Two planes came within seconds of a collision on July 31, 2012 when both were directed to the same airspace by controllers. Although no incident occurred, such near misses should be investigated thoroughly to prevent incidents in the future.
We can perform a root cause analysis of this incident in visual Cause Mapping form. We begin with the impacts to the goals. In the case of a near-miss like this one, some of the impacts to the goals will be hypothetical, based on the potential of the incident actually occurring. For example, the safety goal is impacted because of the potential of death or injury to the passengers and crew on the planes. The property goal is also impacted due to the potential of damage to the planes. Even though this incident was considered a near-miss, there were some actual impacts to the goals, such as the delay in landing of the inbound plane, which can be considered an impact to the customer service, schedule, and labor goal.
Once we have determined the impacts to the goals, we can begin the analysis by asking “why” questions. In this case, the safety and property goals were impacted due to the potential collision of two planes. These planes could have collided because they were on a collision course. One plane was taking off directly towards another plane that was trying to land. The landing plane was landing in the opposite direction as usual (from the South instead of from the North) in order to avoid high winds from an incoming storm. The plane taking off was cleared to take off towards the incoming plane (towards the South) by a different controller who was unaware that incoming planes were coming in from a different direction. Communication of the change in incoming flights was not made to all controllers in the area and, although no details are available, it appears that the procedure used by the controllers when changing the flow towards the airport was inadequate.
There are thousands of recorded errors by air traffic controllers every year, and Reagan National (where this incident occurred) has had some particularly high-profile incidents, such as when a controller fell asleep (see previous blog), involving air traffic controllers. On August 10, 2012, two aircraft clipped each other at another Washington, DC area airport, although it is unclear if controllers were involved. (See the article here.) A congressional and FAA investigation is underway, and will hopefully address some needed improvements in air safety.
To view the Outline and Cause Map, please click “Download PDF” above.