What Went Wrong to Swissair Flight 111 - Research Paper Example

Fire in the cockpit Lecturer What went wrong to Swissair flight 111? Introduction The aviation industry remains to be one of the most sensitive industries across the world. Most incidents and accidents involving an aircraft tend to cause enormous damage and a high number of fatalities. However, air traffic is still the safest means of transport globally. Due to its sensitive nature, aviation accidents allow for safety improvements to be made to this industry, and this calls for speedy and thorough investigations. Such investigations establish the cause of the accidents and measures that can be taken to prevent similar or related occurrences in future. This paper delves into one of the biggest aviation accidents in history; the crash of Swissair Flight 111. This accident brought to fore one of the most common causes of aviation accidents- structural and design problems. The insulating material used to cover fiberglass insulation had propagated a fire that was started above the cockpit ceiling by an arcing event. Although aircraft insulation blankets help in protecting passengers and crew against noise and frigid temperatures at high altitudes, the materials used should meet the Federal Aviation Authority (FAA) flammability test requirements. The accident Swissair Flight 111 was en route from New York, United States of America to Geneva, Switzerland on 2 September 1998. There were 229 souls on board (National Geographic, 2014). However, approximately 53 minutes into the flight, while the plane was flying 33000 feet, the crew members began to smell something unusual in the cockpit. The smell came from an area right above them. Almost at the same time, the pilots noticed a small amount of smoke filing the cockpit. The pilots started to investigate exactly where the smoke came from (Carley, 1998). After a while, they noticed that what was initially seen as the source could no longer be seen, and they stopped the investigation. Based on their experience and perception, they concluded that the smell and smoke was as a result of the air conditioning system in the pane. Although the smoke had disappeared, the pilots decided that it was necessary to land and have the plane checked before continuing with the flight. At first, they wanted to turn to Boston, but the air traffic controller advised them to land at Halifax, Canada (National Geographic, 2014). The crew also requested the air traffic controller at Halifax that they needed to dump fuel, and the plane was diverted to St. Margaret’s Bay where the fuel could be dumped. The crew started to prepare for an emergency landing, and this involved undertaking the procedure for dealing with smoke of unknown origin (Public Broadcasting Service, 2004). Among other things, the crew decided to cut unnecessary power to the cabin. As the crew continued with its preparations, they were unaware of the fire that was rapidly spreading above them in the cockpit ceiling. When the aircraft was at least six minutes from the airport, the master warning tone began to sound, indicating that multiple aircraft systems were failing. The crew declared an emergency and requested that they had to land immediately. Communication with the plane was lost, and only radar was in use. Moments later, the plane became uncontrollable and began to turn away from the airport into the open ocean. It crashed, killing all the 229 people on board. The plane was completely destroyed. The investigation The Transportation Safety Board of Canada (TSB) launched an investigation, and this was led by Larry Vance. In order to recover the wreckage from the sea, more than twenty agencies were involved in the operation. Even before the investigation started, the team knew that the plane had been on fire and the pilots had tried to fight the fire. The investigators were thus interested in understanding how the fire started, how it spread and how it eventually disabled the plane leading to the crash. The wreckage recovery operations led to the recovering of nearly 98% of the airplane’s structural weight (Transportation Safety Board of Canada, 2003). The wreckage was taken to Shearwater, Nova Scotia, in Canada where it was examined. This involved a careful reconstruction of the plane using the wreckage obtained. More than 350 people were involved in the sorting, examination and investigation of the wreckage. Based on the reconstruction of the plane, the investigating team concluded that the fire started from the space above the cockpit ceiling. Much of the investigation focused on the wires recovered (Public Broadcasting Service, 2004). This was done to identify areas where electrical arcing could have happened on the copper wires. Based on the conditions of the wires, the investigators were able to tell boundaries of the fire. The wire examination helped to explain why most of the aircraft systems were lost. Most of the plane’s 250km of wire was recovered. A careful examination of the wires revealed that some segments of the copper wires exhibited signs of electrical arcing. The investigators were interested in finding wires that showed signs of arcing because this was the likely cause of the fire (TSB, 2003). An arcing occurs when a powered conductor gets into contact with another conductor that acts as an earth, and this produces sparks that can ignite a fire. One piece of the wire was found to have arc two arc sites, and these arc sites were determined by the investigation team to be located just above the cockpit. This was the region where the fire started. The investigators thus concluded that the arcing events on the piece of wire started the fire. There were no smoke detectors located in this region, and therefore pilots were unaware of the fire that had been started. In addition, the investigation team discovered that the aircraft did not have good Circuit Breakers (CB) that could help in against the various forms of arcing events (TSB, 2003). This explains why the two events were able to produce sparks which ignited the flammable materials. The second important question investigators wanted to answer was how the fire had propagated. Based on the wreckage and materials found after the crash, the investigators quickly realized that the plane had metalized Mylar, which was highly flammable. This was proven during an experiment conducted by the investigation g team on the material. Although the FAA requires that all material should be tested before being used in aircraft construction, metalized Mylar was still being used (TSB, 2003). This is because the material had passed all the FAA flammability tests, although previous events had suggested that this material was dangerous. In all aircraft, acoustic insulation materials are used extensively throughout the fuselage to maintain comfortable temperatures in the cabin. The most common choice for this insulation is insulation blanket. These blankets are usually installed in the area around the conditioning ducts. The choice of the cover material for the blankets is critical, and hence a number of factors are considered before making the selection. In the present aircraft, polyethylene terephthalate (PET) (or commonly referred to as Mylar) and Polyvinyl fluoride PVF were used as the cover materials (TSB, 2003). Based on the FAA tests for certification applied at the time, these materials were permitted for use in an aircraft. However, these tests were insufficient, and the danger of using these materials in an aircraft was not fully understood. These materials were actually highly flammable, and previous events involving different aircraft had suggested that these materials were dangerous for use in an aircraft. The fire was further propagated by the presence of additional flammable material available in the forward cabin ceiling (Steenblik, 2003). The fire moved back into this area through a cutout located at the top of the cockpit rear wall. This cutout was filled with some kind of foam material that was highly flammable. Investigators also concluded that since the pilots were busy following the checklist procedure for smoke of unknown origin, the conditions in the cockpit deteriorated further. In addition, when the pilots turned off the air conditioning, there was a reversal of air flow in the cabin attic area and the fire started moving forwards towards the cockpit. Initially, when the air conditioning was on, it helped draw the fire away from the cockpit. This explains why the flight data recorder (FDR) started to record multiple failures of aircraft systems (Steenblik, 2003) The failure of the systems was the contributing factor to the disabling of the plane. This started by the disconnecting of the autopilot, which indicated to the pilots that there was a problem with the aircraft. The fire, which started to flow towards the cockpit area after the air conditioning was switched off, attacked the avionics compartment (TSB, 2003). This led to massive failures of systems, which made it impossible for the pilots to have any form of control of the plane. In addition, the conditions in the cockpit started to deteriorate, and the display systems stopped functioning. There was massive heat in the cockpit and the amount of smoke kept increasing (TSB, 2003). This made the work for the pilots even more difficult, especially considering that the autopilot had been lost. The plane thus started flying off course uncontrollably. Dealing with multiple abnormal tasks in the cockpit under such poor conditions led to the loss of control of the aircraft, and as a result, the plane plunged into the sea. The investigators were thus able to establish the cause of the fire, its propagation and how it had led to massive failures and eventual disabling of the aircraft. Based on the investigation report, the pilots were not to be blamed for the accident. The investigation was one of longest in the aviation history, lasting four and half years. The TSB came up with several recommendations relating to materials uses in aircraft, wiring systems and the capture of flight data, in addition, recommendations were made on the improvement of fire fighting and fire detection systems and procedures used in aircraft. Recommendations /Outcomes Based on the findings of the investigation, the team made several recommendations that have been adopted by the FAA and other aviation regulators around the world. First, the FAA reviewed the wiring used in all MD-11 aircraft. Specifically, the FAA wanted inspections to be carried out to determine if there were discrepancies that could lead to electrical arcing. A number of MD-11s were inspected, and the FAA came up with a comprehensive plan that was to be used in correcting the wiring problems in MD-11s. The wiring correction plan was launched in two phases (Federal Aviation Administration, 2003 (a)). In the first phase, focus was on the areas that had been highlighted by the TSB investigation team. The second phase involved corrective action packages, and this was developed through the collaboration with Boeing. In 20001, the FAA developed the Enhanced Airworthiness Program for Airplane Systems (EAPAS) in order to enhance the awareness of the wiring system degradation. In addition, this program aims at implementing the improvement procedures for aircraft wiring and ensures that such information is well spread throughout the aviation industry (FAA, 2003 (a)). Among other things, the EAPAs program recommended new training for FAA inspectors and engineers (FAA, 2003 (a). Secondly, the FAA also put measures in place to remove dangerous insulation materials that were being used in aircraft. The FAA proposed that the MPET-covered insulation blankest should be removed from all aircraft registered in the United States. All insulation blankets covered in the metalized Mylar were supposed to be removed by the operators by May of 2005 (Federal Aviation Administration, 2005 (b)). The FAA also improved its flammability tests for the acoustic insulation materials used in aircraft. In regard to the in-flight entertainment systems, the FAA identified unsafe conditions associated with such systems, and measure were put in place to initiate changes to the passenger flight entertainment systems. Thirdly, the FAA made improvements in the in-flight fire fighting procedures. This was done with the aim of reducing the time required to assess and gain full control of a similar situation as the one witnessed in Flight 111. The FAA has put measures in place that allow for easy access to the most hidden areas of an aircraft for purposes of effective firefighting. The FAA has also improved the firefighting procedures by requiring operators to develop and use effective fire and smoke detection systems. In addition, aircraft are required to be fitted with highly fire resistant materials for the interior. The FAA also implements the International Civil Aviation Organization (ICAO) procedures on the protection smoke in flight deck, the extraction of smoke in the cabin and suppression of fire in the cargo compartment (FAA, 2005 (b)). These measures are aimed at increasing the chances of early detection and suppression of fires before they cause extensive damage. In general, most of the recommendations of the investigating team have been adopted by various regulators and agencies across the world. The full adoption and implementation of these recommendations might take a long time, but most of them have been implemented. Conclusions The crash of Swissair Flight 111 on 2 September 1998 provided major lessons for the aviation industry. The aircraft certification standards for materials were found to be inadequate since they allowed for highly flammable materials to be used in the aircraft. These materials propagated the fire that severely damaged the aircraft system. There were also other materials that were found to be flammable which further contributed to the fire. These materials include foams, adhesives and splicing tapes. The aircraft lacked proper smoke detection and fire suppression devices in the cockpit area where the fire started. This meant that the pilots were faced with extremely difficult circumstances in identifying the fire, and this contributed to the propagation of the fire. They were merely relying on their senses of smell and sight to deal with the crisis. The aircraft did not have proper circuit breakers that cold effectively protect against all forms of wire arcing events. It was an arcing event that produced the spark that ignited the flammable materials. Had there been an effective circuit breaker, the ignition wouldn’t have occurred in the first place. The most significant contribution was a reevaluation of the materials used in aircraft interiors, and an improvement of the methods used in testing of these materials. The metalized Mylar used in this aircraft was the major cause of the fire which eventually led to the disabling of the aircraft. For this reason, airline regulators and operators have become more cautious of the materials used in the construction and furnishing of aircraft. The biggest lesson from this incident is that while aircraft use electronics and wiring systems in their design, the insulation blankets need to pass the flammability test to avoid any chance of a fire occurring. In 2001, the FAA banned the use of insulation blankets that fail to meet the new flammability requirements, AN-26. References Carley, W. (1998). Swissair 111 Crash Spurs Debate On Following Cockpit Procedure. Wall Street Journal. Retrieved from http://online.wsj.com/articles/SB913760693252632000 Federal Aviation Administration (2003) (a). Fact Sheet – FAA Actions on Aircraft Wiring and Insulation. Retrieved 4 November 2014, from http://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=6248 Federal Aviation Administration,. (2005) (b). Press Release – FAA Proposes Removal or Modification of Aircraft Insulation Blankets. Retrieved 4 November 2014, from http://www.faa.gov/news/press_releases/news_story.cfm?newsId=5743 National Geographic,. (2014). Air Crash Investigation: Swissair Flight 111 Fire In The Cockpit. Retrieved from https://www.youtube.com/watch?v=fiy8ttJSJDI Public Broadcasting Service (PBS) (2004). Crash of Flight 111. Retrieved from http://www.pbs.org/wgbh/nova/aircrash/dissection.html Steenblik, J. (2003). Swissair 111: A Needle Found in a Haystack. Air Line Pilot, p.12. Retrieved from https://www.alpa.org/portals/alpa/magazine/2003/Aug2003_Swissair111.htm Transportation Safety Board of Canada (TSB),. (2003). Aviation Investigation Report In-Flight Fire Leading to Collision with Water Swissair Transport Limited McDonnell Douglas MD-11 HB-IWF Peggy’s Cove, Nova Scotia 5 nm SW 2 September 1998. Canada: Transportation Safety Board of Canada. Read More