Four Missing Bolts. Hundreds of Assumptions.
- Mike Mason
- 5 days ago
- 6 min read
On 5 January 2024, Alaska Airlines Flight 1282 departed Portland, Oregon, on what should have been an entirely routine flight to California. The Boeing 737 MAX 9 had climbed to around 16,000 feet when passengers heard a loud bang followed by an explosive rush of air as a section of the fuselage tore away from the aircraft. As you'd expect, oxygen masks deployed and loose objects were pulled from the cabin. The flight crew immediately began an emergency descent before returning safely to Portland.
Remarkably, despite the dramatic nature of the event, everyone on board survived.
The image of the aircraft with a gaping hole in its side quickly spread around the world. For many people, the immediate assumption was that this must have been another example of Boeing's troubled quality record. Given everything that had happened with the 737 MAX over the previous few years, that conclusion felt almost inevitable. It was neat, understandable and emotionally satisfying. Boeing had made another mistake.
As the investigation progressed, however, the story became considerably more interesting. Investigators discovered that the door plug, the panel that had separated from the aircraft during flight, had been removed during manufacture so that repairs could be carried out to damaged rivets. When it was reinstalled, four retaining bolts that were designed to prevent the plug moving upwards had not been refitted. They hadn't failed in service nor sheared under load. They just.... weren't there.
That's impossible right? How does an aircraft leave the factory with four critical bolts missing? Surely somebody forgot to fit them. Surely somebody failed an inspection. Surely somebody signed off work they hadn't completed. Those are all reasonable statements or questions. They're also examples of what we call the first story. They focus on the individual immediately before the failure and assume that's where the explanation lies.
A more interesting question isn't, "Who forgot the bolts?" It's, "How did an organisation allow four missing bolts to pass unnoticed through a production system designed specifically to stop that happening?"
The problem wasn't four bolts
One of the themes running through these blogs has been the difference between the trigger and the cause. The MV Dali wasn't really about an electrical fault. The Royal Navy F-35 wasn't really about an intake blank. The Mull of Kintyre wasn't really about a Chinook flying into cloud. Each of those accidents challenged us to look beyond the obvious explanation and ask what was happening within the wider system.
The Alaska Airlines incident deserves the same treatment. The missing bolts explain what happened, but they tell us remarkably little about why the system failed to detect their absence. Focusing entirely on the bolts risks missing the far more valuable lesson. Somewhere between removing the door plug, carrying out repairs, reinstalling the panel, inspecting the work and delivering the aircraft, ownership became blurred.
Information moved between people and assumptions replaced verification. A series of perfectly ordinary activities combined to create an extraordinary outcome. This sort of combination of events is rarely how organisations imagine accidents occurring. We like to picture catastrophic failures beginning with catastrophic mistakes. The reality is usually much more discrete: A task is handed over. Somebody assumes the previous team completed something. Another person believes somebody else has already checked it. Documentation appears to support that assumption, so nobody feels the need to ask another question. Nothing looks particularly alarming because each individual step makes sense when viewed in isolation.
By the time the aircraft leaves the factory, everyone believes someone else owned the problem.
Handover is one of the most underestimated risks in any organisation
The longer I work with organisations outside aviation, the more I realise that almost every team has its own version of four missing bolts. Projects move between departments. Patients move between clinical teams. Equipment passes from maintenance to operations. Contractors finish their work and hand assets back to the client. Managers change roles. Shift workers go home. None of those activities are unusual. In fact, they're so common that we often stop thinking about the risks they introduce.
Every handover creates an opportunity for assumptions to creep in. Most of the time those assumptions are harmless because reality happens to match our expectations. Occasionally, however, they don't. That's when organisations discover that ownership isn't something that can simply be written on an organisational chart. Ownership exists only when everybody involved shares the same understanding of who is responsible for the next action.
The unwelcome reality is that responsibility often becomes most unclear precisely when work passes between teams. Everyone is acting professionally. Everyone is trying to do the right thing. Yet each person has a slightly different understanding of what has already been completed and what still remains to be done. It's in those small gaps between understanding that accident chains quietly begin to develop.
Good systems don't rely on assumptions
One of the reasons aviation has traditionally performed so well is that it tries very hard not to rely on memory or assumption. Pilots brief one another before flights. Checklists exist because people forget things. Crew members cross-check one another because nobody is infallible. Debriefs happen because learning is too important to leave to chance.
These aren't box ticking exercises, they're deliberate attempts to create shared mental models. When they work well, they reduce the likelihood that two competent people walk away from the same task holding completely different assumptions about what has just happened. Good briefings and debriefings are about much more than communication. They're about creating alignment before small misunderstandings become significant problems.
The Alaska Airlines investigation is a reminder that highly sophisticated organisations remain vulnerable to remarkably ordinary human behaviours. Nobody needs to be complacent. Nobody needs to ignore procedures deliberately. Nobody needs to make a reckless decision. All that's required is for work to move between enough people that assumptions gradually replace certainty.
The second story is always worth finding
One of the easiest things to say after reading headlines like these is that somebody forgot to fit four bolts. That statement may even be true. It explains almost nothing.
If one individual forgot to complete a task, what conditions made that possible? How was the work documented? What inspections took place? What assumptions were made during the handover? How did the production system allow an incomplete task to become an accepted one? This sort of question improves performance because it moves beyond the final action and begins exploring the conditions that shaped it.
We move from the first story and the second story. The first story identifies the last visible mistake. The second story asks how the system created the conditions for that mistake to pass unnoticed.
The On Target questions
Every organisation has its own version of four missing bolts. They probably aren't made of titanium and they probably won't bring down an aircraft, but they exist nonetheless.
They might be assumptions made during a shift handover, an incomplete briefing before a project starts, a maintenance task everybody thinks someone else completed or a risk that gradually became accepted because nothing bad had happened before. They are the small pieces of work that quietly drift between teams until nobody is entirely certain who owns them.
High-performing organisations spend a great deal of time investing in communication, shared understanding and structured debriefs. They don't do this because people are incapable of doing their jobs. They do it because even highly competent people see the world slightly differently, and unless those differences are explored, they can slowly accumulate into something much larger than anyone intended.
The next time something goes wrong in your organisation, resist the temptation to stop at the first story. Ask yourself where ownership changed hands, what assumptions were made along the way and whether everyone involved genuinely shared the same understanding of the task. You may discover that the biggest risk wasn't the missing bolts at all.
It was the hundreds of assumptions that quietly formed around them.
Mike Mason and Sam Gladman help leaders and teams perform under pressure. Drawing on decades of experience in military aviation, Human Factors, accident investigation and organisational learning, they work with safety-critical organisations to improve decision-making, teamwork and leadership when conditions are uncertain. Through On Target Teaming, they combine practical tools, immersive simulations and real-world case studies to help teams perform at their best when it matters most.
If you'd like to learn more about how On Target can help your team, contact Mike and Sam at info@ontargetteaming.com.
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