Monthly Archives: September 2015

Root Cause Analysis - Incident Investigation

Volkswagen admits to use of a ‘defeat device’

By Kim Smiley

The automotive industry was recently rocked by Volkswagen’s acknowledgement that the company knowingly cheated on emissions testing of several models of 4-cylinder diesel cars starting in 2009.  The diesel cars in question include software “defeat devices” that turn on full emissions control only during emissions testing.  Full emissions control is not activated during normal driving conditions and the cars have been shown to emit as much as 40 times the allowable pollution.   Customers are understandably outraged, especially since many of them purchased a “clean diesel” car in an effort to be greener.

The investigation into this issue is ongoing and many details aren’t known yet, but an initial Cause Map, a visual format for performing a root cause analysis, can be created to document and analyze what is known.  The first step in the Cause Mapping process is to fill in a Problem Outline with the basic background information and how the issue impacts the overall organizational goals.  The “defeat device” issue is a complex problem and impacts many different organizational goals.  The increased emissions obviously impacts the environmental goal and the potential health impacts of those emissions is an impact to the safety goal.  Some of the specific details are still unknown, like the exact amount of the fines the company will face, but we can safely assume the company will be paying significant fines (on the order of billions) as a result of this blatant violation of the law.  The Volkswagen stock price also took a major hit and dropped more than 20 percent following the announcement of the diesel emissions issues.  It is difficult to quantify how much the loss of consumer confidence will impact the company long-term, but being perceived as a dishonest company by many will certainly impact their sales.   A large recall that will be both time-consuming and costly is also in Volkswagen’s future.  Depending on the investigation findings, there is also the potential for criminal prosecution because of the intentional nature of this issue.

Once the overall impacts to the goals are defined, the actual Cause Map can be built by asking “why” questions.  So why did these cars include “defeat devices” to cheat on emissions tests?  The simple answer is increased profits.  Designing cars that appeared to have much lower emissions than they did in reality allowed Volkswagen to market a car that was more desirable. Car design has always included a trade-off between emissions and performance.  Detailed information hasn’t been released yet, but it is likely that the car had improved fuel economy and improved driving performance during normal driving conditions when full emissions control wasn’t activated. Whoever was involved in the design of the “defeat device” also likely assumed the deception would never be discovered, which raises concern about how emissions testing is performed.

The design of the “defeat device” is believed to work by taking advantage of unique conditions that exist during emissions testing. During normal driving, the steering column moves as the driver steers the car, but during emissions testing the wheels rotate, but the steering column doesn’t move.  The “defeat device” software appears to have monitored the steering column and wheels to sense when the conditions indicated an emissions test was occurring.  When the wheels turned without corresponding steering wheel motion, the software turned the catalytic scrubber up to full power, reducing emissions and allowing the car to pass emissions tests. Details on how the “defeat device” was developed and approved for inclusion in the design haven’t been released, but hopefully the investigation into this issue will be insightful and help understand exactly how something this over the line occurred.

Only time will tell exactly how this issue impacts the overall health of the Volkswagen company, but the short-term effects are likely to be severe.  This issue may also have long-reaching impacts on the diesel market as consumer confidence in the technology is shaken.

To view an Outline and initial Cause Map of this issue, click on “Download PDF” above.

Uncategorized

Runway Fire Forces Evacuation of Airplane

By ThinkReliability Staff

On September 8, 2015, an airplane caught fire during take-off from an airport in Las Vegas, Nevada. The pilot was able to stop the plane, reportedly in just 9 seconds after becoming aware of the fire. The crew then evacuated the 157 passengers, 27 of whom received minor injuries as a result of the evacuation by slide. Although the National Transportation Safety Board (NTSB) investigation is ongoing, information that is known, as well as potential causes that are under consideration, can be diagrammed in a Cause Map, or visual root cause analysis.

The first step of Cause Mapping is to define the problem by completing a problem outline. The problem outline captures the background information (what, when and where) of the problem, as well as the impact to the goals. In this case, the safety goal is impacted due to the passenger injuries. The evacuation of the airplane impacts the customer service goal. The NTSB investigation impacts the regulatory goal. The schedule goal is impacted by a temporary delay of flights in the area, and the property goal is impacted by the significant damage to the plane. The rescue, response and investigation is an impact to the labor goal.

The Cause Map is built by beginning with one of the impacted goals and asking “Why” questions to develop the cause-and-effect relationships that led to an issue.   In this case, the injuries were due to evacuation by slide (primarily abrasions, though some sources also said there were some injuries from smoke inhalation). These injuries were caused by the evacuation of the airplane. The airplane was evacuated due to an extensive fire. Another cause leading to the evacuation was that take-off was aborted.

The fact that take-off was able to be aborted, for which the pilot has been hailed as a hero, is actually a positive cause. Had the take-off been unable to be aborted, the result would likely have been far worse. In the case of the Concorde accident, a piece of debris on the runway ruptured a tire, which caused damage to the fuel tank, leading to a fire after the point where take-off could be aborted. Instead, the aircraft stalled and crashed into a hotel, killing all onboard the craft and 4 in the hotel. The pilot’s ability to quickly save the plane almost certainly saved many lives.

The fire is thought to have been initiated by an explosion in the left engine due a catastrophic uncontained explosion of the high-pressure compressor. This assessment is based on the compressor fragments that were found on the runway. This likely resulted from either a bird strike (as happened in the case of US Airways flight 1549), or a strike from other debris on the runway (as occurred with the Concorde), or fatigue failure of the engine components due to age. This is the first uncontained failure of this type of engine, so some consider fatigue failure to be less likely. (Reports of an airworthiness directive after cracks were detected in weld joints of compressors were in engines with different parts and a different compressor configuration.)

In this incident, the fire was unable to be put out without assistance from responding firefighters. This is potentially due to an ongoing leak of fuel if fuel lines were ruptured and the failure of the airplane’s fire suppression system, which reportedly deployed but did not extinguish the fire. Both the fuel lines and fire suppression system were likely damaged when the engine exploded. The engine’s outer casing is not strong enough to contain an engine explosion by design, based on the weight and cost of providing that strength.

The NTSB investigation is examining airplane parts and the flight data and cockpit voice recorders in order to provide a full accounting of what happened in the incident. Once these results are known, it will be determined whether this is considered an anomaly or whether changes to all planes using a similar design and configuration need to take action to prevent against a similar event recurring.

To view the initial investigation information on a one-page downloadable PDF, please click “Download PDF” above.

 

Root Cause Analysis - Incident Investigation

Waste Released from Gold King Mine

By Renata Martinez

On August 5, 2015 over 3 million gallons of waste was released from Gold King Mine into Cement Creek which then flowed into the Animas River. The orangish colored plume moved over 100 miles downstream from Silverton, Colorado through Durango reaching the San Juan River in New Mexico and eventually making its way to Lake Powell in Utah (although the EPA stated that the leading edge of the plume was no longer visible by the time it reached Lake Powell a week after the release occurred).

Some of the impacts were immediate.  No workers at the mine site were hurt in the incident but the collapse of the mine opening and release of water can be considered a near miss because there was potential for injuries. After the release, there were also potential health risks associated with the waste itself since it contained heavy metals.

Water sources along the river were impacted and there’s potential that local wells could be contaminated with the waste.   To mitigate the impacts, irrigation ditches that fed crops and livestock were shut down.  Additionally, the short-term impacts include closure of the Animas River for recreation (impacting tourism in Southwest Colorado) from August 5-14.

The long-term environmental impacts will be evaluated over time, but it appears that the waste may damage ecosystems in and along the plume’s path. There are ongoing investigations to assess the impact to wildlife and aquatic organisms, but so far the health effects from skin contact or incidental ingestion of contaminated river water are not considered significant.

“Based on the data we have seen so far, EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) do not anticipate adverse health effects from exposure to the metals detected in the river water samples from skin contact or incidental (unintentional) ingestion. Similarly, the risk of adverse effects to livestock that may have been exposed to metals detected in river water samples from ingestion or skin contact is low. We continue to evaluate water quality at locations impacted by the release.”

The release occurred when the EPA was working to stabilize the existing adit (a horizontal shaft into a mine which is used for access or drainage). The force of the weight of a pool of waste in the mine overcame the strength of the adit, releasing the water into the environment.  The  EPA’s scope of work at Gold King Mine also included assessing the ongoing leaks from the mine to determine if the discharge could be diverted to retention ponds at the Red and Bonita sites.

The wastewater had been building up since the adit collapsed in 1995.  There are networks and tunnels that allow water to easily flow between the estimated 22,000 mine sites in Colorado.  As water flows through the sites it reacts with pyrite and oxygen to form sulfuric acid.  When the water is not treated and it contacts (naturally occurring) minerals such as zinc, lead, cadmium, copper and aluminum and breaks down the heavy metals, leaving tailings.  The mines involved in this incident were known to have been leaking waste for years.  In the 90s, the EPA agreed to postpone adding the site to the Superfund National Priorities List (NPL), so long as progress was made to improve the water quality of the Animas River.  Water quality improved until about 2005 at which point it was re-assessed.  Again in 2008, the EPA postponed efforts to include this area on the NPL.  From the available information, it’s unclear if this area and the waste pool would have been treated if the site was on the NPL.

In response, the “EPA is working closely with first responders and local and state officials to ensure the safety of citizens to water contaminated by the spill. ” Additionally, retention ponds have been built below the mine site to treat the water and continued sampling is taking place to monitor the water.

So how do we prevent this from happening again?  Mitigation efforts to prevent the release were unsuccessful.  This may have been because the amount of water contained in the mine was underestimated.  Alternatively, if the amount of water in the mine was anticipated (and the risk more obvious) perhaps the excavation work could have been planned differently to mitigate the collapse of the tunnel.  As a local resident, I’m especially curious to learn more facts about the specific incident (how and why it occurred) and how we are going to prevent this from recurring.

The EPA has additional information available (photos, sampling data, historic mine information) for reference: http://www2.epa.gov/goldkingmine

Root Cause Analysis - Incident Investigation

Spider in air monitoring equipment causes erroneously high readings

By Kim Smiley

Smoke drifting north from wildfires in Washington state has raised concerns about air quality in Calgary, but staff decided to check an air monitoring station after it reported an alarming rating of 28 on a 1-10 scale.  What they found was a bug, or rather a spider, in the system that was causing erroneously high readings.

The air monitoring station measures the amount of particulate matter in air by shining a beam of light through a sample of air.  The less light that makes it through the sample, the higher the number of particulates in the sample and the worse the quality of air.  You can see the problem that would arise if the beam of light was blocked by a spider.

This example is a great reminder not to rely solely on instrument readings.  Instruments are obviously useful tools, but the output should always be run through the common sense check.  Does it make sense that the air quality would be so far off the scale?  If there is any question about the accuracy of readings, the instrument should probably be checked because the unexpected sometimes happens.

In this case, inaccurate readings of 10+ were reported by both Environment Canada and Alberta Environment before the issue was discovered and the air quality rating was adjusted down to a 4.  Ideally, the inaccurate readings would have been identified prior to posting potentially alarming information on public websites.  The timing of the spider’s visit was unfortunate because it coincided with smoky conditions that made the problem more difficult to identify, but extremely high readings should be verified before making them public if at all possible.

Adding an additional verification step when there are very high readings prior to publicly posting the information could be a potential solution to reduce the risk of a similar problem recurring.  A second air monitoring station could be added to create a built-in double check because an error would be more obvious if the monitoring stations didn’t have similar readings.

Depending on how often insects and spiders crawl into the air monitoring equipment, the equipment itself could be modified to reduce the risk of a similar problem recurring in the future.

To view a Cause Map, a visual root cause analysis, of this issue, click on “Download PDF” above.