Tag Archives: weather

Plane Narrowly Avoids Rolling into Bay

By ThinkReliability Staff

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.

Prison Bus Collides With Freight Train

By Kim Smiley

On the morning of January 14, 2015, a prison bus went off an overpass and collided with a moving freight train.  Ten were killed and five more injured.  Investigators believe the accident was weather-related.

This tragic accident can be analyzed by building a Cause Map, a visual root cause analysis.  A Cause Map visually lays out the cause-and-effect relationships to show all the causes (not just a single root cause) that contributed to an accident.  The first step in the Cause Mapping method is to determine how the incident impacted the overall organizational goals.  Typically, more than one goal needs to be considered.  Clearly the safety goal was impacted because of the deaths and injuries.  The property goal is impacted because of the damage to both the bus and train (two train cars carrying UPS packages were damaged).  The schedule goal is impacted because of the delays in the train schedule and the impact on vehicle traffic.

The Cause Map itself is built by starting at one of the impacted goals and asking “why” questions. So why were there fatalities and injuries?  This occurred because there were 15 people on a bus and the bus collided with a train.  The bus was traveling between two prison facilities and drove over an overpass.  While on the overpass, the bus hit a patch of ice and slid off the road, falling onto a moving freight train that was passing under the roadway.  No one onboard the train was injured and the train did not derail, but it was significantly damaged.  The bus was severely damaged.

The prisoners onboard the bus were not wearing seat belts, as is typical on many buses.  They were also handcuffed together, although it’s difficult to say how much this contributed to the injuries and fatalities.

Useful solutions to prevent these types of accidents can be tricky.  The prison system may want to review how they evaluate road conditions prior to transporting prisoners.  This accident occurred early in the morning and waiting until later in the day when temperatures had increased may have reduced the risk of a bus accident.  Transportation officials may also want to look at how roads, especially overpasses, are treated in freezing weather to see if additional efforts are warranted.

To view a high level Cause Map of this accident, click on “Download PDF” above.

You can also read our previous blogs to learn more about other train collisions:

Freight Trains Collide Head-on in Arkansas

Freight Train Carrying Crude Oil Explodes After Colliding with Another

“Ghost Train” Causes Head-on Collision in Chicago

Deadly Train Collision in Poland

Bad Weather Believed to Have Brought Down AirAsia Flight QZ8501

By ThinkReliability Staff

AirAsia flight QZ8501, and the 162 people on-board, was lost on December 28, 2014 while flying through high-altitude thunderstorms. Because of a delay in finding the plane and continuing bad weather in the area, the black box, which contains data that will give investigators more detail on why the plane went down, has not yet been recovered. Even without the black box’s data, experts believe that the terrible weather in the area was a likely cause of the crash.

“From our data it looks like the last location of the plane had very bad weather and it was the biggest factor in behind the crash. These icy conditions can stall the engines of the plane and freeze and damage the plane’s machinery,” says Edvin Aldrian, the head of Research at an Indonesian weather agency. Beyond the icing of engines, there are other theories on how weather-related issue may have brought down the plane.

Early speculation was that the plane was struck by lighting; while it may have been struck by lightning, experts say it’s unlikely it would have brought the plane down, because modern planes are fairly well-equipped to deal with direct lightning strikes. High levels of turbulence can also result in stalling due to a loss of airflow over the wings. There are also some who believe the plane (an Airbus A320) may have been pushed into a vertical climb past the limit for safe operation (to escape the weather) which resulted in a stall.

While the actual mechanism of how the weather (or an unrelated issue) brought the plane down is still to be determined, aviation safety organizations are already implementing some interventions to increase the safety of air travel in the area based on some specific areas of concern. (These areas of concern can be viewed visually in a Cause Map, or visual root cause analysis, by clicking on “Download PDF” above.)

AirAsia pilots relied on “self-briefings” regarding the weather. Pilots in other locations have expressed concern about the adequacy of weather information pilots obtain using this method. Direct pilot briefings with dispatchers based on detailed weather reporting are recommended to ensure that pilots have the information they need to safely traverse areas of poor weather (or stay out of them altogether).

Heavy air traffic in the area delayed approval to climb out of storm. At 6:12 local time the flight crew requested to climb to higher altitude to attempt to escape the storm. Air traffic control did not attempt to respond to the plane until 6:17, at which point it could no longer be contacted. Air traffic in the area was heavy, possibly because:

The plane did not have permission to fly the route it was on. AirAsia was licensed to fly the route it was taking at the time of the crash four days a week, but not the day of the crash. The takeoff airport used incorrect information in allowing the plane to take off in the first place (and the airline certainly used incorrect information in trying to fly the route as well). The selection of the route has been determined not to be a factor in the crash, but it certainly may have resulted in the overcrowding that led to the delayed response from air traffic control. It also resulted in the airline’s flights on that route being suspended.

It took almost three days to find the plane. The delay is renewing calls for universal tracking of aircraft or real-time streaming of flight data that were initially raised after the loss of Malaysia Airline flight MH370, which is still missing ten months after losing radar contact. (See our previous blog on the difficulties finding it.) Not only would this reduce the suffering of families while waiting to hear their loved ones’ fates, it would reduce resources required to find lost aircraft and, in cases where survival is possible, increase the chance of survival of those on the plane.