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My first experience as a night-flying student pilot was unforgettable. With the winter sky cold and clear, a partial moon and myriads of stars, the beauty of colorful nearby city lights made the experience not only a major step toward the pilot licensure, but also a renewed appreciation of the night sky and inestimable value of the human senses. Along with most pilots, my subsequent flying hours has nearly all occurred during daylight hours. My flight instructor strongly advised that I get an instrument rating before doing more cross country night flights. So, that is what I’m doing. Nevertheless, there is a certain mystique in night flying, with the awesomeness of the starry sky, and the extra challenge of navigation, locating airports and landing with fewer visual cues.

 Most pilots remember the FAA rules for currency when carrying passengers at night, at least three take-offs and full-stop landings during the night defined as one hour past sundown to one hour before sunrise. They must be documented within the previous ninety days, and of course described in your log book. Further, those take-offs and landings must be done in the same aircraft category, class, and type as you propose to carry your precious passengers. It is a reasonable rule, all in the interest of safety.

 The human eye works different at night than in the daytime. Millions of visual receptor cells, called rods and cones, are located in the interior of the eye on a membrane called the retina. These cells convert light into electrical energy, which is transmitted along the optic nerves to the brain, where they are integrated with memory, recognition, and motor reflexes and muscular responses. There are about seven million relatively thick cones, mostly concentrated in the central vision part of the retina, and these are principally used in the daytime, as they provide color discrimination and the skills used in reading fine detail. At night, however, the rods take over, about 120 million of them, and since they are found more peripherally in the eye, it is necessary to use off-center viewing to see your way around the plane, or to scan for other traffic when aloft.

 Except for our plane’s taxiing or landing lights, the other lighting systems – beacons, anti-collision lights, strobes -- are only to make our aircraft visible to others. Pilots could not see a thing in the sky were it not for the phenomenon of dark adaptation. That is why before a night flight it is advisable to darken the room where the pilot waits, and let the eyes adjust to darkness. The pupil will of course dilate to let in more light, while the rods become up to 100,000 times more sensitive than they were when exposed to bright daylight illumination. Since the rods cannot detect colors, it is possible to use a red tinted flashlight, and not ruin the dark adaptation of the rods for outside the flight deck scanning. However, red lighting distorts sectional chart colors, and in the cockpit it is better to use dim but white lighting. Bright light exposure can ruin this dark adaptation in seconds, making a pilot almost blind to instruments or outside dangers. All pilots are advised to carry an extra flashlight, though, and spare batteries, since there is the rare hazard of electrical failure. Though uncommon, that emergency illumination would be life-saving since the primary flight instruments, charts, and cabin details must be seen to ensure a safe and timely landing.

 Optical illusions can occur while flying on clear moonless nights, especially over sparsely populated areas. This can lead to special disorientation in the cockpit, and the high risk of an inadvertent turning stall or a graveyard spiral. Even celebrities and professional pilots are not immune to such disasters. Instrument flying, whether with a safety pilot, an instructor, or in a flight simulator can help to maintain the skills, and automatic reliance on that attitude indicator, directional gyro, altimeter, airspeed indicator, and turn and bank coordinator that will make your panel’s ‘six pack’ a life saver whenever the horizon disappears or the ‘seat-of-the-pants’ position sense proves unreliable. And this is common at night.

 Oxygen is another consideration for night-flying, especially at higher altitudes. Most GA pilots will be wise to put on the oxygen when flying over 5,000 feet MSL because of the sensitivity of the human eye to low levels of hypoxia. And, the rods are the most sensitive of these vital senses. When transitioning to landing configuration, be sure to follow the entire check-list. Gear down. Fuel on ‘both,’ or fuel pump ‘on.’ Carb heat if needed. Adjust prop. Landing lights. Radio calls, etc. Night flying demands more awareness of obstructions and obstacles. Guy wires, trees, towers, and other aircraft are all unforgiving. Collision avoidance is your job. What you can’t see could really hurt you!

 Use current navigation charts, so you can land at the expected runway, not the other airport nearby. Look at the beacon to be sure it is green and white, alternating, and not white-white-green.   And, especially don’t land on the water, unless you are a float plane or amphibian. Checking the NOTAMs can also help you with current information about your destination, especially during presidential campaigning months, when national dignitaries fly in and out of remote places with little previous warning. Look for the VASI lights, hoping that they show ‘red over white’ all the way to the TDZ.

 Most pilots know these things, but we all need to be reminded from time to time. Like our piloting safety rules, there are health considerations that similarly do not depend upon chance. Calmness under pressure is not accidental, but the result of a long series of wise decisions. Like the pre-flight and pre-landing checklists, the pilot’s nutrition is also the result of careful planning, personal insight, study, and self-discipline. Avoidance of alcohol contributes greatly to a pilot’s skill. And, the effects of an evening at the local ‘watering hole’ are not over in eight hours; even though the FAA says you are fit to fly. Tobacco use, especially smoking, is an invitation to hypoxia, and can drastically curtail visual skill, perhaps when it is most needed, like in a stormy or IMC night landing.

 Flying rested, and with adequate hydration, and without the burden of occupational or family stress, can give a pilot the alertness needed for rapid decision-making. It is the unexpected event that reveals the truly prepared pilot, and distinguishes him from the one who enters the aviation statistics or newspaper headlines. The traveling public deserves the best we pilots can offer. Our families deserve the same. Successful flying starts with a series of decisions – a good night’s sleep, a drink of water, breakfast to start the day, some warm-up stretching, outdoors for a breath of fresh air or brisk exercise, and a self-assessment concerning general health of mind as well as body, basically a pre-flight physical to be sure you are good to go. Like the night vision issues, the instrument proficiency, and the airworthiness certification, a pilot’s health is paramount to safe night flying. You will have a great experience, viewing the city lights, the brilliant stars, while enjoying the smoother air, and the extra lift that comes from lower nighttime temperatures aloft. We just don’t want to hit anything, or anybody, only the intended runway. It’s worth the effort to fly it right . . . the first time.

 Doctor Hansen is the Medical Director of the Emerald Valley Wellness Center, located in Creswell, Oregon. He has authored an extensive book of natural home remedies and, Get Well At Home. The 10-day Live-for-Health Wellness Program can help pilots with chronic diseases such as diabetes, hypertension, or heart disease regain their health and possibly pass their flight physical again. For further information, other articles, and book orders check their web site: www.emeraldwellness.com