the eyes. This occurs as light from the sun or other source is reflected off a propeller or rotor blades or interrupted in the same cycle by the props. The rate is about 4 to 20 cycles per second and can produce unpleasant and potentially dangerous reactions.
Nausea, vomiting, and fatigue can result. In extreme cases, in highly susceptible pilots, neurological reactions occur, such as convulsions and changes in levels of consciousness. The pilot who suffers from the previously mentioned disabling conditions is also at higher risk. There is a great deal of anecdotal information but little scientific data to confirm a frequent occurrence of “flicker vertigo.”
MOTION SICKNESS
The vestibular system appears to be the source of the symptoms of motion sickness (airsickness). People who do not have functioning semicircular canals as result of a birth defect, surgical removal, or disease do not experi- ence this problem. Any pilot, subjected to the right combination of unusual attitudes or flight conditions, can become airsick. In other words, if the ves- tibular system can be “tumbled” in a way to which the pilot is not adapted, especially when there is a conflict with visual inputs, then he will become sick. There is no doubt that currency, self-confidence, and familiarity with the aircraft and its typical maneuvers is the best deterrent to air sickness.
Passengers (or pilots not in control of the aircraft) are easy subjects. New pilots are also susceptible. Some of the additional common causes include Figure 8-16 This shows the potential effect of unfamiliar terrain upon the approach slope that is flown. A normal approach over trees of familiar size (top). Unusually small trees underneath the approach path make the pilot think the aircraft is too high, so he or she makes the approach lower than usual (bottom).
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heat discomfort, anxiety, observing or smelling someone else who is airsick, and eating foods that are nauseating.
Symptoms
Nausea and vomiting are the most common symptoms of motion sickness and are experienced in varying degrees. Often a slight queasiness is noticed, but the fear of becoming sick is all it takes to become sick. Even after vom- iting, nausea often persists. One then becomes apathetic, not really caring about what’s going on. A headache and perspiration are also common. At best, someone who is airsick is impaired.
Treatment
Most people know if they are prone to airsickness. Even so, there is no known prevention technique or adequate treatment to help. Much research is being carried out because motion sickness is a prime concern in space travel. Some suggest that there is more chance of becoming airsick if one flies on an empty stomach; therefore, one should eat simple foods that he or she knows can be well tolerated. This includes adequate fluids.
Various medications are available over the counter and prescribed; however, there is little reliability or predictability from one person to another. Side effects from commonly used drugs do occur, especially over-the-counter medications containing scopolamine. The best tactic is to work with your flight surgeon, trying different combinations of diet and medications, along with awareness of current studies on prevention and treatment of motion sickness. If you frequently have problems, learning biofeedback techniques and “desensitization” have proven to be effective. Training to help pilots break the cycle of airsickness is becoming more popular. Check with flying organi- zations, for assistance.
SIMULATOR SICKNESS SYNDROME (SSS) SSS is a disorder of orientation identified as secondary to prolonged times in a full motion simulator, resulting in nausea (but no vom- iting), dizziness, visual disturbances, disorientation, and ataxia (unsteadiness and lack of postural orientation). Unique to SSS is that symptoms can occur an hour or more after leaving the sim and last for 1–2+ hours. Sim instructors are more at risk. There is concern about the use of such “real time” simulators as to whether or not such reality is justified to reach the goals of effective training. Flying a line trip soon after a sim ride is hazardous.
GOTCHA!
9
Self-imposed medical stresses
Joe knew he shouldn’t have accepted the flight. It was the middle of the night, he had been in bed two hours, and the air cargo mission he had been assigned could wait a few hours anyway. But then, if he didn’t take the job, someone else would. Oh well, a couple of cigarettes and a dose of coffee and he’ll be ready to kick the tires and get airborne. Once in the air, Joe decides to fly direct from Chicago to Dallas at 11,000 feet. Too bad he doesn’t have any supplemental oxygen on board. Then he misses a frequency change and has to be reminded of a course correction. He finds it increasingly difficult to hold it straight and level because the auto- pilot isn’t working. As the trip drones on, he becomes lethargic and keeps up with the cigarettes and coffee, trying to stay awake. Joe never consid- ers his hypoxic condition at that altitude and doesn’t care anyway. Only after he bounces the aircraft several times on his landing does he realize that he is impaired.
MANY THINGS ABOUT OUR HEALTH and safety are uncontrollable: tem- perature extremes, illness, noise, weather, and the like. We do have control in several areas, in actions we do to ourselves that we don’t have to do but that could affect our performance. Our safety is compromised as a result of how we abuse our health or live the unhealthy lifestyle we choose to live.
This includes playing doctor: making a self-diagnosis of a medical problem and then using self-medication. Also, subjecting ourselves to extremes of alcohol, nicotine, caffeine, and other easily obtained “abuses” can only impair our body’s functions and our mind’s capability to fly safely. They are self- imposed. That is, it is not required or even expected that we go beyond mod- eration in any of these areas. We choose to do these things to ourselves until our body rebels—CRISIS MANAGEMENT!
This chapter will cover each of these issues and describe in a general sense how they affect us. The other topics that are covered in other chapters are inherent to flight, but they, too, add stresses to our performance. These self-imposed stresses are not inherent, but they can complicate a tenuous flying situation to the point of being unsafe, even without problems typically associated with flight. For example, medications, as well as the conditions for which they are taken, can interfere with visual and auditory perception, decision making, judgment, and other mental processes, as well as our flying skills.
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Although all drugs and medication, whether prescribed or over-the-counter (OTC), are evaluated for safety by the FDA (Food and Drug Administration) before they are released for sale to the public, very few are evaluated as to their effect on performance in a flight environment; therefore, there is little scientifically proven insight about how any illness, medication, or habit will affect the pilot during flight. More and more data will be coming from the scientific community as a result of the recognition of human factors and flight physiology as an important part of safety. But studies are not necessary to prove what we already know from experience: These self-abuses will affect performance at one time or another.