure to accommodate a taller landing gear system (which would have increased costs and still altered flight characteristics significantly). This changed the wing’s chord (the line between the leading and trailing edge of an aerofoil) - and altered the distribution of the forces the wing bears during flight and the way this affects the center of gravity of the aircraft. This adjustment meant that the CG was moved back along the fuselage such that the aircraft has different handling characteristics than the average 737.

MCAS was brought in to make the aircraft appear to the pilots to fly *just like* the old 737. Why? Well, the CG move had an affect on the plane’s tendencies in flight. Not enough to make the plane un-flyable but enough that if you had flown a 737 before this would feel like a completely different aircraft. This is why the aircraft also has a second AOA sensor - the first one was in the wrong place for the new CG. So why MCAS? Because Boeing didn’t want pilots to have to re-certify on this aircraft. MCAS was supposed to make the aircraft appear to the pilot to fly *just like* the old 737 - so they could just take a few notes from an iPad and fly away. Yes. Boeing did this so that Airlines didn’t have to train and certify their pilots on this aircraft, which would have drastically increased the total cost of ownership and they would not have sold as many.

Think of it this way - you’re an F1 driver. You know F1 cars. But suddenly someone wants you to race a panel van - like immediately - and you’ve never driven a panel van. Now, imagine that in order to save you the hassle of learning how to drive a panel van and race it, someone rigged it up so that the panel van felt like an F1 car to you. And now you can drive that panel van like an F1 car, and the software/hardware will compensate and adapt for the characteristics of the Panel Van. That’s MCAS and it has been used lots before and with success. And to be fair to Boeing - the difference between the Max and previous 737's is more like the difference between a corvette and a porsche. Its enough that you’d want to spend a lot of time with each one before you took it to a track/daily drive but not so much that you’d be afraid to drive it around the block under normal conditions so long as you knew each one had their quirks.

To be very honest? The additional AOA sensor and the new electronic trim-stab system did mean that, on paper, this aircraft was a lot *better* than the old 737 (and a lot cheaper to run with the new engines). Unfortunately Boeing decided to cut corners in two idiotic places: first they made “optional” a set of warning lights that would allow the pilot to instantly know if the two AOA sensors were disagreeing on the Aircraft’s attitude. This optional package also included a single-press button to override the MCAS and let the meat computers handle it. Boeing obviously thought this would be “unnecessary” and... were probably concerned about pilots pressing this and suddenly having a plane that didn’t fly like a 737 should, which would bring up that pesky certification/training process again. Second, there was also a flight package that would add an override and indicator for the electronic trim-stab actions so that the pilots would know what the system was doing AND be able to quickly override the MCAS during flight. Again, if the sensors are in agreement, the MCAS will make everything fly nice and familiar and was considered a convenience option. Of course, the functions could be accessed by going through the flight computer and inputting a set of codes from the checklist procedures that would take about 1-2 minutes to accomplish an override. Easy peasy during takeoff and landing when you’re losing control authority because the damn thing is trying to nose-dive.