Monthly Archives: July 2012

Root Cause Analysis - Incident Investigation

Hindenburg Crash – May 6, 1937

By ThinkReliability Staff

On May 6th, 1937, the Hindenburg burst into flames over the Lakehurst, NJ Naval Base, after completing a successful trip across the Atlantic.  35 of the 97 passengers (and one of the ground crew) were killed.  The Hindenburg itself was a total loss, and the popularity of airships never recovered after the accident.

The loss of 36 lives and the loss of the Hindenburg were both caused by the fire aboard. The loss of popularity of airships was caused by both the loss of the Hindenburg, and by the loss of lives.  The next question to ask is “Why did the fire occur?”

For the Hindenburg, this is where things start to get interesting.  There are three separate theories about why the fire started.  There are people who believe very strongly in each.   Luckily for us, the beauty of the Cause Map form of a root cause analysis is that we can use it even if we haven’t determined which theory is correct.

The first theory is that the fire started from sabotage.  Because the Hindenburg was frequently used as a Nazi propaganda tool, some thought it was almost too easy of a target for sabotage from anti-Nazi activists (who included in their number the designer of Hindenburg, Dr. Hugo Eckener.)  There was even a “suspicious” character who survived the crash, a German acrobat living in America.  However, eventually the FBI dismissed the idea of sabotage as a “red herring.”

Another theory is that the fire began when static electricity ignited the flammable cover of the airship.  The major proponent of this theory, Dr. Addison Bain, has run tests on pieces of the Hindenburg cover preserved from the wreck site.  (This was not until 1994.)  He has also found supporting evidence from historic records of the Zeppelin company.

The other theory is that static electricity ignited a flammable hydrogen-oxygen mixture.  This was the original cause attributed to the disaster by the U.S. Department of Commerce’s root cause analysis investigation after the crash.  There are also people who claim that Dr. Bain’s theory is physically impossible, and do not specifically champion a cause, but treat this one as the most likely.

Note that we’re not espousing a theory – we are just recording all of the possibilities.  Once we have done that, the Cause Map allows us to find solutions for any potential causes.  Once we have all the theories mapped out, we can use the Cause mMp as a resource to determine the solutions that are most helpful, or continue our root cause analysis investigation to determine which causes are most likely.

Root Cause Analysis - Incident Investigation

Navy Jet Crashes into Apartment Building

By Kim Smiley

On April 6, 2012, a Navy F-18 jet crashed into an apartment building in Virginia Beach, Virginia. Significant damage was done to the apartment building and the jet was destroyed, but amazingly no one was seriously injured or killed.

This incident can be analyzed by building a Cause Map, an intuitive, visual format for performing a root cause analysis.  The first step when building a Cause Map is to determine how the incident affected the organizational goals.  The impacts to the organizational goals are recorded in the Outline which also documents the background information of the incident.  In this example, the safety goal was obviously impacted since there was potential for serious injuries.  The property goal was also impacted because the jet was destroyed and the apartment building suffered extensive damage.

Once the Outline is complete, “why” questions are asked to determine what factors contributed to the incident.  In this example, there was potential for injuries because a jet hit an apartment building.  This occurred because the jet was flying near the residential area and the jet was unable to complete its attempted take off.  The pilots could have been injured had they not been able to safety eject before the crash and there was potential for people on the ground to be injured since the jet crashed into a residential area. The jet crashed because it experienced a dual engine failure.  The investigation into this crash determined that that both engines failed for two separate, unrelated reasons.

The right engine failed because of a catastrophic failure of the engine compressor when it ingested flammable liquid that was ignited.  The left engine afterburner failed to light. Investigators believe that an electrical component failed, but the damage to the left engine was too severe for a conclusive determination of what exactly occurred.   According to the Navy, this is the first unrelated dual engine failure of a F-18.

The Navy plans to update procedures to incorporate the possibilities of this type of incident.

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

Root Cause Analysis - Incident Investigation

Loss of Firefighting Plane Affects Firefighting Efforts

By ThinkReliability Staff

Wildfires in the Rocky Mountain region have been plaguing the nation for weeks.  The firefighting mission took a severe hit when a C-130 that was dropping flame retardant on the fire crashed on the evening of July 1, 2012, killing four of six crewmembers and injuring the other two.  As a result of the crash, the Air Force grounded other C-130s for two days, increasing the work for firefighters on the ground.

Although the Air Force has not released details of what exactly resulted in the plane crash, we can look at the information we do have available in a visual root cause analysis or Cause Map.  We begin by determining which of the organization’s goals were impacted in the Outline.  First, because of the deaths of the crewmembers, the safety goal was impacted.  The environmental and customer service goals were impacted because of the decreased ability to fight wildfires.  The schedule goal was impacted because other C-130s were grounded for two days.  The property goal was impacted because of the damage to the plane, and the labor goal was impacted due to the increased difficulty for remaining firefighters in fighting the fire.

Once we have determined these impacts to the goals, we can begin asking “Why” questions to draw out the cause-and-effect relationships that led to the impacted goals.  The safety, and other goals, were impacted due to the plane crash.  Again, although the Air Force has not released details of its ongoing investigation, it is believed that  downdraft (caused by the same high winds in the area that are helping to keep the wildfires travel) may have contributed to the crash.  An additional contributor is the fact that the plane was likely traveling at extremely low altitude, which allowed the plane to perform its task to help fight wildfires.  Lastly, it is possible that the heavy demands placed on the plane due to the extent of the fires may have contributed to the incident.  If, during the course of the investigation, it is determined that one of these causes was not related to the plane crash, the causes can be crossed out, but left on the map.  Evidence that shows that this cause did not result in the incident should be placed under the box.  This allows us to keep a complete record of which causes were considered.

Once the causes related to the incident have been placed on the map, solutions to mitigate the risk of this type of incident from happening again can be brainstormed and implemented.

To view the Outline and Cause Map, please click “Download PDF” above

Root Cause Analysis - Incident Investigation

Lead Poisoning Threatens California Condor Population

By Kim Smiley

A recent study found that lead poisoning remains a significant hurdle to the recovery of the California condor population, one of the world’s most endangered species.  Scientists reviewed blood samples taken from wild California condors between 1997 and 2010 and found that many birds have dangerously high levels of lead in their bodies.  Nearly half of the birds had lead levels that were high enough that they could have died without treatment.

This issue can be analyzed by building a Cause Map, a visual root cause analysis. The first step in beginning a Cause Map is to determine the impact to the overall organization goals.  In this example, the environmental goal is impacted because an endangered species is threatened.  To continue building the Cause Map, “why” questions are asked and the answers are added to the Cause Map to show the cause-and-effect relationships between the things that contributed to the issue.  To view a high level Cause Map of this issue, click “Download PDF” above.

In the case of California condors, the species is threatened because the birds are ingesting lead and it’s dangerous.  Lead is dangerous because it is a poison that can cause illness or death.  The birds are ingesting lead because they eat a large number of animals and some of the animals contain lead.

There is lead in some of the animals because California condors will eat gut piles and carcasses left behind by hunters and these animals may contain fragments from lead bullets.  Additional causes are the fact that lead bullets are very common and that hunting is allowed in condor country.  This is caused in part because condors have large habitats because of their large range.  Condors are huge birds with wingspans of nearly 10 feet and they must travel long distances to find the large amount of food they require.

Determining the best way to prevent lead poisoning in condors is a difficult question for scientists.  Part of the problem is that a very small amount of lead can cause dangerous lead levels in a condor.  A single bullet fragment can be deadly. The short term solution is to treat the birds for lead poisoning by feeding them calcium-based drugs that bind with lead and remove it from the birds. One solution that has been tried is a California law banning lead bullets in the areas populated by condors, but the study found that it has had little impact in lead levels.  The issue of how to deal with the California condor lead poisoning issue without extensive ongoing human intervention and medical treatment remains open.