Passengers landing at LaGuardia airport in New York amidst a heavy snowfall on March 5, 2015, were stunned (and 23 suffered minor injuries) when their plane overran the runway and approached Flushing Bay. The National Transportation Safety Board (NTSB) is currently investigating the accident to determine not only what went wrong in this particular case, but what standards can be implemented to reduce the risk of runway overruns in the future.
Says Steven Wallace, the former director of the FAA’s accident investigations office (2000-2008), “Runway overruns are the accident that never goes away. There has been a huge emphasis on runway safety and different improvements, but landing too long and too fast can result in an overrun.” Runway overruns are the most frequent type of accident (there are about 30 runway overruns due to wet or icy runways across the globe every year), and runway overruns are the primary cause of major damage to airliners.
Currently, the NTSB is collecting data (evidence) to aid in its investigation of the accident. The plane is being physically examined, and the crew is being interviewed. The data recorders on the flight are being downloaded and analyzed. While little information is able to be verified or ruled out at this point, there is still value in organizing the questions related to the investigation in a logical way.
We can do this using the Cause Mapping method of root cause analysis, which organizes cause-and-effect relationships related to an incident. We begin by capturing the impact to an organization’s goals. In this case, 23 minor passenger injuries were reported, an impact to the safety goal. There was a fuel leak of unknown quantity, which impacts the environmental goal. Customer service was impacted due to a scary landing and evacuation from the aircraft via slides. Air traffic at LaGuardia was shut down for 3 hours, impacting the production goal. Both the airplane and the airport perimeter fence suffered major damage, which impacts the property/equipment goal. The labor goal was also impacted due to the response and ongoing investigation.
By beginning with an impacted goal and asking “why” questions, we can begin to diagram the potential causes that may have resulted in an incident. Potential causes are causes without evidence. If evidence is obtained that supports a cause, it becomes a cause and it is no longer followed by a question mark. If evidence rules out a cause, it can be crossed out but left on the Cause Map. This reduces uncertainty as to whether a potential cause has been considered and ruled out, or not considered at all.
In this case, the NTSB will be looking into runway conditions, landing procedures, and the condition of the plane. According to the airport, the runway was cleared within a few minutes of the plane landing, although the crew has said it appeared all white during landing. The National Weather Service reported 7″ of snow in the New York area on the day of the overrun. Procedures for closing runways or aborting landings are also being considered. Just prior to the landing, other pilots who had recently landed reported braking conditions as good.
The crew has also reported that although the auto brakes were set to max, they did not feel any deceleration. The entire braking system will be investigated to determine if equipment failure was involved in the accident. (Previous overruns have been due to brake system failures or the failure of reverse thrust from one of the engines, causing the plane to veer.) The pilot also reported the automatic spoiler did not deploy, but they were deployed manually.
Also being investigated are the landing speed and position, though there is no evidence to suggest that there was any issue with crew performance. As more information is released, it can be added to the investigation. When the cause-and-effect relationships are better determined, the NTSB can begin looking at recommendations to reduce future runway overruns.