Can you still fail with a Quality system?

It has been a tough year for Boeing. 

Five days ago, Delta Airlines flight 982 from Atlanta to Bogotá (757) lost a wheel while taxiing for departure.

On January 13, All-Nippon Airways flight 1182 from Sapporo to Toyama (737-800) found a crack in the cockpit window shortly after takeoff. 

On January 5, a door-sized plug blew out of the airframe of Alaska Airlines flight 1282 (737 MAX-9) six minutes after the plane took off from Portland International Airport.  

Image from the NTSB investigation of the Jan. 5 accident involving Alaska Airlines Flight 1282 on a Boeing 737-9 MAX.
Captured on Jan. 7. (Image in the public domain.)

A few days before that, Boeing asked the FAA to exempt a new model of the 737 MAX from a safety standard which was implemented last summer, when it became clear that using an anti-icing system in dry air could overheat engine-housing parts, which could then cause them to break away from the plane. (The Associated Press reports that "Boeing needs the exemption to begin delivering the new, smaller Max 7 to airlines.") 

Back in December, Boeing asked airlines to inspect their 737 MAX planes for a loose bolt in the rudder control system. (This month Boeing followed up by issuing a bulletin to their suppliers to ensure that all bolts are properly torqued.)

Last April, Boeing said that production of the 737 MAX could be delayed because one supplier used a “non-standard manufacturing process” during installation of some fittings.

Then there are the engine fires: 

• United Airlines flight 129 from Houston to Rio de Janeiro (767) on March 28
• United Airlines flight 1509 from San Francisco to Honolulu (777-300) on June 5
• United Airlines flight 2376 from Fort Lauderdale to Newark (737-900 MAX) on June 28
• United Airlines flight 329 from Denver to Boston (737-9 MAX) on September 30
• the S7 flight from Novosibirsk to Moscow (737-800) on December 7*
• United Airlines flight 551 from Newark to Denver (737-900ER), with an emergency landing in Wichita, on December 14
• and Atlas Air flight 95 from Miami to San Juan, Puerto Rico (747-8), just six days ago on January 19. 

What's an airplane manufacturer to do?

As a first answer, let me suggest ... that's why they have a Quality system.

It sounds crazy to look at a string of failures and conclude, "That's why they have a Quality system," but in fact it's true. No Quality system can prevent all possible errors. The best Quality systems reduce the number of failures until there are very few, but even so there is always room for improvement.

And in a sense it is remarkable that the number of failures has been so small. The FAA handles an average of 45,000 flights per day in the United States alone, or well over sixteen million per year. Let's assume Boeing made half of those planes (and is therefore responsible for eight million flights a year), which is probably close enough.** A dozen errors in a year—even if you think they've been under-reported and the real number is a few dozen—is a very small fraction of eight million.

The next thing that a Quality system gives you is a way to respond when something goes wrong.*** Maybe the most remarkable fact about all the failures I listed above is that nobody was seriously hurt in any of them. Even when the door blew out of the airframe, some phones and other belongings fell out but the only injuries were minor. In each case, the airline personnel knew what to do so that a problem didn't become a catastrophe. Even Boeing's bulletin to their suppliers is clearly a response—no doubt defined by their Quality system—to a discovered Quality defect in purchased materials.

Even if you certify your Quality system to a management system standard (such as ISO 9001, or AS9100 for aviation)****, that doesn't guarantee that your products will be perfect. All it does is to certify that your system meets a defined threshold of goodness. Using that system every day to get the work done is still a challenge for every organization.

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* S7 is a Russian airline, and current sanctions on international trade with Russia make it impossible for them to import spare parts from Boeing; so it is possible that this incident could have resulted from inadequate maintenance. 

** Boeing's website says that they have manufactured "almost half the world fleet" of commercial jetliners, and that "about 90 percent of the world’s cargo is carried onboard Boeing planes."

*** That was the most important point in this post from 2021: no Quality system can prevent (for example) someone going crazy just before he does a critical operation. But a Quality system can define how you respond after the fact, to contain and correct the problem. 

**** Yes, I remember that Boeing isn't formally certified to AS9100, though they flow the requirements down to their suppliers and clearly state that their internal Quality system meets the AS9100 requirements. Note that I said "Even if." Whether they would do better if they were in fact certified is a question for another day.