|
|
|
|
NAPPF
Topics
INTRODUCTION
The standards for medical certification are contained in 14 CFR part 67. The requirements for obtaining medical certification are contained in 14 CFR part 61.
Prior to
beginning flight training, a flight instructor should interview the prospective
student about any health conditions and determine the ultimate goal of the
student as a pilot. Good advice would be to obtain the class of medical
certificate required before beginning flight training. Finding out immediately
whether the student is medically qualified could save time and money. When students with a physical limitation meet all of the knowledge, experience, and proficiency requirements, they should write a letter to the FAA Regional Flight Surgeon requesting a special medical flight test. The student’s medical file is reviewed and a Letter of Authorization or Denial is issued to the student. If the test is authorized, the student will be instructed to contact the nearest Flight Standards District Office (FSDO) and request a test. After showing that they can operate the airplane with the normal level of safety, they are issued a waiver or statement of demonstrated ability (SODA). This waiver or SODA is valid as long as their physical impairment does not worsen. Additional information can be obtained on this subject at the local FSDO. Unless otherwise limited, medical certificates are valid for a period of time specified in 14 CFR part 61. The medical certificate for a private pilot is a third class. It is valid for 3 years for those who are under 40 years of age and then it is valid for 2 years.
A
commercial pilot certificate requires at least a second class medical
certificate which is valid for 1 year.
HEALTH FACTORS AFFECTING
PILOT PERFORMANCE Regulations prohibit pilots from performing crewmember duties while using any medication that affects the pilot’s ability to operate an aircraft safely. Over-the-counter medications may also have side-effects to the point of causing dangerous reactions. Pain relievers can cover up or mask an illness that could impair one’s judgment or cause dizziness, nausea, or hyperventilation. Some medications for colds and flu may cause dizziness, blurred vision, or impairment of coordination. Bowel preparations can cause unexpected bowel activities as well as drowsiness, depression, and blurred vision. Some appetite suppressants cause excessive stimulation, dizziness, and headaches. The result of taking sleeping aids is self-explanatory. Caffeine may appear to wake a person up, but too much can cause excessive stimulation, tremors, and even palpitations. Mixing some of these can cause unexpected results. The Aeronautical Information Manual (AIM) also includes a discussion on pilot aeromedical factors.
There is
only one safe rule to follow with respect to flying and the consumption of
alcohol: DON’T. Alcohol is metabolized at a fixed rate by the human body. This
rate is not altered by the use of coffee or other popular so called remedies.
For all practical purposes, only the brain gets “drunk.” When a person drinks, the alcohol immediately begins to pass from the stomach to the bloodstream. Two ounces of bourbon will be absorbed by the bloodstream in 10 minutes, 4 ounces in 30 minutes. Alcohol is carried to all parts of the body with varying effects, but the brain is most affected. Alcohol numbs the brain in the area where our thinking takes place, then proceeds to the area that controls body movement. Coordination is affected, eyes fail to focus, and hands lose their dexterity. 14 CFR part 91 prohibits pilots from performing crewmember duties within 8 hours after drinking any alcoholic beverage or being under the influence of alcohol. The best rule is to allow at least 12 to 24 hours between “bottle and throttle” depending on the amount of alcohol consumed. Fatigue is a normal occurrence of everyday living. Fatigue is feeling tired after long periods of physical or mental strain. Some common causes are strong emotional pressure, heavy mental workload, monotony, lack of sleep, etc. Alertness and coordination suffer while performance and judgment become impaired. Anxiety is a state of uneasiness arising from fear. It slows down the learning process. Reactions vary from a person who reacts to “do something even if it’s wrong” to a person who “freezes” and refuses to act. Others may do things without rational thought or reason. Anxiety can be countered by learning to cope with fear and realizing that fear is a normal reaction. Anxiety for student pilots is often associated with performing certain flight maneuvers. Instructors should introduce flight maneuvers with care, so that students know what to expect, and what their reactions should be. Education is the best way to cope with fear of the unknown. Stress is defined as the body’s response to demands made upon it by everyday living. In flying, these stresses consist of physical, physiological, and psychological stress. Physical stress consists of such things as cold, noise, or lack of oxygen. Physiological stress consists of fatigue, poor health, lack of food, or sleep. Psychological stress consists of emotional factors such as illness in the family, personal problems, or a high mental workload during an inflight situation. Anything perceived as a threat causes the body to gather its resources to cope with the situation. The adrenal gland produces hormones which prepare the body to meet the threat. The heart rate quickens, certain blood vessels constrict and divert blood to the organs which will need it, and other changes take place. Normal individuals begin to respond rapidly within the limits of their experience and training. Many responses are automatic, which points to the need for proper training in all situations. The affected individual thinks and acts rapidly, often leading to stress overload. The pilot begins to use poor judgment which often leads to poor decision making. This leads to tunnel vision or concentrating on the perceived threat rather than dealing with all elements of the situation. In student training, the best way to deal with severe stress is to terminate the flight period, return to the airport, and deal with the problem tomorrow. In other situations, pilots need to recognize the symptoms of stress or stress overload and learn how to manage it. A good physical fitness program, proper rest, and regular meals are a good beginning. The pilot should know his/her capabilities and limitations and operate within them. Avoid stressful situations such as pressing the weather or overflying that planned fuel stop. Being emotionally upset has the same effect on a pilot as extreme stress or fatigue. There are many causes such as divorce, loss of job, death in the family, financial trouble, etc. It causes anger, depression, and anxiety. This emotion affects judgment and alertness to a dangerous degree. Don’t fly when emotionally upset.
Tobacco
ENVIRONMENTAL FACTORS WHICH AFFECT PILOT PERFORMANCE Human beings, who are designed for living on Earth, must now learn to survive in a slightly different environment. The effects of a deficiency of oxygen, changing pressures on the ears and sinuses, spatial disorientation, illusions in flight, and visual requirements require procedures and aids not commonly used on the surface. Hypoxia is a deficiency of oxygen which impairs the brain functions and other organs. As we gain altitude, the atmosphere decreases in pressure. Although the air still is 21 percent oxygen, the amount of oxygen present also is decreased as the air pressure is decreased. Night vision begins to deteriorate at about 5,000 feet MSL. From about 12,000 to 15,000 feet MSL, judgment, memory, alertness, coordination, and ability to make calculations are impaired. Some pilots might feel dizzy or drowsy. A sense of well-being (euphoria) or belligerence can occur. A pilot’s performance can seriously deteriorate within 15 minutes at 15,000 feet MSL. Above 15,000 feet MSL, the periphery of the visual field grays out to a point where only central vision remains (tunnel vision). Fingernails and lips turn blue. The ability to take corrective and protective action is lost in 20 to 30 minutes at 18, 000 feet and 5 to 12 minutes at 20,000 feet MSL, followed soon thereafter by unconsciousness. The effect of hypoxia occurs at lower altitudes with the use of some medication, smoking, alcohol, emotional stress, etc. The worst part is the fact that hypoxia is very difficult to recognize because of the gradual dulling of the senses. Since symptoms of hypoxia do not vary in an individual, the ability to recognize hypoxia can be greatly improved by experiencing and witnessing the effects of it during an altitude chamber “flight.” The FAA provides this opportunity through aviation physiology training, which is conducted at the FAA Civil Aeromedical Institute (CAMI) and at many military facilities across the United States. To attend the Physiological Training Program at CAMI telephone (405) 954-6212 or write:
Mike
Monroney Aeronautical Center Hyperventilation, or an abnormal increase in the volume of air breathed in and out of the lungs, can occur subconsciously when a stressful situation is encountered in flight. As hyperventilation “blows off” excessive carbon dioxide from the body, a pilot can experience symptoms of light-headedness, suffocation, drowsiness, tingling in the extremities, and coolness – and react to them with even greater hyperventilation. Incapacitation can eventually result from incoordination, disorientation, and painful muscle spasms. Finally, unconsciousness can occur.
The
symptoms of hyperventilation subside within a few minutes after the rate and
depth of breathing are consciously brought back under control. The buildup of
carbon dioxide in the body can be hastened by controlled breathing in and out of
a paper bag held over the nose and mouth. This is one environmental phenomenon that pilots and passengers are aware of immediately. Any discomfort can be relieved, and is not harmful if the eustachian tube is periodically opened to equalize pressure on each side of the ear drum. This can be accomplished by swallowing, yawning, tensing muscles in the throat; or if these do not work, by a combination of closing the mouth, pinching the nose closed, and attempting to blow through the nostrils.
Flying
with any upper respiratory infection, such as a cold or sore throat, or a nasal
allergic condition can produce enough congestion around the eustachian tube to
make equalization difficult. An ear block produces severe ear pain and loss of
hearing that can last from several hours to several days. Rupture of the ear
drum can occur in flight or after landing. Fluid can accumulate in the middle
ear and become infected. Adequate protection is usually not provided by
decongestant sprays or drops to reduce congestion around the eustachian tubes.
Oral decongestants have side effects that can significantly impair pilot
performance. Spatial Disorientation and Illusions in Flight Many different illusions can be experienced in flight. Some can lead to spatial disorientation. Others can lead to landing errors. Illusions rank among the most common factors cited as contributing to fatal aircraft accidents. Various complex motions and forces and certain visual scenes encountered in flight can create illusions of motion and position. Spatial disorientation from these illusions can be prevented only by visual reference to reliable, fixed points on the ground or to flight instruments. An abrupt correction of a banked attitude, which has been entered too slowly to stimulate the motion sensing system in the inner ear (the leans) can create the illusion of banking in the opposite direction. The disoriented pilot will roll the aircraft back into its original dangerous attitude or, if level flight is maintained, will feel compelled to lean in the perceived vertical plane until this illusion subsides. Any time an attitude is maintained for an extended period, the ears will try to deceive the pilot into believing that the aircraft is in straight-and-level flight.
An
abrupt head movement in a prolonged constant-rate turn that has ceased
stimulating the motion sensing system can create the illusion of rotation or
movement in an entirely different axis. An abrupt change from climb to
straight-and-level flight can create the illusion of tumbling backwards, while
an abrupt upward vertical acceleration, usually by an updraft, can create the
illusion of being in a climb. The most overwhelming of all illusions in flight
may be prevented by not making sudden, extreme head movements, particularly
while making prolonged constant-rate turns under instrument flight rule (IFR)
conditions.
A
narrower-than-usual runway can create the illusion that the aircraft is at a
higher altitude than it actually is. A wider-than-usual runway can have the
opposite effect, with the risk of leveling out high and landing hard or
overshooting the runway. An absence of ground features, as when landing over water, darkened areas, and terrain made featureless by snow, can create the illusion that the aircraft is at a higher altitude than it actually is. Rain on the windscreen can create the illusion of greater height, and atmospheric haze can give the illusion of being at a greater distance from the runway.
Lights
along a straight path, such as a road, and even lights on moving trains can be
mistaken for runway and approach lights. Bright runway and approach lighting
systems, especially where few lights illuminate the surrounding terrain, may
create the illusion of less distance to the runway.
Motion
sickness is caused by continued stimulation of the inner ear which controls the
sense of balance. The symptoms are progressive. Pilots may experience loss of
appetite, saliva collecting in the mouth, perspiration, nausea, and possible
disorientation. The head aches and there may be a tendency to vomit. If allowed
to become severe enough, the pilot may become incapacitated. When suffering from motion sickness, open the air vents, loosen clothing, and use oxygen if available. Try to keep the eyes focused on a point outside the airplane and avoid unnecessary head movements. Terminate the flight as soon as possible.
Carbon
monoxide is a colorless, odorless, and tasteless gas contained in exhaust fumes.
When breathed even in minute quantities over a period of time, it can
significantly reduce the ability of the blood to carry oxygen. Consequently,
effects of hypoxia occur. A pilot who detects the odor of exhaust or experiences symptoms of headache, drowsiness, or dizziness while using the heater should suspect carbon monoxide poisoning, and immediately shut off the heater and open air vents. If symptoms are severe, or continue after landing, medical treatment should be sought. Decompression Sickness After Scuba Diving A pilot or passenger who intends to fly after scuba diving should allow the body sufficient time to rid itself of excess nitrogen absorbed during diving. If not, decompression sickness due to evolved gas can occur during exposure to altitude and create a serious inflight emergency.
The
recommended waiting time before going to flight altitudes up to 8,000 feet MSL
is at least 2 hours after diving and at least 24 hours after diving which has
required controlled ascent. The waiting time before going to flight altitudes
above 8,000 feet MSL should be at least 24 hours after any scuba dive. For more
detailed information, contact your Medical Examiner. Of the body senses, vision is the most important for safe flight. Major factors that determine how effectively vision can be used are the level of illumination and the technique of scanning the sky for other aircraft. Under conditions of dim illumination, small print and colors on aeronautical charts and aircraft instruments become unreadable unless adequate cockpit lighting is available. Moreover, another aircraft must be much closer to be seen unless its navigation lights are on. In darkness, vision becomes more sensitive to light, a process called dark adaptation. Although exposure to total darkness for at least 30 minutes is required for complete dark adaptation, the pilot can achieve a moderate degree of dark adaptation within 20 minutes under dim red cockpit lighting. Since red light severely distorts colors, especially on aeronautical charts, and can cause serious difficulty in focusing the eyes on objects inside the aircraft, its use is advisable only where optimum outside night vision capability is necessary. Even so, white cockpit lighting must be available when needed for map and instrument reading, especially under IFR conditions. Dark adaptation is impaired by exposure to cabin pressure altitudes above 5,000 feet MSL, carbon monoxide inhaled in smoking, from exhaust fumes, deficiency of Vitamin A in the diet, and by prolonged exposure to bright sunlight. The pilot should close one eye when using a light to preserve some degree of night vision.
Excessive illumination, especially from light reflected off the canopy,
surfaces inside the aircraft, clouds, water, snow, and desert terrain, can
produce glare, which may cause uncomfortable squinting, watering of the eyes,
and even temporary blindness. Sunglasses for protection from glare should absorb
at least 85 percent of visible light and all colors equally, with negligible
image distortion from refractive and prismatic errors.
Hypothermia · You’re out winter camping. You are well equipped for the experience and well dressed. The air is bitterly cold and there is an extreme wind. You start to feel sore and you start to shiver. The fact of the matter is anyone can get hypothermia even
on a sunny slightly cool day. The very young, the very old, people with
metabolic disorders, people with Parkinson's disease, severe arthritis, who have
had a stroke and people on certain medications are at higher risk of getting
this life threatening condition. Everyone in their lifetime has experienced
being cold and feeling a chill. We get goose bumps and our teeth chatter, our
limbs ache and we feel a little sleepy. Most of the time a little jumping in
place and a warm drink is all it takes to get warmed up. Hypothermia is more,
and can be serious trouble. The Federal Air Surgeon’s
Medical Bulletin, Spring 2000: Dehydration and the Pilot, lists rehydration
procedures. They advise drinking cool water and not to rely on the thirst
sensation as an alarm. To encourage drinking more water they recommend adding
some flavoring to it and caution against excess caffeine as it is a diuretic.
Their final message is to “Fly safe and never pass up an opportunity to have a
fresh glass of water.” I would like to add—with electrolytes!
|
Send mail to
info@nappf.com with
questions or comments about this web site.
|