After the January 29, 2025, mid-air collision over Reagan National Airport (DCA) of a military helicopter and American Airlines Flight 5342, the National Transportation Safety Board (NTSB) reconstructed the flight paths, analyzed the altitude data, examined the communication records, and mapped the narrow vertical separation window between Helicopter Route 4 and the Runway 33 approach path. What they found was a system operating with very little margin.
Now that the investigation is complete, we can ask a different question: How much of what investigators found could have been discovered before the collision?
Between October 2021 and December 2024, the Aviation Safety Information Analysis and Sharing program recorded 15,214 close proximity events between helicopters and commercial aircraft near DCA (instances where lateral separation dropped below one nautical mile and vertical separation below 400 feet). Of those, 85 were even higher risk with lateral separation under 1,500 feet and vertical separation under 200 feet.
The same system had been producing close-proximity events that triggered warnings for air traffic controllers and pilots repeatedly in the three years before the accident.
A database of 15,214 events can tell you there is a pattern. It cannot tell you the cause-and-effect relationships within any one of them.
This is the difference between tracking incidents and investigating them. Tracking looks across a population of incidents. Investigation looks closely at one specific incident to understand exactly what happened, why it happened, and what specific solutions can prevent it from happening again. If you are dealing with recurring incidents in your organization, read our guide for what you should do first.
DCA Near Miss 6-Why Cause Map™ Diagram
The operational conditions that made the January 29th collision possible—the 35- to 75-foot vertical separation where military Route 4 crosses the Runway 33 approach path, the challenges of confirming altitude in that corridor at night, the reliance on visual separation—were the design of the system that allowed these individual anomalies to all align that one night (like the Swiss cheese model). Those conditions were part of the same DCA airspace system that had produced thousands of earlier close-proximity events. Thoroughly investigating one of those events could have identified many of the same causes the full investigation eventually uncovered.
The crash exposed conditions that already existed. If even one of those 85 serious close proximity events had been investigated with the rigor applied after the collision, the findings may have looked very familiar. The conditions were not new to January 29th. They were present before the collision and detectable in earlier events.
Your incidents and near misses also contain valuable insight into your operations, but you have to dig into the details. A Cause Map™ diagram helps reveal gaps in your work processes and identify where smaller problems could line up to produce a bigger incident. In the DCA case, information within those earlier near misses could have exposed the risks of operating at the upper limit of Route 4. Learn more about how you can investigate near misses.
Near-miss data is only as valuable as what you do with it. A trend can tell you where to look. It takes a thorough investigation into the underlying work processes to explain what needs to change.
The question after every near miss isn't "How close was that?" It's "What in our work processes allowed that to happen, and what would we find if we actually looked?"
For a detailed analysis of the DCA collision, including our Cause Mapping® investigation file, read our full breakdown here.