Evaluation and Mitigation of Aircraft Slide Evacuation Injuries (2008)

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53 A P P E N D I X F Study on Emergency Evacuation Challenges on Large Transport Aircraft

54 Executive Summary The purpose of this study was to investigate emergency evacuations challenges from large transport aircraft. The world’s largest commercial aircraft, the Airbus A380, is considered as a very large transport aircraft (VLTA). It will be the first full double- decker aircraft, with two independent decks connected by stairs. There have been several arguments concerning whether this aircraft will be able to evacuate passengers in a safe and efficient manner. The height of the upper deck was a main concern regarding this issue. The massive increase in passenger capacity and aircraft size are concerns to the difficulties which would be encountered in an evacuation. In order to conduct this research, a dynamic mathematical model was developed to obtain the velocity of an individual sliding down from the upper deck as a function of position on the slide. Parameters, such as the initial velocity and coefficient of friction were changed to see the effect they had on the results. A comparison was made between sliding from the upper deck slide of the A380 versus one of a B747. In addition to this, research was done to obtain information about slide emergency evacuation events from large transport aircraft currently in service, such as the Boeing B747. Part 121 and Part 129 slide emergency evacuations over a certain period of time were captured. The A380 passed the certification test in March 2006 which met a list of unique requirements for this type of aircraft and evacuation results were obtained from Airbus. Conclusions and recommendations for safer evacuations from larger transport aircraft will be made based on the results of the study. Introduction Passenger safety has always been a major concern to the traveling public and the improvement of safety procedures and equipment has been a major goal of the aviation industry and regulators alike. One major element to ensuring the safety of passengers is providing for the safe and orderly evacuation of passengers in emergency situations. To this end, several studies have been done concerning the evacuation of commercial passenger aircraft (Hynes 1999 & 2000; NTSB, 2000). As dictated by Part 25 of the Code of Federal Regulations, aircraft that have exits located more than 6 feet above the ground are required to have inflatable slides. The recent launch of very large transport aircraft has raised many questions regarding emergency evacuations. The major differences for larger aircraft, such as the Airbus A380, are associated with the configuration of the airplane such as the height of the emergency exits on the upper deck and thus the characteristics of the slides. There have been many discussions on whether this new aircraft would meet the certification requirements. The reasoning behind this would be that more injuries may occur during the evacuation test due to its special features. This paper will investigate this issue.

55 Background 1. Large Aircraft The Boeing 747, which has been in use since 1970, features a partial upper deck, but does not contain as many passengers as the A380 will on the upper deck. Today, the Boeing 747 is widely used throughout the world and is the largest passenger aircraft. The A380 will be the first fully double-deck airliner holding 555 passengers in a three- class configuration. It will be the world's largest airliner, farther beyond Boeing's 747. Figure 1 shows the dimensions of the Boeing 747 versus the Airbus A380. Figure 1: Boeing 747 versus Airbus A380 (Source: www.samtsai.com)

56 2. Emergency Evacuation Inflatable Slides As dictated by Code of Federal Regulations (14CFR & 25.810), the assisting means (which must be capable of carrying simultaneously two parallel lines of evacuees) for emergency evacuation must meet the following requirements: must be automatically deployed must be of such length after full deployment that the lower end is self- supporting on the ground and provides safe evacuation of occupants to the ground after collapse of one or more legs of the landing gear must have the capability, in 25 knot winds directed from the most critical angle, to deploy and, with the assistance of only one person, to remain usable after full deployment to evacuate occupants safely to the ground passengers and crew in the event of an emergency. The slides are stored deflated within the aircraft. Once the door opens, the slides inflate through the application of air Inflatable slides are located on commercial aircraft doors for evacuating pressure. According to Part 4.12 of the Technical Standard Order (TSO-C69c), there are inflation time requirements according to the type of exits or devices. Type I floor-level exit slides 1devices must be automatically erected in 6 seconds after actuation of the inflation has begun. Other devices must not exceed 10 seconds. There is a sequence for the slide deployment process: it starts from the opening door and ends when the slide is inflated. To start the inflation, pressured gas (3290 psi of mixed nitrogen and CO2) passes from the cylinder through the aspirators to the inflatable part of the slide. The aspirator’s flapper valve opens which draws in external air. The mix of gas under pressure and external air starts the inflation of the slide. The inflation process is completed when the slide has reached the pressure controlled by a pressure relief valve (Asse, 2003). Several tests are required for the materials to be used. Coated fabrics must have strength, adhesion, permeability, hydrolysis requirements. The inflatable fabric must be air holding, lightweight, high strength and have radiant heat requirements. It has for base a nylon cloth and is coated on both sides with polyether based polyurethane or neoprene. The sliding surface fabric does not have to be air holding. These are the sliding surface requirements: high mechanical strength both in traction and tear resistance (nylon cloth woven) high bonding and cementing properties on the inflatable structure coating electrical conductivity to eliminate static electricity build up low friction light weight and flexibility It is coated on one side with a low friction, conductive polyurethane compound on which evacuees can slide. The other slide has a silver-gray reflective compound (Escoffier, 2001). 1 Type I: Inflatable Slide

57 a. Airbus A380 Slide Characteristics Figure 2 shows the evacuation slides of the Airbus A380. The aircraft provides two independent passenger decks. There are a total of eight exits on each side of the aircraft: 5 Type A exits on the main deck and 3 Type A exits on the upper deck. The sill height 2 is 5.1 meters for the main deck versus 7.9 meters for the upper deck. The longest slide is 14.7 meters. More information about A380 slides angles and lengths can be found in Appendix A. Figure 2: Airbus A380 Emergency Evacuation Slides (Source:http://www.aviationnews.com.au) Literature Review There have been several studies and papers done on emergency evacuations of commercial aircraft. Some research has been focused on larger transport aircraft evacuation, especially with the future new largest commercial aircraft, the Airbus A380 (Verres, 2003; Jungermann, 2000 & 2001). A one year study done for the European Commission, called the Very Large Transport Aircraft (VLTA) Emergency Requirements Research Evacuation Study (Verres, 2003), was carried out to investigate evacuation challenges of future aircraft. Some people have categorized the Airbus A380 as a VLTA. This project also includes potential future designs such as blended-wing body aircraft. A computer model or software for the simulation of an evacuation as well as a double-deck large cabin simulator was used to analyze these issues. This report includes results of the first evacuation research trials of large double-deck aircraft and recommendations. Also, Helmet Jungermann discusses the issues of emergency evacuation from a double-deck aircraft in several papers (Jungermann, 2000 & 2001), of one which was 2 norm al sill height: the height of the exit sill above the ground with all aircraft landing gear extended (TSO-C69c Glossary of Term s)

58 presented at the International Aircraft Fire and Cabin Safety Research Conference in Atlantic City in 2001. He developed a model to analyze how factors such as slide design, visibility and passenger safety instruction would influence an individual’s performance and observed the reactions to different situations. He also studied the psychological effects of the upper deck height on human performance. He found out that additional research had to be done but found a difference in the hesitation time between individuals from the upper versus main deck. Problem Definition The topic of emergency evacuations from larger transport aircraft has been a major concern, especially with the future world’s largest commercial aircraft, the Airbus A380. U.S Federal Aviation Administration (FAA) certification criteria and tests are essential in evaluating the evacuation capabilities of a new aircraft. One of the final measures for an aircraft’s readiness to operate is the full-scale evacuation demonstration. In order to pass the FAA certification, an aircraft has to be evacuated under specific conditions within 90 seconds as required by Part 25 and Appendix J to Part 25 of the European Aviation Safety Agency (EASA) Joint Aviation Requirements and the U.S. Federal Aviation Regulations (FARs). The main question surrounding this aircraft was whether the evacuation would take longer and the number of injuries would be higher compared to conventional main deck evacuations. An additional concern for the A380 was the height from which the upper deck passengers would need to slide in case of an emergency. Study Objectives This study will examine the effect of the upper deck height and will look at slide emergency evacuations from larger transport aircraft. The objectives of this study are: 1) to develop a dynamic model to determine the velocity of a person during the slide 2) to analyze large transport slide emergency evacuation events - B747 events and certification test done for the Airbus A380 will be evaluated in detail. Mechanisms of injuries will be determined. 3) to identify issues regarding large aircraft slides (particularly upper deck slides) and provide recommendations, if any, to improve slide emergency evacuations for these type of aircraft Description of Model and Analysis A dynamic model has been developed based on an assumed curvilinear path with friction to calculate the velocity of a person at any given location (x,y) on the inflatable

59 3 . Figure 4: Unit normal and unit tangent vectors at point (x,y) Figure 3: Shape of Evacuation Slide from y=0 to y=-h at a distance x away from the aircraft 3 Classical Mechanics homework – B: Evacuation Slide (p.3-5) www.st-andrews.ac.uk/~ulf/cmhome.pdf y x -h The method used is to find the fastest curve between the starting point (0,0) and ending point (a,b) with friction. At each point on the curve (x,y), there is a unit normal and tangent vector. This is illustrated in the figure below. In order to find the optimal shape of the aircraft evacuation slide, the Brachistochrone method is used. This approach is done in a Classical Mechanics course The curve should be designed such that it takes the least possible time to slide from an exit at a height h down the ground at some distance x away from the aircraft slide. Several assumptions are needed to compute the velocity including: initial velocity, constant coefficient of friction, constant curvature of the slide and no deflection due to weight of individuals on the slide. The parameters required are: the total length of the slide, the initial velocity of an individual and the coefficient of friction. These parameters are changed to see the effect they have on the velocity. For this model, conservation of energy is used neglecting the air drag on the person, but accounting for friction. (Source: Haws and Kiser, 1995)

60 These unit directional vectors can be written as: j ds dy i ds dx T ˆ ˆ (unit tangent) j ds dx i ds dy N ˆ ˆ (unit normal) where s represents the arc length. The force of gravity acting in the y direction is: j mg F g ˆ Similarly, the friction force can be expressed as: T N F F g f ) ( T ds dx mg The components for the force of gravity and friction force in the tangent direction along the curve are: ds dy mg T F g T F f ds dx mg Using Newton’s first law ) ( ma F , and substituting dt dv a , we get T ds dy mg T dt dv m T ds dx mg which simplifies to ds dy g dt dv ds dx g

61 Then, using the relation: dt ds v or v dsdt , we obtain that: ds vd ds dv v vds dv dt dv )( 2 1 )/( 2 Substituting dt dv in Newton’s second law, we obtain: ds dyg ds vd )( 2 1 2 ds dxg Integrating the above equation with respect to s, we obtain: gyv 2 2 1 Cgx or ygv ( 2 1 2 Cx) It is necessary to find the constant of integration, C . Using the initial condition, at the initial point, the velocity equals the initial velocity (at point (0,0), 0vv ), therefore: Cv 0 2 1 2 0 which gives 202 1 vC Plugging the constant of integration back in the equation gives: ygv ( 2 1 2 2 02 1) vx Simplifying the above equation yields ygv (22 20) vx 2 0)(2 vxygv (1.1) Equation (1.1) is used in the program to calculate the velocity at any given point (x,y) on the curve.

62 Then, by applying Euler-Lagrange equation: 0)'( FyFy dx d , we obtain a second order differential equation. The equations obtained (Haws and Kiser, 1995) for the fastest curve with friction are: )()( cxx (1 – cos ) (1.2) and )()( cyy ( + sin ) (1.3) where: )sin()(cx and )cos1()(cy and f are determined with the ending point (a,b). The Matlab program can be found in Appendix B. 1. Discussion of Model Implementation and Assumptions These are the following known parameters: The length and height of the slide are known values. According to Part 5.5.4.3.1 of TSO-C69c, the test subjects’ clothing which contacts the device surface shall be a material with a coefficient of friction of at least 0.4 per ASTM Standard D1894-90 (typical of cotton or polyester/cotton blend). It should also be noted that according to Part 4.17 of TSO-C69c the means provides protection for an evacuee who crosses the emergency exit threshold at a horizontal velocity of 6 feet per second. Equations (1.2) and (1.3) are used to plot the shape of the curve. The coordinates for the ending point (a,b) are needed: the y-component is the height (h) from the ground to the top of the evacuation slide the x-component is unknown. When no person slides down, the evacuation slide does not bend down. According to Pythagorean

63 theorem, the x component has then a maximum value of 5 . 0 2 2 ) ( l h . Figure 5 illustrates the problem. When a person slides down, the slide bends and th e x component is therefore smaller than the maximum value. An approximation of this value will be inputted in the program and then tested and checked until the exact length of the slide is obtained. h = height to top of the slide (known) l = length of the slide (known) x = distance away from the aircraft (unknown) Pythagorean Theorem: 2 1 2 2 2 2 2 2 2 2 ) ( h l x h l x l h x By fixing f as , can be calculated. The output of the program gives the velocity of an individual and time as a function of position. The arc length is also calculated to check the initial guess of the x component and make sure the arc length obtained corresponds to the length of the slide. 2. Discussion of Results From the equation obtained using Newton’s second law, mass is eliminated as it is on both sides of the equation. Therefore this parameter does not have a direct effect on the results. It is important to note that even if counting for the person size, the mass effect on deflection will not have a big effect and the shape of the slide would not change by much. When mass changes, the weight changes too which has an effect on the coefficient of friction and thus the normal force. The two main parameters that affect the Figure 5: Assuming a right triangle formed when no person slides down x h l

64 results are the coefficient of friction and initial velocity of an individual at the top of an evacuation slide. Figure 6 shows an optimal shape of the A380 upper and lower deck slides as well as of a B747 upper decks slide. The A380 lower deck has a sill height of 5.1 meters and the slide length is 10.2 meters. The A380 upper deck has a sill height of 7.9 meters and the length of the longest slide is 14.7 meters. Similarly, the B747 upper deck has a sill height of about 7.5 meters and slide length of about 13.95 meters. -9 -8 -7 -6 -5 -4 -3 -2 -1 0 0 2 4 6 8 10 12 x (meters) y (m ete rs ) A380 Upper Deck Slide A380 Lower Deck Slide B747 Upper Deck Slide Figure 6: Optimal Shape of Upper and Lower Deck Slides with coefficient of friction of 0.4 and initial velocity of an individual of 6 ft/sec (or 1.83 m/sec) Figure 7 shows the relationship between the velocity of an individual sliding down the A380 upper deck slide and the time. It can be seen that when the coefficient of friction increases, the time it takes for an individual to slide down increases. Also, at higher coefficient of frictions, the maximum velocity and velocity at the bottom of the slide are lower. With an initial velocity of 6 ft/sec (1.83 m/sec), the velocity of an individual at the bottom of the slide is 5.49 m/s for a coefficient of friction of 0.6 whereas it is 8.52 m/s when the coefficient of friction is 0.4. The time required to slide down to the bottom is 1.94 seconds when the coefficient of friction is 0.4 versus 2.17 seconds when the coefficient of friction is 0.6.

65 0 1 2 3 4 5 6 7 8 9 10 11 0 0.5 1 1.5 2 2.5 Time (seconds) Ve lo ci ty (m /se c) µ=0.4 µ=0.5 µ=0.6 Figure 7: Velocity versus Time of an individual sliding on the A380 Upper Deck Evacuation Slide with an initial velocity of 6ft/sec (or 1.83 m/sec) with different coefficient of friction Figure 8 shows the evacuee speed on the slide as the function of time with varying initial velocity. The results show that the effect of initial velocity is minimal.

66 0 1 2 3 4 5 6 7 8 9 10 11 0 0.5 1 1.5 2 2.5 Time (seconds) Ve lo ci ty (m /se c) v0=6 ft/sec v0=7 ft/sec v0=8 ft/sec Figure 8: Velocity versus Time of an individual sliding on the A380 Upper Deck Evacuation Slide with coefficient of friction of 0.4 and different initial velocities Figure 9 shows the comparison in results obtained between the A380 and B747 upper deck slides assuming the same initial velocity of an individual. Regardless of the specific accuracy of the model, the results illustrate that there is a small difference in the maximum velocity and velocity at the bottom of the slide between the upper deck of the A380 and upper deck of the B747. The time it takes to reach down the slide is about the same due to the slight difference in the length of the slides and heights to the top of the slides from the ground. From the results obtained, at an initial velocity of 6 ft/sec and coefficient of friction of 0.4, it takes about 1.94 seconds to slide down from the upper deck of the A380 versus 1.88 seconds to slide down from a B747 upper deck slide.

67 0 1 2 3 4 5 6 7 8 9 10 0 0.5 1 1.5 2 2.5 Time (seconds) Ve lo ci ty (m /se c) A380 Upper Deck Slide (µ=0.4) B747 Upper Deck Slide (µ=0.4) A380 Upper Deck Slide (µ=0.6) B747 Upper Deck Slide (µ=0.6) Figure 9: Velocity versus Time of an individual sliding on the A380 and B747 Upper Deck Evacuation Slide with an initial velocity of 6ft/sec (1.83 m/sec) B747 Emergency Evacuation Events and Airbus A380 Certification 1. B747 Slide Emergency Evacuation Events Major searches from different databases were done as a study for the National Academies of the Transportation Research Board to find slide emergency evacuation events. The events collected included both accidents and incidents over a ten year period from January 1, 1996 to June 30, 1996. The searches done concerned US air transport operations under Part 121, both scheduled and unscheduled. Several databases were used: FAA incident database, Aviation Safety Information Analysis and Sharing (ASIAS) NTSB's accident database CASE Database by Airclaims RGW Cherry & Associates Limited database An additional search was done to capture Boeing 747 Part 129 slide emergency evacuation events. From the 142 slide emergency evacuation events identified for the study for the Transportation Research Board, only 2 of those events involved B747 aircraft.

68 One event occurred on August 19, 2005 in Agana, Guam. A Boeing 747-200 landed with its nose gear retracted and an emergency evacuation was initiated. Two minor injuries occurred during the evacuation. The second event occurred on May 1998 involving a B 747-400 in Tokyo. A very detailed report was found for this event produced by the Ministry of Transport of Japan; “Aircraft Accident Investigation Report” (Aihara, 2000). This report states that of the 385 persons aboard, 365 passengers and 20 crew members, there were 4 serious injuries and 20 minor injuries. The report states that the four serious injuries were females aged between 38 and 73 and consisted of different types of fractures. Minor injuries suffered mostly from bruises, sprains, contusions, exocerations, abrasions, etc. The flight attendant that got injured stated that she picked up an elderly woman who was trembling at the top of the slide and took her down the slide. She got an injury on her right foot but no fracture. One female, aged 65, was seriously injured, from sliding down. She said that passengers were throwing away their belongings while she was on the slide. Her right index finger was fractured from a heavy briefcase that hit her hand. In addition to this, she hit her lower back against the ground at the bottom of the slide as there was no ground assistance. Another female, aged 73, sustained a serious injury at the bottom of the slide. She stated that “Sliding down was so fast that I was worried about being injured by the speed”. She jumped at the bottom of the slide and while she was covering her face and head, she fractured her right arm. A passenger from the upper deck reported that he did not receive any guidance on evacuating. He mentioned that he deplaned via the ramp, connected to the airplane, and did not evacuate using slides. According to the report’s analysis, they estimate that all the injuries occurred sliding down or at the bottom of the slide (Aihara, 2000). Additional search of the data beyond the scope of the TRB study was conducted to identify additional events involving VLTA. Only one event was found on NTSB’s database for Part 129 slide emergency evacuation event involving a Boeing 747 aircraft, which was operated by Iberia Airlines. The accident occurred in Jamaica, New York on August 11, 2002. Two passengers were seriously injured and one flight attendant and 34 passengers sustained minor injuries. Ten passengers were transported to medical facilities for treatment. A female passenger fractured her ankle. It was noted that the slide/rafts doors 4R and 5R did not work properly and all the 369 passengers and 17 crew members evacuated using 1R, 2R and 3R doors (NTSB Aviation Accident Report). In addition to these events, an article was published by the Cabin Crew of Flight Safety Australia in July – August 2005 about emergency evacuations. It describes a B747-438 slide emergency evacuation event that occurred at Sydney airport on July 2, 2003. A very detailed investigation report was found, which was done by the Australian Transport Safety Bureau (ATSB, 2003). Due to fire on the right landing gear, the captain ordered the passengers to evacuate and deployed the aircraft’s slides. There were four serious injuries resulting from the evacuation. The injured included one crew member and three passengers (out of the 350 passengers and 14 cabin crew). Four passengers and one cabin crew member suffered from minor injuries. Figure 10 shows the Sydney incident.

69 Figure 10: Slide emergency evacuation of a Boeing 747-438 (Sydney, Australia, The most serious injury occurred to one woman while she was on an over wing slide at the time it deflated. She got a fractured vertebra that required surgery as she landed heavily on the tarmac. One passenger sustained a fracture to her arm and another to her foot as a result of using the evacuation slides. As far as the upper deck left side, the L2 and R4 escape slides did not deploy. The upper deck right slide was deployed but the crew declared it was blocked by a vehicle. The ground crew freed the slide and turned it to the right position on the ground. Upper deck passengers descended to the main deck and therefore did not use the upper deck slide to evacuate, but the copilot did. He descended on the upper deck right side while he was holding a 3kg fire extinguisher. The copilot stated that he was unable to control his speed and stability. He released the fire extinguisher while sliding down but due to momentum, he landed heavily on his shoulder and fractured his collar bone. Some injuries were cuts, abrasions, sprains and bruises. One female passenger got injured at the bottom of the slide as she fell and cut her right elbow. Her husband evacuated holding his infant on his right hip with his right arm. He stated that he believes he tried to slow down using his left arm. Due to his fast descent, he also fell at the end of the slide, tearing his clothes and cutting his left knee and hand. The cabin crew noted difficulties during the evacuation process. Some flight attendants let people take their belongings with them while others forced people not to take them when evacuating. Thus, some passengers evacuated down the slides with their cabin baggage. Passengers taking luggage or wearing high-heeled shoes risk damage the slide as they slide down. It was also observed that passengers collided with each other at the bottom of the slides as they did not do know what to do next. The ground crew decided to assist the passengers and directing them away from the aircraft (Australian Transport Safety Bureau, 2003). July 2, 2003) (Photo source: Australian Transport Safety Bureau)

70 2. Airbus A380 Certification As mentioned, any new aircraft to enter service must pass the certification test. Certification is needed for all new aircraft models introduced in service. It is to ensure that the aircraft model and crew training provide safety. The main rule is known as the “90 second rule” which concerns the maximum exit time allowed for evacuation. The list of the critical requirements needed to attain FAA certification can be found in Appendix C. Results obtained from the certification test are considered as private, or are considered Airbus proprietary or Goodrich (slide manufacturer) which can not be disclosed to third parties. Many attempts were done to gather any type of information available to public. Data, such as the A380 slides and doors characteristics as well as certification cabin evacuation test results, were obtained from Jean-Michel Govaere, A380 Chief Airworthiness Engineer. For the evacuation test, Airbus recruited volunteers to meet the population requirements. The test was held in March 26, 2006. Figure 11 shows the certification test. The A380 then received joint European Aviation Safety Agency (EASA) and Federal Aviation Administration (FAA) Certification in December 2006. The population of the aircraft was 873 which included 315 passengers on the upper deck, 538 passengers on the main deck, 18 cabin crew members and 2 cockpit crew members. The A380 certification test passed both Part 25 and Part 121 requirements, FAR 25.803 (c) including Appendix J and FAR 121.91: FAR 25.803 sates that “for airplanes having a capacity of more than 44 passengers, it must be shown that maximum seating capacity, including the number of crewmembers required by the operating rules for which certification is requested, can be evacuated from the airplane to the ground under simulated emergency conditions within 90 seconds”. Appendix J to Part 25 lists the certification requirements which can be found in Appendix C. FAR 121.91 states that “this subpart prescribes rules for obtaining approval of routes by certificate holders conducting domestic or flag operations”. From the test results, there were no serious injuries and only very minor injuries. Minor injuries were not more serious than bruises. It was stated that the injuries were significantly less than the "official" 5% acceptable FAA percent injury rate. The evacuation was performed in 78 seconds which meets the 90 second maximum time. As stated from the results obtained, there was no difference found in the behavior of passengers between those of the main deck and those of the upper deck, with the nominal capacity exceeding in most times 110 passengers per Type A door. No hesitation time was noticed from the passengers jumping from the upper deck.

71 Figure 11: Airbus A380 Certification Test (Source: http://www.airporttech.tc.faa.gov/safety/patterson1.asp) Importance, Relevance, and Potential Impact of the Study Safety standards have been maintained throughout the years in order to provide safe and efficient passenger evacuations. This study reviews emergency evacuation challenges of very large transport aircraft. There have been many concerns about emergency evacuations of the future world’s largest transport aircraft, the Airbus A380 due to its massive passenger capacity and aircraft size. This study underlines and analyzes the evacuation “results” from larger transport aircraft. Conclusions and Recommendations This study focused on slide emergency evacuations from upper decks of very large transport aircraft. Several initial parameters were changed to see the effect they had on the velocity of an individual as a function of position on the slide. The graphs show and compare the results between sliding down from the upper deck of the Airbus A380 versus B747. Certification requirements are based from only one single evacuation trial which can be skeptical on the capability of the evacuation. Unlike certification evacuations, passengers may be subject to other type of behavior in real emergency evacuations. There are concerns about this double deck aircraft and how real life emergency situations would differ from the drill conditions. One major point to note is that as the evacuation drill takes places in a dark environment, it is hard to come up with the conclusions Airbus made about the upper deck slides passengers’ behavior. However, as the test was conducted in complete darkness, it is not surprising that passengers did suffer from minor injuries.

72 A number of factors affect the safe evacuation of passengers. As mentioned, passenger’s reactions and decisions will have an effect on the overall process. The uncontrolled manner of passengers in an evacuation can result in injuries. Passengers’ unexpected reactions is hard to predict as they are not always those one would expect. The height of the upper deck slide could disturb passengers, refusing them to jump. This would create more panic for the rest of the passengers. Another major concern is the possible migration of passengers from the upper deck to the main deck using the stairs that connect the two decks. This could lead to a potential problem for the main deck doors due to the extra flow of passengers which would disrupt the evacuation process. It is the role of cabin crew to communicate, coordinate and redirect passengers. The huge crowd in this large aircraft may increase panic in case of an incident. Emergency evacuation models can help to simulate different scenarios. There are, however, countless interactions that could occur during a real emergency evacuation that can not be tested. However, these are recommendations that should be taken into consideration for safer evacuations of large transport aircraft: Increased number of ground assistance and personnel needed. Due to the massive passenger capacity, it is crucial personnel at the bottom of the slides are there to make sure they direct passengers such as getting them out of the way as quickly as possible, calming them down and securing safe paths to protect them. It is also very necessary to have ground operation personnel to hold down the slides and assist them at the bottom due to the higher speed from the upper deck slides. Increased training on communication and coordination between cabin crew. They must be able to manage a safe evacuation of a massive number of passengers. Crowd management training is crucial. Also, new systems may be required to increase effective communication. - Cabin crew is one of the most important aspects against large transport aircraft evacuation problems. In large transport aircraft, the number of passengers is much greater which could cause confusion for the rest of the people. Provide passenger guidance in the aircraft. If the crew does not direct the passengers the right way, the passenger flow rates at different exits could create a major problem. It is their role to direct passengers in an orderly manner and to avoid upper deck passengers to go down to the lower deck. New passenger briefings and new evacuation procedures. It should be made clear to the passengers not to use the stairs during an emergency evacuation. Evacuations of the two cabins should take place in a separate way while at the same time. It is certain that future research will continue on very large transport aircraft and new designs such as blended wing body (BWB) aircraft. A blended wing plane has no tail and has a flat and wide fuselage rather than a circular one. There have been studies that showed performance improvements over conventional transport aircraft such as increased

73 lift and therefore improved fuel economy. Passenger’s flights on blended wing aircraft will be able to carry 800 passengers in a double-deck cabin. Its configuration, involving two decks with multiple aisles per deck, poses emergency evacuation challenges. Concerns on how to handle emergency evacuation of large passenger cabins will be raised such as the location and number of emergency exits that will be sufficient for a safe evacuation, whether the 90 second evacuation requirement will be relevant to this type of aircraft. Bibliography Air Safety Week, “Fire on a Double-Deck Airliner May Affect Evacuation of Upper Cabin”, 25 June 2001, http://findarticles.com/p/articles/mi_m0UBT/is_26_15 /ai_75890806. Airbus A380 vs. Boeing 747, http://larsholst.info/blog/2005/01/20/ Airbus website, “Airbus Approves A380 Successful Evacuation Trial”, 29 March 2006, http://www.airbus.com/en/presscentre/pressreleases/pressreleases _items/06_03_29_a380_evacuation_approve.html Aihara, Yasuhiko (Chairman - Aircraft Accident Investigation Commission), Aircraft Accident Investigation Report, Aircraft Accident Investigation Commission, Ministry of Transport, Japan, December 1, 2000. Asse, Sebastian (Group Manager Cabin Interior – Customers Service Engineering), “Escape Slides and slide rafts A330/A340 Family - Scheduled Maintenance Operational Test” (pp. 2-6), Flight Airworthiness Support Technology, Airbus Technical Digest, December 2003. Australian Transport Safety Bureau – Investigation Report, Boeing 747-438, Sydney Aerodrome, NSW, 2 July 2003, http://www.atsb.gov.au/publications/investigation_reports/2003/AAIR/pdf/aair20030298 0_001.pdf Cabin Safety, January 2007, “The Flight Safety Foundation – AeroSafety World”, http://208.37.5.10/asw/jan07/asw_jan07_p46-49.pdf Classical Mechanics homework – B: Evacuation Slide (p.3-5), www.st-andrews. ac.uk/~ulf/cmhome.pdf. Escoffier, Raphael, “Preliminary Study on Aircraft Evacuation Systems Aging”, Aérazur (Zodiac) Aerosafety Systems Division, 20 December 2001. “Evacuate. Evacuate. Evacuate.” Flight Safety Australia, Cabin Crew. July-August 2005, (pp. 44-47).

74 Eelman, S., Schmitt, D., Becker, A., Granzeier, W., “Future Requirements and Concepts for Cabins of Blended Wing Body Configurations – A scenario approach”. Journal of Air Transportation, Vol. 9, No. 2-2004. FAA Evacuation Drill for Airbus A380, Aviation News, March/April 2005, www.aviationnews.com.au/Past_Issues/Past_Issue_Archives/0503_PDFs/P9.pdf Federal Aviation Regulations (FARS), Part 25: Airworthiness standards: Transport category airplanes and Appendix J to Part 25: Emergency evacuation, http://www.flightsimaviation.com/data/FARS/ Haws, LaDawn and Kiser Terry, “Exploring the Brachistochrone Problem”, The American Mathematical Monthly, Vol.102, No.4 (Apr. 1995), pp. 328-336. Jungermann, H., Fischer K., Beherendt, L. & Gauss, B., “Evacuation from the Upper Deck: Merely an Exit Problem? (if a problem at all)”, Atlantic City, October 22-25, 2001. Jungermann, H., “A psychological model of emergency evacuation from double-deck aircraft”, Australia, November 20-24, 2000. Jungermann, H., Gohlert C. , “Emergency evacuation from double-deck aircraft”. In M.P. Cottam, D. W Harvey, R. P. Pape & J. Tait (eds), Edinburgh, 15-17 May 2000. Vol 2.Rotterdam: A. A. Balkema. pp. 989 - 992. Phillips, Thomas J. (Captain) Air Line Pilots Association, International, “Airbus 380 Meeting the Challenge in 2006 - International Forum on Airport Emergency and Management”, Singapore Aviation Academy (SAA), January 10-12, 2005. Rosenkrans, Wayne, “How Airbus emptied a packed A380 12 seconds faster than necessary”, Flight Safety Foundation, Aerosafety World, Cabin Safety, January 2007. “Specialists Study Evacuation Challenges of Very Large Transport Aircraft”, Vol.39 No. 4, Flight Safety Foundation, Cabin Crew Safety, July-August 2004 Technical Standard Order, Subject: TSO-C69c, Emergency Evacuation Slides, Ramps, Ramp/Slides and Slides/Rafts, Department of Transportation, Federal Aviation Administration, Aircraft Certification Service, Wa shington, D.C. Verres, “Very Large Transport Aircraft (VTLA) -Emergency Requirements Research Evacuation Study – A project summary” JAA Paper 2003 Wallace, James, “Aerospace Notebook: Critical Evacuation Test Looms for A380”, 22 March 2006, http://seattlepi.nwsource.com/business/263847_air22.htm l

75 Wallace, James, “Aerospace Notebook: This is only a test with 850 passengers”, 2 February 2005, http://seattlepi.nwsource.com/business/210321_air02.html Appendix A- Airbus A380 Slides Lengths and Angles Source: A380 Cabin Evacuation System (Jean-Michel GOVAERE, A380 Chief Airworthiness Engineer, AIRBUS SAS) Appendix B - Matlab Code % Maryline Rassi, 07/31/2007 clear all; close all; clc; % 1. INPUT x = 10.9109; %[m] x distance to the bottom of the slide h = 7.9; %[m] height v_0 = 6*12*0.0254; %[m/s] Conversion: 1 ft/s = 12 in/s = 12*0.0254 m/s mu = 0.42; % Friction coefficient g = 9.81; %[m/s^2] n = 1000; % Counter M Door Slide Length 10.3 m (406.0") – Normal 13.7 m (540.7") - Extended 11.2 m (439.0") 5.7 m (225.0") – Ramp 7.2 m (283.5") - Slide 10.2 m (400.0") 10.2 m (400.0") Slide Angles Normal Sill Maximum Sill Minimum Sill M2 M3 M M5 U1 U2 U3 14.7 m (580.7") 13.9 m (546.7") 13.9 m (546.7") 30° 30° N/A 33.5° 33.5° 35° 38° 38° 47.5° 47° N/A 39° 43.8° 43° 40° 44° 12° 16° N/A 12.3° 5.8° 25.6° 25.7° 19.4°

76 % 2. PROCESSING % 2.1. Calculate the parameters of the curves for j = 1:n t(j) = (j-1)/(n-1) * 2* pi; result(j) = (1-cos(t(j)) + mu * (t(j) + sin(t(j)))) / (t(j) - sin(t(j)) + mu * (1-cos(t(j)))) - h/x; end theta_f = pi rho_x = x / (theta_f - sin(theta_f) + mu * (1 - cos(theta_f)) ); rho_y = h / (1 - cos(theta_f) + mu * (theta_f + sin(theta_f)) ); % 2.2. Calculation of x and y for j = 1:n theta(j) = (j-1)/(n-1) * theta_f; x(j) = rho_x * (theta(j) - sin(theta(j))) + mu * rho_x * (1 - cos(theta(j))); y(j) = rho_y * (1 - cos(theta(j))) + mu * rho_y * (theta(j) + sin(theta(j))); % 2.3. Velocity v(j) = sqrt(2*g*(y(j) - mu*x(j)) + v_0^2); end % 2.4. Time time(1) = 0; % Time initialization s = 0; for j = 2:n dx(j) = x(j) - x(j-1); dy(j) = y(j) - y(j-1); ds(j) = sqrt(dx(j)^2 + dy(j)^2); dt(j) = ds(j) / v(j); s = s + ds(j); time(j) = time(j-1) + dt(j); end % 3. OUTPUT s time(n) figure; plot(x,-y) xlabel('x [m]'); ylabel('y [m]'); axis equal figure; plot(time,v) xlabel('Time [s]'); ylabel('Velocity [m/s]'); figure;

77 plot(y,v) xlabel('y [m]'); ylabel('Velocity [m/s]'); Appendix C – Critical Requirements to attain FAA Certification Evacuation must take place either during the dark of the night or during daylight with the dark of the night simulated, so the plane’s emergency lighting system provides the only illumination in the cabin. Passenger load (in normal health) must be representative with at least 40 percent female, at least 35 percent over 50 years of age, and at least 15 percent must be female and over 50 years of age. No practice runs are allowed before the drill. Passengers can not know the location of the emergency exits to be used. Crew members must be seated in their normally assigned seats. No passengers may be assigned specific seats. Before the start of the demonstration, about one-half of the total average amount carry-on baggage, blankets, pillows and other similar articles must be distributed at several locations in aisles and emergency exit access ways to create minor obstructions. Only half the emergency slides and doors can be used. Evacuation test is over when the last person on the plane (including crew members) is on the ground.