Taking Care of the Human Element

It was 19.7 hours of single-pilot IFR spread over three days, most of it between 8,000 and 10,000 feet, dodging cumulus buildups. I experienced dense morning fog, afternoon thunderstorms, and made a timely weather divert with the help of incredibly helpful air traffic controllers.

Most of my local flying where I live in North Florida occurs in the morning or early evening, well below 5,000 feet, and averages less than an hour and a half per flight. The Oshkosh trip reminded me that a full day in the air takes a toll on the human body and can have a significant impact on a pilot’s ability to make sound decisions.

Charles Lindbergh wrote eloquently about this in his autobiographical account The Spirit of St. Louis. He recognized that the human endurance demands present during his 33.5-hour flight from New York to Paris, after just a few hours of fitful sleep, presented him with one of his greatest challenges.

A good place to start understanding these challenges is with our fellow military and commercial aviators. They do this kind of long-distance flying day in and day out. 

Unlike those of us in the FAR Part 91 universe, our Part 135 airline pilot colleagues are governed by a strict set of crew duty rules that define the maximum number of hours a pilot can fly in a day, month, or year, and place limits on flight time, duty periods, and required crew rest. For the long-haul flyers, additional pilots are added to the crew, and scheduled crew rotations and rest periods are briefed before the flight.

Military pilots have similar rules to go by, although they tend to be a bit more flexible. Like the airlines, extra crewmembers are added for long endurance flights. However, along came the billion-dollar B-2 Stealth Bomber, with no space for a third pilot. So, the Air Force spent a significant amount of time and resources developing a crew nutrition, hydration, and awake/sleep profile for each of these 30-plus-hour missions. The taxpayers will be pleased to know that the resting crewmember sleeps on a folding cot, just like the ones you can buy at your local Walmart. 

Down here in GA land, we do not have these sorts of detailed policies and procedures. Our crew duty day is left to our good judgment. Extra crewmembers tend to be our family or our next-door hangar neighbors, and our long-distance flights are generally infrequent. This last point is important. Airline and military pilots who fly long days on a regular basis have learned how to manage their on- and off-duty time as well as sleep, exercise, and nutrition. On the other hand, most of us single-engine piston jockeys spend our time on one- or two-hour hops, often for breakfast or lunch, punctuated by the once or twice a year one- or two-day trip. These longer trips, which often require many critical decisions, require a little more attention to the human factor.

First on the list is the little matter of fluid intake. Let’s face it, the biggest time penalty on a long trip are the stops along the way. Two three-hour legs are quicker than three two-hour legs every time. Given enough fuel capacity, four hours is even better at reducing stops along the way. To prepare for that much time in the air, many pilots will significantly reduce their consumption of fluids before and during the flight. The bad news is that our body tends to get used to our normal hydration levels and rewards us with lethargy, mental confusion, headaches, or worse when our internal H₂O dipstick reads empty.

There are better options. First, reconsider those shorter legs and simply decide that the one-day trip is really a two-day trip. Second, and this is sure to be controversial, drink water instead of tea or coffee. Our bodies are designed for the former and tolerate the latter. Finally, plan on consuming most liquids just prior to the last hour of the flight or whenever you feel dehydration coming on, so you are hydrated properly when the big decisions have to be made, and the FBO’s restrooms are in sight. 

Pilots seem to be divided into two camps. First are the early risers who are out the door and chipper at 5 a.m. Then there are we night owls who watch the late show and dread the alarm clock in the morning. The good news for the early risers is that most long aviation adventures seem to start around dawn, so these hardy souls are rested and ready.

Our late sleepers, not so much. Deviating from our normal sleep pattern can induce significant levels of fatigue that may cloud judgment and lead to poor decisions. And as Lindbergh discovered, sleep debt is cumulative. The time and quality of sleep you get the week before a long flight can seriously help, or hurt, alertness and decision-making abilities. 

What to do if your eyelids start drooping and you start missing those radio calls? Land for the night! And spend a few extra bucks on accommodations that promise a good night’s sleep. I have slept in the FBO’s pilot lounge, in a seedy motel that was the only one available, and in a tent under the wing during a storm. None of these provided the rest required for a full day in the air, so plan conservatively and appropriately. 

Your trusty 30-year-old Cessna is air-conditioned, right? Not so fast. Most of us have to settle for that little storm vent, an open window, or a cabin vent system designed in the 1950s. I have noticed that as I have gotten a bit older, my tolerance to heat is a bit more critical. However, heat exhaustion, which is helped along by its sibling, dehydration, can strike at any age. Heat exhaustion can creep up on you. Its symptoms are worse than simple dehydration and may lead to bad decisions and poor pilot performance. 

And how about cold-weather operations? I spent the better part of 11 years flying out of airports located within 50 miles of the Canadian border, and the effects of severe cold, especially during preflight, ground ops, and takeoff can lead pilots to hurry and miss important steps. Carbon monoxide is an ever-present concern, and all aircraft heaters are not created equal. So, what is a pilot to do? Dress for the heat or cold, hydrate, and anticipate the effects. In flight, when the fatigue comes on, it is time to land, hydrate, rest, and decide if it’s time to call it for the day. 

On a hot summer afternoon, it is not uncommon for an IFR or VFR on top flights to climb to 10,000 feet or higher to stay clear of the buildups. The good news is that the air is smooth, and the cabin is cool. The bad news is that the longer we stay at these altitudes, the lower our blood oxygen level drops. Each of us is different in this regard. If you live at 6,000 feet in Denver, 10,000 feet is less of a problem. However, if you call Key West, Florida, home, 10,000 feet is really high! Spend too much time at altitude, and your blood oxygen level can be reduced significantly. 

Back in my Air Force days, our cabin altitude was generally 8,000 feet. However, the oxygen mask that hung off our helmet supplied a readily available dose of 100 percent oxygen, and we were required to use it during critical phases of flight. Problem solved! These days, I keep a pulse oximeter handy and a can of that compressed air that you can find in any pharmacy. If my blood oxygen level drops below 90 percent, a few deep breaths from the canned air will restore it, and I feel much more alert. 

Staying alert in the air can depend on how much blood flows to your brain. My very unscientific analysis tells me that your bloodstream may have to choose between digesting your lunch or helping your brain figure out how to fly the airplane. Back in the day, the flight kitchen produced box lunches complete with large submarine sandwiches. After I gobbled one of these gut busters, I spent the next hour fighting the fatigue monster. An alert flight surgeon clued me into smart snacking to keep the blood flowing evenly to the brain and stomach. My favorites these days are energy bars, crackers, and other small snack items at regular intervals.

You knew this was coming. For the 30-something pilots out there, you seem to stay fit through daily living, so enjoy it while you can. For us older types, a regular exercise routine can develop our aerobic capacity and muscle tone. Pilots who  exercise even a little tell me they sleep better, seem to process oxygen more efficiently, and at the end of a long day of flying are more alert and make better decisions. Hmm, I just might have to get up off the couch and try that? 

The real trick is recognizing when all of these human factors try to gang up on you. Planning to address the human factors present during that trip to AirVenture will keep you on top of your game as you merge with the traffic at Ripon and Fisk. On the other hand, if you are tired, “hangry,” dehydrated, frozen, overheated, mildly hypoxic, and out of shape, be thinking about getting on the ground and staying there. As the saying goes, “It is better to be down here wishing you were up there, instead of up there, wishing you were on the ground.”