I open my eyes and stare at the bedside clock; now it’s 2:16 a.m., and I just can’t sleep any longer. My body is telling me to get up and out of bed. It’s after 10 a.m. back in Los Angeles and well past my normal wake-up time of 6 a.m. at home. After two cups of coffee and some oatmeal, I’m feeling better and head down to the gym to work out. I’m usually the only one exercising at three in the morning, but I do see other pilots in the gym from time to time.

International long-haul flying is difficult, no matter how you look at it. We traverse multiple time zones flying westward chasing the sun, making for brutally long sunny days, or fly in the opposite direction, creating the world’s shortest nights. Flying far south presents its own problems, too. As an example, I’ll sometimes take off from Los Angeles for Sydney in the dark and land before the sun comes up after being aloft for 15 hours.

That extended darkness affects how our bodies react to jet lag, wreaking havoc on our circadian rhythms, our natural sleep time in a 24-hour period. For most of us, this lasts from when it gets dark outside, plus or minus a few hours, until waking up, a few hours from sunrise.

Flying a sophisticated jet airplane requires a great deal of concentration, discipline and experience. To accomplish these complicated tasks with precision, pilots need to be well rested and alert. Long-haul international flying poses several challenges to reporting for work rested and alert, so much so that the FAA modified old rest rules to more adequately address the physiological aspects of sleep and rest. Those old rules looked at pilots much like the machines we fly instead of considering us as human beings. The new rules were crafted after years of research by NASA into the physiology of sleep and the effects of not getting enough of it.

Sleep is a vital physiological function. While the average person can go weeks without eating, drinking water and getting sleep are mandatory after just a few days without. Research has linked fatigue to a degradation in mental abilities and the performance of even the simplest tasks. In an endeavor like operating heavy, complex aircraft, it is essential for everyone’s safety that pilots are well rested.

Because we depend so heavily on CRM (Crew Resource Management), it’s easy to see how fatigue can affect us so negatively. NASA fatigue studies have highlighted common problems aircrews encounter after becoming sleep deprived. When we get tired we’re less likely to interact socially, affecting our ability to maximize our CRM skills. Fatigue also lessens our ability to reason logically, negatively affects our mood and often leads to a loss in focus or attention. Other lapses associated with fatigue include degraded timing and accuracy in selecting control systems. We tend to accept lower standards of performance as well and lose the ability to integrate information so that even small tasks become difficult to perform. A lapse in any one of these factors at an inopportune time could spell disaster. Bottom line: Fatigue makes us lose our resolve. That’s why the rest rules required an overhaul.

Fortunately, the Air Line Pilots Association (ALPA) has been a crucial advocate in communicating the necessity for favorable rest facilities for pilots, both in the air and on the ground. International flyers will attest to all the different types of rest seats they’ve seen pilots using, depending on which airline they’re flying. Most of the legacy carriers that fly long-haul routes have dedicated bunk rooms or special lie-flat seats for pilots in first class, while lesser-known carriers might have coach seats set aside for pilots. I don’t know about you, but I have a difficult time just sitting in a coach seat (I’m 6’3″), let alone getting any rest in one. This disparity in rest facilities led the FAA to mandate a minimum standard so those airlines that don’t comply will have their crew duty times reduced considerably.

ALPA has helped in the selection of layover hotels as well. Pilots at my airline cannot be housed anywhere near elevators or ice machines or in rooms adjacent to loud street noise. It may appear trivial, but those little disturbances can create big problems in getting a good night’s sleep.

As professional pilots, we must report for duty ready. It’s up to the individual pilot to admit to being fatigued if he or she has not gotten the proper amount of rest, and therefore is unable to report for duty. We owe it to our company, ourselves and, most important, you.

Cockpit Conversation

Chris Cooke answers questions about air travel, from a pilot’s perspective.

Why are some landings smoother than others?

The difference between a smooth and a hard landing comes down to the rate of descent at touchdown. If your pilot judges his rate of descent with the timing of the flare (raising the nose of the aircraft) properly, the landing will probably be smooth. If the pilot flares too late, the rate of descent will be excessive and the airplane will literally smack into the ground.

A high flare can also cause a rough landing because the aircraft will literally stall and fall heavily onto the runway. Often, as a pilot transitions to a bigger or smaller airplane, his familiar sight picture will change, making smooth landings difficult until he has an idea of “where his wheels are.”

This Executive Travel story appeared in the October, 2014 issue of Fortune.