9 Physiology
Skim Chapter 17 in the Pilot’s Handbook of Aeronautical Knowledge. There’s a lot here that only applies to pilots in airplanes at altitude. As you skim, ask yourself if this would affect someone on the ground. If so, that’s where you want to focus.
This should be obvious: If you are on drugs, been drinking, stressed out, distracted or so tired you can barely think, don’t fly your drone. Each one of these are clear causal factors in crashes and affect your ability to safely pilot the aircraft. But the FAA wants you to know exactly how these things affect you, so here goes.
Most pilots must have a valid medical certificate to fly a plane, a certificate issued by an FAA approved doctor. Drone operators DO NOT have to have a valid medical certificate.
9.1 Dehydration and heat stroke
- Dehydration: A critical loss of water from the body. Can be caused by heat, wind, humidity and diuretic drinks like coffee and alcohol. Common signs: headache, fatigue, cramps, sleepiness and dizziness. All will degrade performance of tasks. The solution is to make sure you’re drinking enough water for the given situation. Drone pilots are going to be outside, in the sun, heat and wind. Part of your load out kit should be sunscreen and cold water.
- Heat stroke: Caused when your body no longer can regulate temperature. The early signs are similar to dehydration, but can result in complete collapse. Solutions are to first ensure adequate hydration and then getting to a cool place to recover. Heat stroke is no joke.
9.2 Drug and alcohol use
- Alcohol: When you are flying, you are making many decisions quickly. Alcohol degrades your ability to make those decisions. It impacts your mental and physical abilities, including vision, memory, fine motor control and others. Remember the saying: Eight hours, bottle to throttle. If you have been drinking within the past eight hours, do not fly. If you are hung over, do not fly. You are still being affected by alcohol if you are hung over.
- Drugs: This doesn’t need to be said, but illegal drugs are bad for flying. Just say no.
9.3 Prescription and over-the-counter medication
- FAA regulations prohibits anyone from acting as a member of a flight crew under the influence of any medication that affects the body in any way that could affect safety. There is no public list of medications that the FAA considers to be harmful to safety. They tell you to seek out an airman medical examiner in your area and ask them.
- Pain relievers, like Tylenol, Advil, etc. are considered safe. Pain killers, like oxycodone, are not.
- Stimulants, like appetite suppressants or energy pills, can cause anxiety and mood swings and are considered dangerous for flying.
- Depressants, including tranquilizers, motion sickness pills and some decongestants/antihistamines, can lower blood pressure and degrade performance. Some are considered unsafe, some aren’t. If you are taking them for allergies, for instance, you need to consult an AME.
9.4 Hyperventilation
Hyperventilation occurs often in response to stress, when breathing rate increases subconsciously. Rapid, shallow breathing leads to an abnormal loss of carbon dioxide from the blood. While rarely incapacitating, hyperventilation can cause visual impairment, lightheadedness or dizziness, tingling, hot or cold feelings, muscle spasm and unconsciousness.
The way to deal with hyperventilation is to get your breathing back under control. The most commonly known solution is to breathe into a paper bag. If one is not around – which is often the case – speaking normally helps to regulate breathing. If the visual observer or PIC begins to show signs of hyperventilation, have them talk normally. Induce them to talk. Symptoms should subside.
9.5 Stress and fatigue
Stress: When demands are placed on a person, both physical and mental, the body’s response is called the stress response. That response can include the release of hormones and increases to metabolism, heart rate, breathing, perspiration and blood sugar. Stress is divided into two types: Acute and chronic. Acute stress is an immediate threat or stressor, and most healthy people can deal with it. Chronic stress is a long-term stress that overwhelms the person’s ability to handle it. Think major life stress: death, divorce, job loss, etc. Those levels of stress can degrade performance substantially. A person suffering from chronic stress should not fly.
Fatigue: Among the most common factors in pilot error. Fatigue affects attention, concentration, coordination and communication. There are two types of fatigue: mental and physical. Mental fatigue comes from prolonged stress or mentally demanding work. Physical fatigue comes lack of sleep, exercise or physically demanding work. And fatigue, like stress, falls into two categories: acute and chronic. Acute fatigue can affect timing and vision, and can be mitigated with proper sleep and diet. Chronic fatigue usually requires treatment from a doctor. Signs of chronic fatigue are long term weakness, tiredness, breathlessness, irritability and headaches.
If suffering from acute or chronic fatigue, do not fly.
9.6 Factors affecting vision
Vision, given that all Part 107 flights have to be within line of sight, is extremely important for safe flight. Any UAS pilot should have their eyes checked by an optometrist regularly.
The PHAK describes the mechanisms in your eyes responsible for vision. The most important is that the bulk of those mechanisms are focused on the center of your vision – where you see most things – and not at the periphery. You should rely on the active vision part of your eyes more than your peripheral vision.
The bulk of vision issues common to aviation happen in places or situations that won’t affect drone pilots on the ground. Fully two-thirds of the vision issues in the PHAK are night vision issues. Part 107 operations do not allow night flight without additional safety gear.
9.7 Fitness for flight
It is the pilot in command’s responsibility to determine whether he or she is fit to fly. If the pilot is on any medication that could affect performance, or has had alcohol within 8 hours of the flight, or is experiencing any physical condition that could affect safe operations, they should decline to fly.