Hi, my name is Kimberly Everett, and I will be giving this year's board review talk on aerospace medicine, management administration, and aerospace operations. This is my first year giving this talk, and I would like to thank Dr. Almond, who gave this presentation for the few years prior to me, and Dr. Davenport, who gave this talk for the 15 years before him. I've made some updates and tweaks, but the content really hasn't changed much, so much of this content and slides are originally by Dr. Davenport. I have nothing to disclose. I am in the Navy, but I am not representing the Navy today. So first, just a couple of general comments about the aerospace examination from a prior chair. The questions are hard. It is normal to walk out of the exam feeling like there are a substantial number that you did not know or maybe did not get correct. This is graded on a bell-shaped curve, really around the middle. For those of us in the military, we're used to thinking about service-specific guidelines, but there are very few service-specific questions on this exam. The questions really have the underlying pathophysiologic principles at heart, and FAA is the common denominator for all of us, so that's really the focus on the exam. You'll do best if you stick with the reference materials and really look for that testable content, meaning things like exceptions, and really the vast, vast majority of the questions are taken directly from the reference materials. It should make everyone pretty happy that if you do put in the effort, the board exam pass rates are very high for aerospace, so from 2017 through 2022, the pass rate was between 85 to 93% for all of those years, and as my former program director, Dr. Allman used to say, know what the herd knows, meaning you have to put in the time and effort, but if you do that, you'll be fine. All right, so today, we're going to talk about management administration, which accounts for 10% of the board exam, which goes over those organizations listed here and the regulations, mainly the Code of Federal Regulations, and then we'll also be discussing operational aerospace medicine, and this accounts for 20% of the board exam. This is an assortment of topics dealing with the actual practice of aerospace medicine, and as you can see, there's a little bit of a potpourri of material here, so we will bounce around a little bit to cover all of this. I'll do my best to weave together themes and storylines to help us remember, but if it seems like I'm bouncing around a little bit, that's because that is what our job is today. All right, and as far as our reference materials, so these actually used to be published by the ABPM, along with the content guide for the exam. They stopped being included in 2018, but the references really haven't changed, so these are still the biggest primary references that you should be using, and although the board exam, such as the board review materials, such as this, are very important, it can be really helpful to go back to those textbooks and the other guidelines, especially for material that you feel like maybe the residency didn't cover quite as well for you, or that you had trouble with during residency. All right, so diving in with organizations. The first organization that we'll be talking about is the United Nations, so the United Nations has 193 member states, and really is important to us because it contains the Economic and Social Council, which in turn creates, which in turn encompasses ICAO and WHO. So the World Health Organization was established in 1948 as a specialized agency within the United Nations, and has 194 member states and several associate member states, which are territories or groups of territories, which are not responsible for the contact of their international relations. It also has several observers, and the goal of the United Nations is attainment by all peoples of the highest possible level of health. The WHO has international health regulations, which are legally binding framework of rights and responsibilities for public health events, and the goal of the IHRs is to prevent, protect against, control, and provide public health response to the international spread of disease. The international health regulations were originally designed to control the spread of very specific infectious diseases, such as cholera, plague, and yellow fever, but after the major revision of the IHRs in 2005, they focused much more on generic public health risks and bioterrorism, as well as adaptive responses instead of very prescriptive responses as they were previously. So the IHRs have minimum requirements for surveillance and response due to the recognition that with the very interconnected world that we have today, that our best chance of really stopping the spread of infectious disease, it's through containment at the source. So IHRs have requirements for reporting of cases, as well as international travel guidelines. They set the criteria for public health emergencies of international concern, such as swine flu, polio, Ebola, Zika, COVID, and monkeypox. And once a public health emergency of international concern is declared, the WHO develops and recommends critical health measures for implementation of those member states. So we've all recognized this. This is our international certificate of vaccination or prophylaxis. So this is the yellow cards that are made by the WHO under one of the international health regulations, and these have our routine vaccinations, our selective use for travelers based on risk factors of the country that's being visited, as well as mandatory vaccinations. So the mandatory vaccinations that exist today include yellow fever for certain countries for the protection of those vulnerable countries, as well as requirements for the Hajj. So meningococcal vaccine is required by Saudi Arabia for all pilgrims, and they do require polio and yellow fever for travelers from certain countries. The international health regulations also contain requirements for airports, ports, and borders to prevent the spread of infectious disease. These were historically called sanitary airports. These requirements detail that all of these airports, ports, and borders must have access to medical services, be able to transport ill travelers, be able to inspect conveyances, have safe facilities, and be able to control vectors and reservoirs of disease. They also need to be able to respond to events. An important part of preventing the spread of infectious disease is aircraft disinfection, which is also documented and described in the IHRs. So this involves the treatment of the interior of aircraft by the application of insecticides to avoid spreading vectors like mosquitoes and the disease they transmit. There's a couple different types of aircraft disinsection. One is called residual disinsection or pre-embarkation disinsection, which is the application of a residual insecticide to all internal surfaces of the aircraft. There's another called blocks or chocks away disinsection, also pre-departure, where the cabin is actually treated with a quick acting insecticide spray while the passengers are on board immediately before takeoff. And there's also a combination of both of these called pre-flight and top of descent disinsection, where both a residual and a pre-departure type insecticide spray are used. So the insecticides used, the original pyrethrin, which is the natural substance derived from chrysanthemum plant seed pods, this has been really replaced by the pyrethroids, which are synthetic analogs to pyrethrins. So we have two types, the permethrins and diphenothrin. The permethrins are used for residual disinfection, they leave a fine residual coating on all of the surfaces within the aircraft and do have low mammalian toxicity and is very poorly absorbed through the skin. Diphenothrin is an aerosol that quickly kills small flying insects, which is used for that knockdown disinsection aboard the aircraft while the passengers are all there. So individual countries will have their own disinsection requirements. And they will specify whether they're the blocks away or the residual disinsection, and then whether they're selected, so meaning depending on where the inbound flight is from, that will make sure that they have the appropriate disinsection being performed. And passengers should be notified of these disinsection requirements at the time of booking. Airport malaria is another interesting case of transmitting infectious disease across countries. So these are cases where mosquitoes are transported via the aircraft from malaria-endemic areas to malaria-free areas, and then bitten and infected individuals near the airport. These have been documented in numerous countries. Baggage malaria is very similar, but is caused by the baggage that actually harbors the malarial mosquitoes. Fly malaria is an even more specialized type of malaria transmission where passengers on an aircraft become infected on an intermediate stop. So for example, traveling from D.C. to England via Honduras, in that case, the passenger stays on board the aircraft in Honduras, mosquitoes fly on, infect the passenger, and the passenger continues on. The WHO also publishes International Travel and Health Guidelines. The major revision was last in 2012, but it was updated, a couple chapters were updated in 2019. And you can see here, these are the table of contents, which includes a variety of topics for preventing illness in the traveler. As far as health within the United States government, this is primarily taken care of within the Department of Health and Human Services, which contains the CDC. So similar to the WHO, the CDC puts out guidelines for travelers called the Yellow Book. The 2024 contents are listed here. There's been a little bit of reorganization, but really the content is here for the practitioner to help prevent infectious disease spread among the traveler. So switching gears just a little bit, we'll talk about ICAO next, the International Civil Aviation Organization. So this really got its start in 1919, post-World War I, with the Paris Peace Conference. In 1922, within the League of Nations, the International Commission for Air Navigation was established. And then in 1944, this is really what started ICAO, the U.S. organized the Convention on International Civil Aviation, called the Chicago Convention, which did establish ICAO in 1947. So the objective of ICAO is the safe and orderly growth of international civil aviation. There's 193 contracting states, and these states maintain sovereignty over their own airspace, but they do abide by the regulations set forth by ICAO in regards to air travel. There are 19 annexes within the Convention on International Civil Aviation, which encompass SARPS standards and recommended practices, which are the most common type of guidelines, and then procedures for air navigation services, which are slightly more regional, and regional supplementary procedures called SUPS. SARPS are considered binding, however, if a contracting state finds it impossible to comply, then the state can inform ICAO of any differences that exist, and that will be published. So an example of a SARP in 2005, there was a SARP that reduced their vertical separation mins from 2,000 to 1,000 feet over the Americas and several other countries. So here are all the annexes of ICAO. You can really see that it encompasses the breadth of conducting aviation business. Here's another example of a SARP, which has universal SAR signal codes that are used across countries. There's an aviation medicine section of ICAO, which monitors developments in aviation medicine worldwide and helps keep Annex 1, our personal licensing section, up to date. These medical SARPS have minimum requirements for contracting states regarding medical licensing of aircrew. They do allow some degree of flexibility within the members, and they work closely with the WHO, ASMA, and other organizations. There are several other organizations that are of interest to us also, the International Air Transport Association, the International Federation of Airline Pilots Association, and the Airports Council International, to name a few. There's also the International Academy of Aviation and Space Medicine, which has a membership made of people that have made outstanding contribution to aerospace medicine, and it exists to promote and search for new knowledge in aerospace medicine. None of these organizations exist in a vacuum, and they all really work together. A great example of this is the SARS outbreak that occurred in 2003. There's this novel type of pneumonia that started in China, and travelers went to Hong Kong, and from there, got on airplanes to many other countries, including the US. There were public health organizations within the United States that noticed these types of pneumonia, and information was gathered up by the CDC and by the other public health agencies by all of these other countries, and that was funneled to the World Health Organization. The World Health Organization then informed the ICAO of what was going on, which in turn set protective measures and recommendations to help prevent the spread of SARS through air travel. There's some other examples of how these organizations work together. So these are CDC guidelines. Here we can see these are Ebola guidelines for airlines, and then infection control guidelines for cabin crew members on commercial aircraft, and then these will go to inform asthma recommendations. As we can see here, this press release from asthma directly quotes the CDC guidelines. This is just a quick cartoon showing how you can get more room on an airplane this was pre-COVID, but certainly rings even more true today. This is a quick aside about another organization, NIOSH, that certifies particulate respirators and how they are described. So it is important that you understand the abbreviations here. So N95, that we're most familiar with, N being not resistant to oil, 95 meaning the mass filter 95% of particles greater than 3.3 microns that attempt to flow through the mask. And then we see that our HIPAA filters are at least 99.97% efficient in removing those particles that are 0.3 micrometers in diameter. For medical use, the masks will be NIOSH and FDA certified, but there are non-medical N95 masks that may be certified only by NIOSH. All right. So our first question, the international certificate of vaccination must conform to the requirements of annex six of the international health regulations. Which of the following methods for completion would not provide an acceptable certificate? A, a certificate signed and stamped by the medical practitioner or other person. B, a certificate issued collectively for a mother and her infant. C, a letter from a vaccinator stating the rationale for his medical opinion that a specific vaccination is common. Or D, for a military member, a vaccination document, which contains the same information in lieu of the international certificate. So our answer here is B. The IHR states that the international certificates are individual certificates and shall in no circumstances be used collectively with separate certificates being issued for children. All right. Switching gears to the Department of Transportation. All right. Switching gears to the Department of Transportation. So the DOT was established in 1967, incorporated multiple government agencies, including the FAA, the U.S. Coast Guard at the time, and the NTSB. Currently, the DOT has several organizations of interest to us today, primarily the FAA, but also the Research and Innovative Technology Administration, or RITA, which contains the Bureau of Transportation Statistics. And this organization produces a lot of the accident statistics that we'll review later. All right. So the FAA really got its roots in 1926 with the Air Commerce Act, which was the first real attempt in the U.S. to improve air safety standards and standardize the industry. In 1934, it was renamed the Bureau of Air Commerce. And then in 1938, it was called the Civil Aeronautics Act was released, which created the Civil Aeronautics Authority. And then in 1958, after a series of high-profile aviation mishaps, the Federal Aviation Act was passed, which created the Federal Aviation Agency. And in 1967, this finally became the Federal Aviation Administration, a part of the DOT that we know today. So this was the one of the big high-profile mishaps that led to the creation of the FAA. So there were two aircraft that crashed in the Grand Canyon in 1956. And you can still visit that site today. And these two commercial aircraft, there were clouds that came over the Grand Canyon, and there was no real standardized way for them to communicate with each other. So this was a completely preventable midair that really was the result of not having standardized air traffic control and communication procedures. So the functions of the FAA. So it regulates civil aviation for safety and national defense, encourages new civil aviation technology, operates a common system of air traffic control, has research and development in national airspace systems, develops noise and environmental protection effects, and regulates the U.S. commercial space transportation industry. So that's of importance because a lot of people might think that would be NASA, but really, remember, that's the FAA. And the FAA does have enforcement authority, which is also important to remember. So here's the structure within the FAA. So within aviation safety, we see that there is an accident investigation section, as well as our aerospace medicine section with our federal air surgeon, our regional medical divisions, and CAMI. The National Transportation Safety Board was established in 1967, first under the DOT, and then became independent by 1975. The NTSB investigates all civil aviation accidents, as well as several other types of transportation accidents. It determines causal factors and may make safety recommendations, but does not have any regulatory or enforcement powers. The material that it gathers is of a safety nature and is not evidentiary in a court of law. As an additional function, it's important to remember for our purposes that the NTSB also serves as the court of appeals for aviators who are denied medical certification by the FAA. The NTSB investigates about 1,800 aviation accidents per year, as well as around seven major overseas investigations. The NTSB is the lead agent, except in criminal cases, when that becomes the FBI. In accidents that occur on foreign soil, the host government has jurisdiction, but the NTSB may send representatives. And the NTSB does have a significant number of aerospace medicine and survival specialists. The NTSB has GO teams that are dispatched for very high visibility mishaps, which might happen around five to 10 times a year, where they have an investigator in charge and numerous specialists. These GO teams can be deployed to the U.S. and international waters. For all aircraft investigations, the FAA does participate. The NTSB can defer to the FAA for onsite air accident investigation and routine general aviation accidents, which occurs about 80% of the time. And the rest of the accidents are investigated by one of the NTSB regional investigators. But remember, the NTSB are the ones who make the final determination on all mishap causal factors. The NTSB also puts out a most wanted list of factors or things to work on regarding transportation safety. So we can see for this current most wanted list, for aviation, the goals are to require and verify effectiveness of safety management systems and to install crash-resistant recorders and establish flight data monitoring programs. This is for 2019 through 2020. We can see the most wanted list includes ending alcohol and other drug impairments, improving the safety of part 135 aircraft flight operations, reducing fatigue-related accidents. Our second question, what specific organization or group is held responsible by federal law for determining the cause of all U.S. civil aircraft accidents? So we just went over this. Can read the options here. And the correct one, of course, is C, the NTSB. So this is an example of an interesting crash that really demonstrated all of the different types of authority that can exist when investigating aircraft. So this was a crash that occurred in 2012 between one airplane that was owned and being piloted by an employee of the NTSB and another aircraft that was owned and being piloted by an employee of the FAA. And there was a midair collision between these two aircraft. However, under Annex 13 of the ICAO Convention, it is possible that the U.S., if it has reason to and under mutual agreement, can ask another country to investigate accidents. So in this case, based on the conflict of interest, this investigation was actually delegated to the Transportation Safety Board of Canada. The NTSB designated a representative to help the Canadians and then the FAA designated an advisor to that NTSB representative. So we can see here, this is that ICAO Chicago Invention that we've mentioned before with the SARP that is the Aircraft Accident and Incident Investigation. So this is the document that does specify the responsibility for conducting aircraft investigations. All right, so the origins of NASA. So in 1915, the National Advisory Committee for Aeronautics was added to a Naval Appropriations Bill chartered to direct and conduct research and experimentation in aeronautics. And aeronautics research at the time was conducted in a variety of locations. In 1958, the National Aeronautics and Space Act created NASA, which incorporated NACA and those related centers, as well as added several research laboratories. Here we can see some of the most prominent missions that NASA has worked on in its history that you can review. So today, NASA is very focused on the Orion spacecraft which is the human exploration vehicle for deep space missions. So Artemis I was a mission conducted in November 22 of an unmanned lunar flyby. And then Artemis II is kind of a similar mission except manned, which will occur in 2024. These are really graduated missions that will be setting the stage for a lunar landing with the goal of eventual manned Mars exploration. And other focuses of NASA are continuing the International Space Station and commercial space operations support. All right, so now we're going to switch gears and talk about regulations. So the Code of Federal Regulations, CFR, Title 14 is the aeronautics and space, so the federal air regulations. So we'll be talking about part 61, 67, 91, part 121 and part 135 today. So part 61 is our certification process, part 67 are medical standards, part 91 is our general aviation, part 121 are regional major airlines. These are scheduled commercial air travel. And then part 135 is commercial, but commuter air taxi. So it's on demand or unscheduled air operations. And you can see all of the Title 14 in the CFR online, it's actually pretty easy to search. All right, so again, we're focusing on part 61 here. We can see that just as an example, something that might be in part 61 about the certification of pilots are offenses involving alcohol and drugs. So part 61 requires that a DUI conviction requires that a certificate be denied and that a pilot be reported to the FAA. And then part 91, general operating and flight rules, we also has alcohol and drugs. So we can see that these regulations state that you cannot crew an aircraft if you're within eight hours of alcohol consumption, if you are under the influence of alcohol with a BAC more than 0.04, have any other drugs on board compromising your safety, and you cannot have any inebriated or impaired passengers. All right, so then in parts 121 and 135, these are again our airline and then our on-demand operations. So in general, part 121 operations are stricter because those are the ones that are, what we traditionally think of as our major airlines and our regionals that have a significant passenger population on board. So for example, as far as our flight time limitations, they're stricter in part 121 than part 135. So we can see that the pilots in part 121 are limited to a thousand hours a year, 30 hours in any week with eight hours between rest periods, where for example, our part 135 pilots are limited to 1,200 hours a year with 34 hours in any seven consecutive days and eight hours of rest in any 24 hours. So switching gears to talk about fatigue. So fatigue as an issue within aviation has really existed as long as aviation has been around. So there's a quote from Charles Lindbergh, I've got to find some way to keep alert, there's no alternative but death and failure. And the NTSB has constantly had fatigue as one of the most important issues to be addressed and is very frequently on the most wanted list. Fatigue was implicated in a famous crash with Colgan Air and that occurred in 2009, that killed 50. So on the 12th of February in 2009, the Colgan pilots, these are as a regional airline, entered a stall and the plane crashed into a house killing all 49 on board and one person on the ground. The pilots failed to recognize the impending stall and did not respond appropriately to staff's warning. This accident really called into question regional airline training practices and fatigue policies. The captain on the aircraft had flown to Newark the day before and had slept in the airline's crew room where the first officer had commuted overnight and had slept in a crew lounge before the flight. Investigators found no evidence that either pilot had stayed in a hotel or other lodging to get a good night's sleep in Newark before taking off. And this accident really helped inform some new fatigue rules that finally went into place in 2014. So there were increased scrutiny again on the flight and duty hours, so these were made stricter and these are changed to have the max flight and duty hours based on the time of start of the flight duty period to try to account for circadian effects and the night trough between 02 and 06. The flight duty period is nine to 14 hours which begins with reporting for duty and includes time before or after flights, sims, deadheads within duty periods and planning. Flight time is limited from eight to nine hours in unaugmented operations and this is while the aircraft is moving under its own power. The rest periods were increased to 10 hours from a prior eight hours which mandates eight hours for uninterrupted sleep and it became the airline and the pilot joint responsibility to ensure the fitness for duty before each flight. The off-duty time each seven days was increased to 30 hours and this law revised cumulative weekly and monthly maximum flight times and duty times. Some critiques of this law, it didn't include cargo flight crews, did not include part 135 or flight attendants and it doesn't address the deadheading or pilot commuting or crew lounge utilization that occurs before the flight duty periods begin. We can see here this is from the CFR and this has the maximum flight duty periods for lineholders based on the number of flight segments based on the scheduled time of start. So a rather complicated way that we can see of figuring out the maximum flight duty period but again to account for the circadian rhythm and the kind of workload with the number of flight segments. Fatigue risk management systems are required by part 121. So ICAO defines a fatigue risk management system as a data-driven means of continuously monitoring and managing fatigue related safety risks. These are more comprehensive than very prescriptive flight duty rules and each domestic airline has to have a fatigue risk management system approved by the FDA, approved by the FAA, excuse me and these fatigue risk management systems must include a fatigue risk management policy, education awareness training program, a fatigue reporting system, system for monitoring crew fatigue and incident reporting process as well as performance evaluation. Okay, so that brings us to our next question. When operating an unpressurized aircraft supplemental oxygen by mask may be necessary to prevent hypoxia in flight crew and passengers. According to the federal aviation regulations above what altitude is supplemental oxygen required to be provided for each occupant of the aircraft? So our answer is D, above 15,000 feet, oxygen is required for all occupants of the aircraft. All right, so we'll switch gears a little bit to civilian air travel. So first a few words about cabin air pressurization. So most planes use engine bleed air to pressurize the cabin. So typically this means that the pressure is really created by limiting the outflow. However, there are a few aircraft including the Boeing 787 that use a separate electric air compressor to pressurize instead of the engine bleed air. So this has the potential improvement of having better air quality because the air is not coming through the engines first before it is being pressurized. So you may have reduced volatile organics. Cabin altitude on our commercial aircraft is kept between 5,000 to 8,000 feet. So it was designed to keep the oxygen saturation above 90% in our healthy travelers. However, there have been some concerns that even a cabin altitude up to 8,000 feet could pose a risk to some travelers especially those who are older. This study shows the percentage of individuals with a arterial oxygen level less than 50 by age in accordance with the cabin altitudes. So you can see here, let me get my laser here. So you can see that, let's see for a 65 year old at 8,000 feet, there's actually a pretty decent percentage that might be expected to have a fairly low arterial oxygen level. So many airlines now voluntarily fly with slightly lower cabin altitudes partially for this reason. As we discussed with our former practice question, so the FAA has oxygen requirements in an unpressurized cabin, oxygen is required for crew for any flight more than 30 minutes in altitudes above 12,500 feet and at any time above 14,000 feet. And as we saw in our question, above 15,000 feet oxygen must be provided for all occupants, not just the crew. Okay, so for cabin ventilation, so as we go up in altitude, we have increasing levels of ozone and at the altitudes where airplanes fly, our ozone could be up to one part per million which needs to be reduced for our passenger population. So ozone in the cabin air is reduced by catalytic converters with an ozone limit of 0.1 per per million continuous and 0.25 per per million peak per the FAA. Carbon dioxide levels also exist at a higher level than will be desired in the aircraft if not for all of the ventilation that takes place. So the FAA sets regulations that carbon dioxide may not exceed 0.5% or 5,000 per per million. However, as we'll see in our next slide, typically our cabin carbon dioxide levels are kept to about 1,500 parts per million and this is really a measure of overall ventilation effectiveness. Typically the commercial aircraft have 50-50 recirculated and fresh air, so about 20 to 30 exchanges per hour. So here we can see at my pointer again that here's our typical cabin carbon dioxide level at cruise and then we can see that at 2,000 parts per million up here, 2,000 part per million, this is when actually a lot of occupants will start to feel some degree of discomfort but then our regulation limit is not up until 5,000 parts per million. So pretty interesting and then our toxicity level is a little bit higher than that. So some other notable features of our aircraft cabin environment. So as we all know, there's a pressure deficit and due to Boyle's law, we will see expansion and there's dry air. So the dry air, about 10 to 20% humidity can affect respiratory passages, the skin and cornea. Also, as we know, airplanes have cramped space so this could exacerbate peripheral edema, circulatory problems and could increase the risk for DVTs. There's also vibration and turbulence which could impact passengers who have medical conditions or recent medical procedures and cause pain. Okay, moving on to talk about filtration and airflow in the cabin environment. So in our commercial aircraft, HEPA filters do remove the vast majority of viruses and bacteria. The airflow in the cabin is lateral, meaning that the air comes down from the center, out to the side and then around back up. So disease transmission is really highest in that same row and then plus or minus two rows. Inflake disease transmission has been demonstrated for multiple illnesses, including tuberculosis, flu, measles, meningococcal disease, SARS and COVID. Transmission depends on proximity to the source, duration, the ventilation and the source strength. This can vary pretty dramatically. There was a really interesting example in 1979 where an airliner was delayed for three hours on the ground so its cabin ventilation system was not working and at the end of the flight, 72% of the passengers had developed the flu due to the significant exposure and lack of ventilation to that source. So another interesting case of in-flight or the potential for in-flight disease transmission. So in 2007, there was an American who was infected with extremely drug-resistant tuberculosis that traveled on multiple flights to Europe, around Europe and then back. And then the CDC actually had to work with the WHO and identify all close contacts on the flights. He had been on multiple flights, so they decided that the higher risk flights were those more than eight hours in duration for the transmission of tuberculosis. They contacted all 292 US passengers, identified 26 high-risk passengers, so who were in the same row or plus or minus two rows in the cabin. And all of those people had to get TB testing immediately and in eight to 10 weeks per the WHO guidelines. This is an example of the WHO passenger locator card. So this is used when public health authorities suspect that there's the potential for disease transmission on board and that there might be a need for contact tracing. These were used in COVID, especially it's our most recent example. So typically it is fairly difficult to deny the ability to travel by air from commercial airliners. So this regulation states that passengers may only be excluded if a passenger's disease presents a direct threat, meaning it's readily transmitted during the course of flight and has severe health consequences. So something like a cold that might be easily transmitted, but doesn't have severe health consequences, you couldn't restrict flight. Something like HIV that is not readily transmitted, but is severe also couldn't restrict flight. So we're limited to those examples where both of these conditions are met. So now we're going to be talking about some of the recommendations from the medical considerations for airline travel. This is on the asthma website. Highly recommend that you at least open up and kind of peruse some of these documents. It's pretty helpful source information. So pre-flight medical clearances are done when a passenger needs a fitness to fly advice for specific medical concerns. It really does depend on some of the factors that are related to medical concerns. It really does depend on self-declaration by the passenger. It's required when there's a doubt of fitness to travel, did a recent hospitalization, illness, injury, or surgery, or a concern for communicable diseases or other hazards. Also performed to that passenger may require special assistance or require special services. The passenger's personal physician typically provides a note, but they likely don't know the aviation aspect. So most airlines will then run the cases with their advisors who will use policies based on asthma or AIDA. There's a couple of different forms that are used. So one is the medical information form, which is kind of the equivalent of the doctor's note, and then also a frequent traveler's medical clearance, which are for stable medical conditions and a longer lasting evaluation that's done by the the traveler's personal physician. So in this process, a traveler would call the booking agent, inform of a medical problem, get transferred to a medical desk, and the airline would send the forms to the treating physician, it's in the back to the airline, and the airline either approves it or sends it to their own medical advisor, and then the traveler's notified and a note is put in their file. So the regulations do state that oxygen is can be used by passengers, but it does, so it allows the airline provision of oxygen. It requires physicians to state the need, the flow rate, and the quantity that a traveler may require. Does not allow for personal bottled or liquid oxygen equipment, but it does permit oxygen concentrators. However, airline policies and costs related to this are extremely variable, and they may or may not allow personal oxygen concentrators on board. Even if the oxygen concentrators are provided or allowed on board, there still can be a fair amount of difficulties for passengers, including the cost, dealing with layovers, or transfers between airlines. All right, so now I'll go through a few of our assessment considerations for a physician evaluating whether or not a traveler is safe for commercial air travel. So we'll be thinking about relative hypoxia, which is important when we think about cardiovascular, pulmonary, or anemic disease. The expansion of trapped gas, particularly important after surgery, and then our risks of DBT, also important after recent major surgery. These are guidelines that I've taken from the ASAM's guidelines online, which are a number of different source papers and documents. Highly encourage you to read them. So these guidelines state that we shouldn't accept a heart attack within seven days of travel, uncontrolled heart failure, open heart surgery within 10 days, or anemia less than seven and a half milligrams. And these require that doctors note that MEDEF for AMI or heart surgery within 21 days. Respiratory disorders, I recommend not accepting pneumothoraces within 14 days, chest surgery within 10 days, or dyspnea after 50 meters of ambulating, and then requiring that note again for surgery within 21 days. For fractures, recommend not accepting fractures in plaster within 48 hours unless the splint is bivalved. For surgery, recommend not accepting open surgery within 10 days. However, laparoscopic surgery would be okay after 24 hours if all the gas is absorbed, but would require that physician note. For pregnancy, typically uncomplicated pregnancies are well tolerated at flight environments. The mother has several ways of compensating with hyperventilation, tachycardia, and then of course, fetal hemoglobin that preferentially steals oxygen from mom, which can compensate for reduced arterial pressure. In first trimester though, if there's any complications such as bleeding or pain, the recommendation would be to not fly. Later in pregnancy, most airlines do allow travel up to 36 weeks for singleton pregnancies. There's not really an increased risk of radiation for occasional travel, but there potentially is for air crew. Their usual recommended limit is about one millisieverts, which we could exceed that recommendation after 10 flights from Toronto to Frankfurt. So you could see how a flight attendant, for example, going on a lot of international flights, would be able to fly with long legs, might go over that limit. Also, even for single trips during solar flares, could get pretty high radiation, and then trips near poles or long flights will also increase the dose of radiation for the pregnant traveler. However, airport scanners are of no increased risk. So the radiation from an airport scanner is equivalent to two minutes of air travel. Passengers with disabilities are protected by the Air Carrier Access Act, so the airlines may not refuse to fly anyone with a disability unless it would jeopardize the safety of flight, and they must provide written justification. They also can't limit the number of disabled people on flights, assign specific seats, or require advanced notice except for safety concerns. The airlines have to assist with boarding and connections, and again, they must allow personal oxygen concentrators if they're FAA approved. They also must allow travel with a service animal. Now switching gears to talk about medical emergencies or events in flight. So about 24 to 130 per million passengers have medical incidents. This is about one in 600 flights. And then for in-flight deaths, that's about 0.3 to 0.7 percent of incidents, so 0.1 death per million passengers. One half to one third to two thirds of deaths are cardiac related. There have been several studies about medical emergencies. This one's a little bit old, but it's actually still one of the most cited due to the excellent data. This study looked at five commercial airlines from January of 2008 to October of 2010 and had almost 12,000 incidents, which again is we get that one per 600 flights. They noted that the top five reasons for having that medical emergency were syncope, respiratory symptoms, GI symptoms, cardiac symptoms, and neurologic symptoms. When the airlines asked for volunteers, almost half had physicians, 20 had nurses, 20% had nurses, and another 8% had EMS and others. And these medical emergencies resulted in seven percent, seven percent of those resulted in diversions. Deaths in flight, very rare, however we can see the most common cause is cardiac arrest. So in a study looking at in-flight cardiac arrests, which are again 0.3 percent of the in-flight medical emergencies, can see that about a quarter had shockable rhythms, and out of those, 11 out of 97 survived a discharge. However, our 75% with non-shockable rhythms, only two of those survived a hospital discharge. And in the case of diversions, so this is estimated to be about four to seven percent of in-flight medical events, the most common causes are cardiac arrest, cardiac symptoms, obstetric emergencies, and stroke symptoms. It's important to remember that the final decision to divert is up to the pilot, and usually that will be made in discussion with both the on-board medical volunteers and crew, as well as on-the-ground medical consultants. Emergency care on board. So flight attendants are trained in CPR, AEDs, and first aid, and that's by regulation. There are AEDs, advanced medical kits, and oxygen bottles on all U.S. flights. Commercial carriers typically have some phone connection service with a ground medical agency, like like Medair, which is one of the biggest ones, and these have physicians on the ground that will consult with the pilots, crew, or any medical volunteers on board. For any medical volunteers that do step up to help take care of a traveler, they are protected by the Aviation Medical Assistance Act of 1998, and there has never, at least to right now, been a case of a physician volunteer on board getting sued for any type of legal complaint. So this is an example of Medair, which again is one of those big medical support companies for commercial airlines. The FAA does require an emergency medical kit with both some equipment and recommendations, so we can see kind of a variety of basic medical equipment and some injectable medications and tablets. There have been many calls for changing those, that list of both equipment and medications, and many of them are pretty common sense, so we'll kind of talk about those. The changes have been proposed by ICAO, the International Air Transport Association, ASMA. In 2019, the Air Transport Medicine Committee of ASMA also actually made recommendations with input from ASEP, AMA, and the American Academy of Pediatrics to include things like an electronic blood pressure cuff, because it can be difficult to hear the blood pressure with the stethoscope when you're in the aircraft, and then EpiPens, which makes sense. As we saw before, epinephrine is included, but if you were to be having a patient with an anaphylaxis emergency, would you want to be thinking about how to draw up your 1 in 10,000 Epi and the dose to give and into a syringe and that type of thing? So really, EpiPens do make a lot of sense, especially for the non-medical attendant. Naloxone, especially important these days, medications like Zofran, lopramine, pain meds, anti-seizure medications, and also recommendation for more pediatric formulations. All right, so our next question. Regarding the risk of DBT in commercial air travel, which of the following is most correct? So our best answer is D, the low molecular weight heparin. Okay, so moving on a brief word about space operations. So the International Space Station crews do receive continuing education on air medical issues and the physiology of space. They're all CPR and first aid trained, and prior to the mission, the flight surgeons do brief the crews on various topics that might affect them in space. You have two crew members who are trained as crew medical officers on the use of diagnostics, use of the medical kit, injections, some dental and ER procedures. The International Space Station does have health maintenance system kits based on the expanded shuttle orbiter medical system kit. So here's just a list of some various kits on board and their contents. There have been numerous types of space medical events over the years, so pretty much the range of things potentially related to space, like space motion sickness, as well as just any problems that might normally happen when you're on board somewhere for several months. Okay, now we're switching gears to talk about aeromedical transport. So we use aeromedical transport for a couple reasons, namely the speed of transport, the efficiency, and also the distance that we can go by air that we can't on the ground. So indications for medevac are pretty much that you need medical care that's available elsewhere that you don't have where you are right now and where you need to move expeditiously and when you have a stable enough patient to be transported by air. There's no absolute contraindications. It is important to have physician involvement, both offline, creating medical protocols, potentially online by some sort of phone or telemed link. This is also possible in ICU-type medevacs to have a physician on board, although this is more rare. Medevacs do have military origins. In World War II, before medevac, about 4% of wounded in action died of their wounds. In the Korean War, the helicopter started to be used, and we saw that wounded in action number decrease. The Vietnam War made extensive use of both CASEVACs and medevacs, CASEVACs being transporting injured in a lift of opportunity rather than a dedicated medical asset. And then in Iraq and Afghanistan, we really honed in and were able to really improve the CASEVAC and medevac process to really give our service members the best chance of survival. We can use really any type of aircraft, so helicopters are typically used for short-range incidents to the hospital or between hospitals. They're primarily limited to VFR, move a little slower, have lower range, and fly lower. They also do have a higher mishap rate than other types of aircraft that are used in medevacs, and they do have a higher mishap rate than non-EMS helicopters, but this is likely due to the emergent nature and taking some risks to get people out of a bad scenario. Our mid-sized fixed wing can go from airport to airport, but we do have to factor in ground transportation when we start talking about times to go from one place to another. They are able to travel more sensibly in IFR type settings, go faster, longer, and higher. The military especially has some large aircraft that are used for inter-country transfer. This includes our Air Force CCAT teams. This is typically done for non-emergent transfers. So it's important while the patient is in the aircraft that we need to have continued in-flight monitoring and care. This includes basic things like cardiac rhythms, pulse, blood pressure, pulse oximetry, hypnography, and can involve the use of some different types of equipment to kind of combat that aviation environment, such as noise-canceling stethoscopes or headphones or Doppler stethoscopes. In terms of the care teams that are involved, our point of injury team are usually very skilled EMS or pre-hospital type providers, where inter-facility care is likely more consistent with the hospital or ICU type setting and capabilities. The patients on board our MEDEVACs have the same risks as that to the aircrew with the decreased pressure, noise, vibration, acceleration, and low humidity, and we'll talk more about those. So first off, our hypobaric exposure. So this can be important both from a medical care procedures and our equipment standpoint. So we, for example, for pneumothoraces, we'd want them to be stable for a few days and with a pre-flight chest x-ray to evaluate and want our chest to fit with the Heimlich valve. For intraocular surgery, we need to make sure there's no residual gas and also evaluate whether we can fly after sinus surgery and sinus fractures. Also worry about residual gas and abdominal surgeries and then need to consider the use of something else besides air splints and glass bottles that are used for IVs. There's a couple things that we can do to potentially combat this. So some aircraft are able to increase the pressurization to decrease the cabin altitude or they could possibly restrict the altitude if the medical team is able to coordinate that with the crew. Hypoxia, also an important consideration, is again, we talked about for our normal commercial type aircraft, they go up to about 8,000 feet. So often we can just increase the percentage of oxygen to overcome what our patients are feeling, but it is important to consider our hemoglobin hematocrit. Seven and a half and 30 are the guidelines. However, these can have a poor correlation within the first few days after injury. The best predictor of having problems at altitude is a low arterial oxygen level, less than 60 at sea level. There's also something called the high or hypoxia altitude simulation test, which is a way of sort of testing what, like how a patient will do at altitude. You can give a patient 85% nitrogen, 15% oxygen, and that will simulate an 8,000 foot cabin altitude. You can also use supplemental oxygen if the PO2 is less than 55. So our other considerations that we've talked about prior. So in that closed cabin circulation, you do have dry air. It's a constrained space, meaning that there's not a ton of work or ton of space for people to work, and there's not a ton of room for the number of workers. So that might influence what you're able to do for a patient. Turbulence can also influence the care that's provided if the crew and the patient need restraints and could interfere with access to care, could cause nausea and vomiting, something to consider in a patient with mandibular wires, and then also something to consider with patient with traction weights to replace those with other types of traction. Medevacs are regulated by 14 CFR Part 135 for the most part in terms of our helicopter and unscheduled commuter fixed-wing higher medevacs. Some fixed-wing operations are under Part 121. Part 119 also provides some specific requirements for air ambulance operations. It's important to note that the regulations deal with safety of crew and operations and not of patient transport or patient care. Okay, so moving on to our next question. So the FAA rules governing transportation of patients by air. The answer is A, do not address patient care recommendations. All right, moving on to airport disaster management. This is not super well discussed in a lot of the resources, so what we'll talk about comes from a couple different places. So here's just a view. Very large airport. You can imagine what the requirements would be if you imagine a large aircraft crashing, for example, and needing to have a disaster response in this type of setting. So FAR 139.325 does require that certified airports have an emergency plan to cover aircraft incidents and accidents, as well as other natural disasters, terrorism, utility failures, etc. They have to be able to provide medical assistance and transport for the number of persons on the largest air carrier that the airport expects. The plan must be reviewed annually with tabletop exercises and exercised fully every three years. And the FAR 25.803 in Appendix J also mandates that for an aircraft, they must be able to evacuate the full passenger load in 90 seconds with half of the exits blocked. And it seems kind of impossible, but it really, it has been done. So this is an example in 2005 of an Air France jet that crash landed in Toronto, and 309 people were all evacuated in less than two minutes. Okay, so now we're actually going to see a video of the new Airbus A380 at the time that has, let's see, 555 passengers. And in this video, this was done because the airline or Airbus had to prove that it actually could evacuate all the passengers from two levels in less than 90 seconds. And everyone has to start off with their seatbelts on and the lights are all off except for the cabin emergency lighting. So really fascinating. Hard to believe that that could happen. And it is actually important that these aircraft are able to evacuate this way, and it has been done before. So this is in 2013 in Asiana Airlines, San Francisco crashed. This had resulted in two deaths, but also, you know, the vast majority of people successfully evacuated. Um, it is interesting though, we'll see a couple more pictures when you discuss evacuation with the passengers and everyone is told to left your thing, leave your things on board. And we do see that many people carried their suitcases with them. And here's an example, you know, from that flight of the injuries and the triage being performed. So many, um, lay people would think that, you know, an aircraft crash would mean that everyone does, but that's really not the case. The severity varies widely by the actual incident, but there's a number of flights that actually have a significant number of survivors, especially when they're in that, in that crash landing type scenario, like we just saw. So these are our key airport disaster services, encompassing everything from crash fire rescue, medical, police, supply, hospital logistics, transportation, and crisis intervention. Here's an example of a mass casualty plan. So we can see here's the aircraft, here's our crash fire rescue. And then this is a vehicle free zone where stretcher bearers would take the injured to the triage area here and then off to hospitals. So these are some general principles of disaster management from an excellent resource and a textbook. So you can read through these, but essentially the disaster preparedness really needs to be effective, realistic, and with a focus on planning. Okay, so when we have a disaster, also one of the more morbid things we have to think about is then what do you do with all of the fatalities? So there's disaster mortuary operational response teams or DMORTS. We have 10 regional teams that fall under the Department of Health and Human Services and the National Disaster Medical System. There's an MOU established between them and the NTSB so they can be called to assist with fatalities that overwhelm local resources. There can also be assembled portable morgues. There's three disaster portable morgue units that are maintained by the Department of Health and Human Services. Okay, our next question. Pick the incorrect statement. Okay, so our incorrect statement is answer A, which is a certified airport must have one review every three years. So they have to have a review every year with a full-scale drill every three years. Okay, so we're moving on now to selection, certification, and retention. These are just some basic factors to consider when we're selecting pilots and crew. Is there a risk of sudden incapacitation? Is there risk to self, others, equipment, and mission? Can the member perform the tasks required? Do they have the ability? Do they fit the anthros? Do they have stability and experience? And do they have the required longevity? Do they have stability of health over time? And this also considers is there a cost to train replacements? And do they have longitudinal monitoring requirements? In civil aviation, there's a wide diversity of equipment and missions. You have commercial air transport down to balloons and ultralights. There's also significant diversity in our pilot population, even with regards to education, training, experience, and health. Medical selection certification is controlled by FAA, the Federal Air Surgeon, whose Office of Aerospace Medicine is headquartered in Washington, D.C. There are nine regional flight surgeons and a military international flight surgeon that manage the regional medical offices, consult with AMEs on medical certification problems, and direct the regional AME program. There's also CAMI, the Civil Aerospace Medical Institute, with the Aeromedical Certification Division manages medical certification program, whereas the Education Division manages the selection and training of AMEs. So pilot certification requires both a medical certificate and a pilot certificate. Public safety underlies the requirement for medical certification, and when conducting these exams, there is no patient-doctor relationship. There are three different types of classes for FAA medicals. The first class are airline transport pilots. Second class are commercial pilots, flight engineers, flight navigators, and air traffic control operators. Our third class are private or recreational pilots. Pilots may apply for whatever class they want and they meet the standards for, so they do not have to have, for example, an airline job to apply for a first-class medical. Each airman can only have one certificate, meaning you can't have both a first and a second-class certificate. There are no age standards for medical certificates, but there may be standards for the type of pilot certificates, such as for the airline transport pilot, commercial pilot, and a private pilot. Private pilots being 17 years for powered aircraft and gliders and balloons for 16 years. Our first-class medicals for pilots under 40 is valid for a year and 40 and over valid for six months. Our second classes are valid for 12 months and our third class under 40 valid for 60 months, 40 and over valid for 24 months. For sport pilots, they need a third-class certificate or a current driver's license. They must not ever have been denied a third-class medical, nor have had the most recent medical certificate revoked or suspended, and they are limited to an aircraft weighing 1,320 pounds and one other passenger. For gliders and balloons, you do not need a medical certificate, but you do For gliders and balloons, you do not need a medical certificate, but you do have to certify that you do not have a known medical condition that would be unsafe. Here's a slide reviewing the different types of jobs, how certificates needed, and medical certificates required. Here's another summary of all of our validity periods for medical certificates. It is important to note that there is this kind of rollover phenomenon where after the validity expires, for example, of a first class, the pilot can perform second-class duties for however long is left. So, for example, if you are 40 and your first class expires, then you can perform second-class duties for another six months to a total of 12 months. There are different standards depending on the type of medical, and this is from the AME guide. You can see some different vision requirements here. Aviation Medical Examiners, or AMEs, the designation is covered under 14 CFR 183.21. The training consists of a course at CAMI that is also performed elsewhere, whereas office staff can have computer-based instructions, and there are refreshers required. Typical AMEs perform exams for second- and third-class certificates based on FAA standards, whereas senior AMEs can examine and certify all classes. The addition is that first-class medical. This usually requires several years of AME service, a low error rate, and some additional exam equipment. There is no set exam fee that the FAA states. Really, the exam fee is determined by the AME. So, this is the AME guide available on the web. It's a little bit more detailed than the FAA guide, but it's a little bit more detailed than the FAA guide. So, this is the AME guide available on the web. I really recommend you can, especially reading through the intro parts, have some really helpful information. And as you studied in your FAA lecture, here's our disqualifying conditions. Important to know all of these. So, airmen who are medically disqualified can be considered by the FAA for a special issuance of a medical certificate. This is the same concept as a military waiver. The applicant must show the agency that they are able to perform duties without a danger to others. This might require more testing, follow-ups, or even flight tests. They're time-limited, and the aviator must re-qualify for renewal. There is a little bit more leniency with third-class pilots. This is known as the freedom to accept risks that commercial or airline pilots do not have. There's a couple special cases that we'll talk about. So, one is conditions AME can issue, or CACIs. So, these are conditions where the AME can actually issue based on a worksheet that speeds up first-time issuances. There's also something called the AME-assisted special issuance, or AASI, where the examiner may re-issue under the provisions of a prior authorization. This is a little bit old data, but we can see that in 2010, for example, about 8% of first-class medical examiners about 8% of first-class medical holders had special issuances for cardiac history, and 7% for alcohol and other drug history. So, it is pretty common to have special issuances. So, here's our current CACI conditions, and then again about our AME-assisted special issuances. So, those are medical conditions for disqualifying. They must be deferred initially, but then once they're granted, the AME can re-issue the medical certificate once the specific criteria is met. There's many more conditions that have those AASIs. The SOTA is a little bit different. This is a statement of demonstratability. So, this is for static or non-progressive defects. So, this might be like a limb loss, loss of an eye, hearing loss. They're not time-limited. You only renew them when the condition changes. You must demonstrate satisfactory performance to an FAA inspector, though, and this may require operational limitations or even only use in specific aircraft. All certificates issued are reviewed by the FAA, and AME errors are noted. The most common error is actually training delinquencies on behalf of the AMEs. Next would be issuing a certificate while the pilot is on medications that are not safe for flight. There's a list of do-not-issue, do-not-fly medications in the AME guide. It's important to review. This certainly doesn't cover all of them, but it's a good starting point. There's also a list of temporary medications on the do-not-fly list, and these are those that cause sedation or cognitive decline. So, a pilot is actually obliged to not fly while on these types of medications for five times the half-life or five times the dose interval if the half-life is not known. So, if an AME denies a pilot a medical certificate, the pilot can appeal to the FAA, and if the FAA denies the medical certificate, they can petition the NTSB for review. This appeal must be filed within 60 days of the FAA decision. In this case, an administrative law judge hears the case, and the questions that it asks are, has the agency appropriately applied its standards? Important to note that this is not asking whether the standards themselves are appropriate. The pilot may have legal counsel and provide evidence. If the FAA acts within 60 days of an AME certifying an airman, the burden of proof is on the pilot. But if the FAA waits until after 60 days, the burden of proof is on the agency. There's no such thing as a grounding chit in the FAA. You must use due process. And subsequent appeals will go to an NTSB full board and then to the US Court of Appeals. As we can see here, you could wind up all the way at the Supreme Court. However, 99.9% of applicants are issued certificates. So it is really unlikely to have something denied if the airman provides all of the requested information. There's also some good AME information called medical bulletins that I'd recommend that you sign up for. So basic med is a law that's issued by Congress, not the FAA, and is a way to have the ability to fly, essentially getting around having to do an FAA medical exam. So you have to have a driver's license, and you have to have held a third class medical after 2006. The airman has to complete an education course and get a physical done by any physician. This, again, bypasses the FAA medical certification requirements. The basic med pilots are limited to flying aircraft with no more than six occupants, a max weight of 6,000 pounds. They have to go less than 18,000 feet and not exceed 250 knots. So talking in a little bit more of a broad scope about aviator surveillance for health conditions. So oftentimes, this can be done yearly but with differing standards depending on age. NASA actually has something called the Lifetime Surveillance of Astronaut Health, which emphasizes occupational surveillance and tailors medical examinations to the former astronauts. The military does career follow-up but not into retirement, so it's definitely possible that we might miss long-term occupational health issues. So for eligibility and certification to be able to go on board the International Space Station, the requirements are jointly established by NASA, the Russian Space Agency, Canadian Space Agency, the Japan, and European Space Agencies. So there's a multilateral space medicine board, which medically certifies all crew members for space flight on board the ISS. The crew flight surgeons from NASA and Russia monitor the missions. There's also a multilateral medical policy board, and within that, the multilateral medical operations panel that coordinate medical system support for the ISS crews. So our next question. Astronaut selection criteria include concern for the special physiologic demands of space flight. All of the following have been seen in astronauts returning from space flight except... Your answer is A, so everything except significant pulmonary function shifts secondary to microgravity. Okay, so the rest of our talk is really going to be focusing on accidents. First off, we'll talk about statistics. So air accidents account for 0.9% of 2020 fatalities in all forms of transportation. So we can see that roadway accidents make up 95% of fatalities, and then again, water, 2.1%, railroad, 1.5%, and so on. Water, 2.1%, railroad, 1.6%, air, 0.9%. This chart has a little bit more specifics in terms of our fatality rates, so we can see that from the years 2010 through 2020, and this is our US air carriers, our Part 135, and then our general aviation. So pretty rare to have fatalities in our air carriers. Slightly more common in our on-demand, but the vast majority of fatalities in the US occur in general aviation. But CAO defines an accident as an occurrence associated with the operation of an aircraft that takes place between the time any person boards the aircraft with the intention of flight until such time as all persons have disembarked, or someone is injured, killed, or the aircraft sustained significant damage. For the FAA and the NTSB, I'm subscribed to the same definition. A fatal accident is one where death occurs within 30 days of the accident. An incident is an occurrence other than an accident that impacts safety. So this could be something done on purpose. The DoD uses the term mishap instead of accident, which is pretty similar in unplanned or unexpected event involving fatality, injury, or other incident property damage. Exceptions being intentional damage, combat, testing. In the DoD, there's a few types of aviation mishaps. So flight mishaps are where there's an intent for flight and damage to the aircraft. Flight related mishaps are where there's an intent for flight, but the damage is to other property or people. So for example, a rotor wash causing damage to something on the ground. An aircraft ground mishap is where no intent for flight existed. It's important to note that the intent for flight is defined differently between the DoD and the services and the FAA. So intent for flight in the DoD means that brakes are released, your takeoff power is applied, your catapult shot has begun, and ends with taxi off the active runway or wait on wheels. Whereas again, the FAA, the definition is from the time that people board the aircraft to the time they disembark with the intent for flight. Here's our DoD mishap severity classifications. And our NASA mishap classifications, pretty similar. Okay, so we'll take just a quick look at NTSB fatal accident rates over time. So we can see here, it's broken down between our general aviation part 135, and then our part 121 is down here close to zero the whole time. So we can see here that our general aviation definitely has the highest accident rate and always has. It is interesting to note that the data and the definitions are important when you're talking about statistics. So this little blip here is actually when there was a change in definitions and part 121 changed to include aircraft with 10 or more seats. So essentially what happened is some of the biggest and safest part 135 operations became included in part 121, which unmasked sort of smaller and more dangerous operations with a higher accident rate. But then there were changes in regulations that brought those rates back down. Okay, so this graph is showing our general aviation accident rates from a little bit of a longer time span. So we're going from 1940 to 2010, and we have the dark blue is our total accident rate, our purple is our fatal accident rate. So these have declined over time, but have kind of stabilized out at about seven per 100,000 hours. The leading causes of accidents in general aviation are loss of control in flight, controlled flight into terrain, power plant systems components issues, and our fuel related or unknown is our number five. Factors that are often implicated are whether beyond the pilot or aircraft capability, unneeded low level maneuvers, effects of alcohol or other miscellaneous carbon dioxide, drugs, heart attack, et cetera. But a unifying largest single factor in general aviation fatal accidents is spatial disorientation. So this is fatal accidents in worldwide commercial jet fleets. So interesting to note that 61% of whole loss accidents and 55% of fatalities occur during only 6% of flight time during the takeoff and initial climb in the final approach and landing. And these are our top three causes of fatal accidents in that worldwide commercial jet fleet, similar to general aviation, loss of control in flight, runway incidents, and controlled flight into terrain. So just to summarize kind of what we've learned. So commercial air transportation is really the safest mode of transportation except for bus transport. As far as our accident rates, general aviation has higher accident rates than commercial taxi operations, which are higher than air transport. In the military, our fighter attack helo operations have higher accident rates than our transport aircraft. But this would make sense when you think about the phases of flight that are most dangerous. Our fighter attack and helo aircraft, they take off and they land a lot more. So they have higher rates of accidents. So there is something called the Aviation Safety Reporting System, which was begun in 1976, administered by NASA, interestingly enough, but funded by the FAA, that has a voluntary confidential reporting of safety incidents. It's completely anonymous, and it does receive a ton of safety reports. In 2022, it received an average of almost 8,000 reports monthly. The FAA does not use this information in violations for fines or penalties, but it does give, so this provides an incentive for people to report because it can't be used really punitively, but it results in identifying deficiencies and allows the FAA to put out alert messages, allows education, and also provides for research and publications. A note about airline crash worthiness. So takeoff and landing mishaps are more likely to involve crash survivability issues. So survival factors can include the amount of deformation of the cabin, structural integrity of the seats, the seat configurations, any fire and smoke propagation, lighting, the group behavior of passengers, cabin crew functions, and emergency exit access. You can see a couple pictures of inside of cabins, so you can imagine what would be impacting the people that were sitting there. There was a NTSB survivability study done on all accidents from US air carriers from 1983 to 2000, and of all accidents, a surprising 95.7% survived. Of serious accidents, almost 56% survived. Of survivable accidents, about three quarters survived, so a lot higher than what probably members of the general public would think if you said how likely would it be to survive an airplane crash. It also is interesting to note that the impact to fire ratio is two to one, meaning that trauma was actually more fatal than fire. What the NTSB took out of this was that really, the flight attendant safety briefings are particularly important because it is very possible to survive an aircraft accident if it's a survivable one, but you have to be able to get out quickly. In a survivable accident, forces transmitted to the occupants through their seats and restraint systems can't exceed the limits of human tolerance, and the structure in the occupant's immediate environment must remain substantially intact to the extent that a livable volume is provided. So essentially, this means that you have to be able to tolerate the force and the things around you can't collapse in on you if you're to survive, and then the post-crash environment must be survivable, meaning that you can't survive the impact and then be engulfed in a fire or in the ocean. So here's a graph demonstrating the fatalities in survivable accidents. You can actually see that there is a substantial amount of survivors. Our next question. Aircraft accident rates are frequently described in terms of accidents per 100,000 flying hours. What is the potential problem with comparing rates between types of aircraft and categories of aviation using this statistic? Our answer is A, using the rate for 100,000 flying hours may not provide an equal assessment of risk. And this might be because, as we have discussed, between different types of aircraft and aviation, you have different amounts of takeoffs and landings, which are exposure to those higher risk phases of accidents. I'm sorry, higher risk phases of aviation. All right, so switching gears now to accident investigation. So why conduct accident investigations? So we need to determine all the factors, human, material, environmental, which directly or indirectly contributed to the mishap. We want to help eliminate the causal factors and prevent future accidents and design recommendations. We also need to identify who is there, prepare for any potential legal action, and also ensure the safety of flight. So one of the first real great accident investigations took place on the British Comets, which were the first jet passenger aircraft with a pressurized hull. So there were a series of in-flight breakups in the 1950s, one thought to be due to storm turbulence, another potentially due to engine explosion, and one with no wreckage recovered. The accident in 1954, there were bodies recovered from the ocean that the pathologists thought were able to examine those bodies and determine that it seemed like an explosive decompression had occurred. So this led the investigators to then test the fuselage immersed in water and subject it to repeat pressure cycles, which demonstrated that there was fatigue cracking and structural failure around the windows. So these accidents were all due to a design flaw. And there's a picture of the aircraft, and then you can see all of the failure points and the propagation of those. So victim identification is extremely important in accident investigation. You have to make sure you're recovering the correct body. It's essentially the first step in determining location and possible role in an accident. It's also important for legal actions and insurance claims. Identification process includes collecting identifying information about the victims, observing identifying features, and making multiple comparisons between different sources of data. Positive factors are those which are not completely, which are not positive factors, essentially. So these are visual, seeing what the person looks like, their personal effects they may have with them, physical features, the flight manifest. And the greater number of these that match, the greater the certainty of identification. Whereas positive identification factors are fingerprints, footprints, dental comparisons, x-rays, DNA analysis, that you have a certainty that the person that you are identifying is who you think they are. These are examples of sinus x-rays, dental comparison, footprint. The medical investigator in accident investigations is responsible for collecting identification documentation, photos, x-rays, identifying features, personal items, dental records, fingerprints, footprints, blood type, and anthropometric estimates. The medical investigator on site has an important role. In an undamaged aircraft, they would be examining internal structures, the seating arrangement, ejection mechanisms, restraints, personal equipment. In a damaged aircraft, they'd be identifying any deformation that might have affected the victim and comparing it to an undamaged interior, including paint damage and surface changes, to see what might have happened and where the impacts were. It's best to leave the bodies in place until the investigators arrive. You need to also record the body location relative to wreckage and other victims and diagram all the debris patterns. Before removal of the body, you need to photograph in many different angles with the photo number, victim number, and document the photographer location and direction. After removal of a body, you need total body x-rays with a special focus on the feet, hands, and spine. Injury pattern analysis is a way of analyzing injuries at the scene of an accident to see what might have caused those injuries and if those causal factors then will help you determine the sequence of crash events. Certain injuries have certain characteristic patterns. Specifically, we'll talk about control injuries, and there may be patterns related to certain acceleration forces or interior configurations of aircraft. Head injuries are the most common cause of accident death, and you can see certain patterns with impacts to the top of the skulls and injuries to hands and feet, which could demonstrate who had the aircraft controls. Control injuries are those that help us determine who was actually flying, which is important in determining the cause of the mishap. These are impacts transmitted through the hand and foot controls that may produce certain injury patterns. Here we can see control injuries from a cyclic, and you'll notice that we have posteriorly displaced transverse fractures of the fifth metacarpal and the first metacarpal. This is based on where we are holding the cyclic, and see here the fractures. This would tell you that that pilot had their hands on the controls. Here's our control injuries sustained from a collective, which would be most typically an open fracture dislocation of the distal radius and ulna. Here you can see control injuries from cyclic, so you can see here the posterior displaced transverse fracture, the fifth metacarpal, and then the fracture also of the first metacarpal. So from the way that the pilot is holding this and the fractures that occurred, you can determine that they were the one in control of the aircraft. Here would be the control injuries from a collective, classically the fracture dislocation of the distal radius and ulna. Lower leg fractures can also tell you about who had their feet on the controls. So this bilaterally comminuted, segmental, angulated, and displaced shaft fractures that you see here has been described as being likely due to having feet firmly on the pedals and flying at the time of a crash. This is an injury pattern classically seen in World War II, called aviators astragalus, with a talus fracture from feet on the rudder bars, so you can see here this is where the rudder bars would be and then classically have this fracture. Injuries can also help you determine what might have happened inside the aircraft. So we'll note here that there's damage to the visor from the cyclic, and then there's a mark from an incisor on the cyclic, which means that the head kind of came forward and crashed into the stick here, which might make you think that there could be a failure of the inertial reel or that the restraints weren't being worn properly. Toxicologic studies are performed by the FAA for all civilian accidents, include combustion gases, carbon monoxide, and then ethanol and other volatiles, prescription over-the-counter and illicit drugs, also include blood glucose to rule out hypoglycemia, however it is important to note that post-mortem tissue breakdown can increase glucose. Brain lactic acid used to be studied also, but it's been proven unreliable and is no longer performed. Carbon monoxide can indicate exposure to combustion products before or after an accident, so baseline is usually very low carbon monoxide in a non-smoker, however if there's elevated carbon monoxide then this can indicate an exposure to fire. You can see here an autopsy evidence of smoke inhalation before death. The presence of ethanol in multiple tissue samples suggests ingestion before death, which is also important to know in an accident investigation, however we need to realize that there is such thing as artifact in that tissue, putrefaction increases alcohol level post-mortem, so essentially the bacteria can create alcohol, and so this can create levels of 0.06 and higher. The presence of other alcohols such as acetone or propanolol or acetaldehyde are good indicators that this is due to decomposition. Our best specimens though are the urine or vitreous because these should be sterile samples unlikely to have bacteria that would artificially elevate the ethanol level. So in this graph we can see the percentage of study pilots with positive toxicology findings for all drugs from 1990 to 2012 and see the steady increase here. One of the most worrisome and common findings are sedating antihistamines, so you can see those are on the rise also. Prescription medications are now found in about 35% of pilot fatalities. There are certainly, especially with our aging pilot population, many more pilots on medications. Parts 121 and 135 do require drug testing, which is spelled out in FAR 121 Annex I. All personnel involved in flight safety, in fact, need to have drug testing. This can be done pre-employment, periodic, probable cause, post-accident, and 50% random, but those random 50% may drop to 25% if industry-wide rates stay less than 1%. And there's multiple drug metabolites that are tested including marijuana, cocaine, amphetamines, opiates, and PCP. There's a similar program for testing for alcohol. All right, now we'll talk about crash survivability. So really the difference is sustained versus impact acceleration. So this difference is really important to understanding crash survival. So sustained acceleration is more than one to two seconds and typically fairly low Gs, and these primarily have cardiovascular effects such as G-lock, whereas impact acceleration is less than one second duration, has high Gs, and these have mechanical effects, meaning breaking things. So our main variables that we're worried about here when we talk about accidents are velocity and our stop and distance. So you can see here this plane comes down and stops in this space. This plane comes down and stops in this space. And so our stopping distance here would mean that there's a much more diffuse spread of the impact load and a higher chance of survival. It's important to remember that our human acceleration that we're talking about, this deals with the left-hand rule as far as understanding which are positive G-axes. So this is what we're looking at, this in red, this inertial reaction. So this is what's happening, what we're doing to the seat, and then this is what's happening to us, which is what we usually talk about. So important concept in understanding the forces on an aircrew is energy dissipation. So essentially we have kinetic energy is transformed into work. So kinetic energy being one half mv squared, work being force times your stopping distance. So we're going to go back and do a little bit of high school physics here. So our energy is conserved during this process, meaning that our one half mv squared, our kinetic energy, is then become equal to our work, our F times S. And that really is the problem here, is this force that's created. So here is our transformation of kinetic energy to work. So our one half mv squared, plane comes down, here's our distance, and then our crash force, which is the work being done. And then another picture of this potential equals kinetic equals work. So here's our potential energy up here, a ball kind of sitting still on a tower, it's falling, becomes kinetic. So this work times height, I'm sorry, weight times height turns into one half mv squared, which turns into our force times our stopping distance. So there's a couple types of accelerations that you might find in a crash. So constant accelerations. So this is where that acceleration, again, it's constant over time. This might be what you'd see in a carrier catapult shot, landing with steady braking, and a crash would be ideal for survival because it has the lowest peak g. Whereas variable acceleration, and especially triangular acceleration, this is the most commonly seen in crashes, as force increases during the impact and then decays as the aircraft structure collapses, but this results in a higher peak g. Okay, so we're going to talk about how we derive the g's that you might experience in an accident. I think it's worthwhile to at least walk yourself through this once and just convince yourself that with these basic formulas that you should know, kind of buried in the back of your mind from high school, that you can find this. So no matter what question is asked, you could take a couple of seconds with your scratch pad and be able to figure out what to do, even if you can't remember the exact equation. All right. So as we've talked about before, we have one half mv squared, so our kinetic energy, and then equals our force times our stop and distance. And we also remember that our force equals mass times acceleration. Okay, so we plug in then, replace the f's here. So one half mv squared equals ma, mass times acceleration, solve for the s, and then we get s equals our velocity squared, in this case, the changes in velocity, over two times the acceleration. So really in most of these cases, our final velocity is zero, so you can also think of that as just our final velocity squared over two times acceleration. So now we're going to plug in our formula for g. So remember, g is the ratio of acceleration over gravity, or acceleration equals our g times gravity. And then depending on the units being used, for example, in a question stem, g would either be 32.2 feet per second squared, or 9.8 meter per second squared. So if you plug in then, this a equals gg into over here, then you come up with your g's in a accident with a consistent f. So that's important to remember that this specific case is for the special case in which you have constant acceleration. And we can also show that if we want to see the time of impact, rather than the stopping distance, we can use force equals mass times acceleration, acceleration being change velocity over time, and then plug that in and come up with also an equation for time. So as we mentioned before, our mid-peak triangular acceleration is the most common. And the peak g in these cases are double our average g. So we found in the prior equation, this is the case with constant acceleration or average g. And we can see this 2 in the denominator here. So our peak g is double our average g. So that 2 is gone. And then here is the equation then for our peak g in this most common triangular acceleration crash force. And with different types of patterns, you can have different g equations, but this is the one to know. All right. So let's look at an example problem. So we have a car traveling 60 miles per hour. The front end of the car is smashing two feet. So that two feet is our stopping distance. What are the g's experienced by the driver? So we're going to assume that mid-peak triangular crash pulse. So here's our equation then, our velocity squared over g times s. So first, we have to make sure the units line up. So you change 60 miles per hour. And then change miles to feet, hours to seconds, and we get 88. And so then we have our final velocity again is 0. So we plug that into the equation with our g times 2 feet. And we come up with 100, I'm sorry, negative 120 g's. So the factors that affect crash tolerances are the rate of g onset and the pulse shape, the direction of acceleration relative to body axes, the duration, the peak g's, the seat type and restraints, the physical characteristics, secondary impacts, and force distribution. So this is just a chart where you can see some g's that we experience in everyday life, such as an elevator, 0.1 to 0.2. And then maximum attainable g's in a normal automobile, 0.7, aircraft, catapult takeoff, seat ejection. And then here is a list of selected injuries and the g forces that might cause them. So pulmonary contusion, 25 g's, aorta tears. So these are important, medial tears at 50, internal tears 50 to 80, transection more than 80. And then our vertebrae with compression fractures, starting in the 15 to 20 g range, with total body fragmentation at 350 g. So thoracic aortic lacerations are the best documented physical injury correlated with crash forces. Essentially, your heart is a bag of blood suspended in the chest cavity. And so those deceleration forces stretch the aorta and generate stresses, which are the greatest in those fixed portions. The majority of surgical cases where the person survives have injuries at the isthmus. So other locations are most likely more fatal. So here's our surgical cases where there's more likely survival. This is a documentation, or this is a graph showing injuries in early cartridge type ejection seats, but still important today because our seats work about the same as far as the forces on the vertebrae. So you can see here that the T11, T12, L1 have really high susceptibility to fractures, and these have been borne out in multiple types of accidents. And this is a graph showing Gs with a ejection seat, so you can see seat man separation and then the Gs with the, as the parachute inflates. And what's important to note here is that the Gs with ejection are at the threshold for spinal fracture. So this is why after any ejection, even if the person's walking away, there is a recommendation to get full spinal x-rays and make sure that a compression fracture hasn't occurred. So there's a researcher named Swearingen at CAMI in the 60s, did a lot of research on crash forces, primarily in automobiles, where he'd actually go to junkyards and see the crashes and then go and find people that had been in the crashes and kind of document what had happened. And so studies have had impacts in these crashes also. And we can see that in direct trauma, oftentimes will lead to depressed fractures, which is not very well tolerated by the human brain. But if you have a more compression type force, that is generally much better tolerated. It certainly can lead to tissue stretch, cavitation, and diffuse axonal injury, as well as that injury on the other side of the brain, the contracute type injury. If we add in a deformable surface, such as a helmet, this absorbs energy and conforms the surface, which really spreads the load across the skull. So it increases the stopping distance and decreases the peak Gs. So the researcher, Swearingen, did tolerances of the human face to crash impact. And so you can see the different areas of the face and the Gs that would cause them to fracture. And so we can see also that the researcher found that blows to the face of more than 30 Gs cause loss of consciousness for 15 minutes to two hours. So we need to design for less than 30 Gs to the face. And we can see here that brain concussions can happen 60 Gs for 0.02 seconds or higher Gs for even more brief periods of time. All right, a few words about restraint systems. So the purpose of restraints is to transmit the load between the seat and the vehicle structure to the occupant. It helps prevent interior collisions with the aircraft environment and also helps with positioning for ejection seats. It's important to note that a lack of adequate upper torso restraints causes significant amount of impact fatalities because of the head primarily going forward and causing an impact to the skull. So you can see here that with a lap belt only type restraint, the distance that the rest of the body and the head can go and what they might impact within the aircraft environment. Whereas if you're restrained with the shoulder harnesses, much more limited in terms of your extremities and your head location. And see here are the shoulder strap loads from those restraints and how they keep you back in the correct position. You can get up to 30 Gs protection with a three-point restraint and 40 to 45 Gs with a five-point restraint. So this really shows the benefit of using that full restraint harness and why we use them so much in aviation. The FAA also regulates the amount of Gs that need to be protected for in passenger air travel. It's really important to wear restraints properly and to not use unauthorized cushions. And this is due to a concept called dynamic overshoot. So essentially accelerations of poorly restrained occupants can actually be greater than those of the vehicle. So with looser restraints or cushions, essentially the body is delayed in decelerating until after the vehicle is already decelerated, meaning that when the body contacts the restraints, you get a sudden deceleration spike that's actually higher than that of the vehicle itself. So here's the airframe impact, and then here is the person's impact. CREEP is an important mnemonic for organizing crash survival factors. So this is just a way to remember, we need to think about the container, the occupiable space, the restraint, are they properly restrained and decelerate with the aircraft, the environment, the cabin conditions, the energy absorption, and the post-crash environment. All right, next question. Many factors exist which favorably influence the ability of the human to withstand larger decelerative forces occurring during a crash. Select the correct answer. So our answer is C, crash forces are better tolerated in the forward to backward direction. All right, well, that concludes our board review talk on aerospace management administration and operations. Please feel free to send me any emails, any feedback questions, and good luck on the exam. Thank you.

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