Fatigue certainly isn't new but in the world of accident and error prevention it is newly-discovered. It used to be rare to see the word fatigue appear in an accident probable cause finding but not anymore. We could debate whether more accidents are being caused by fatigued pilots or whether investigators are considering fatigue as an accident causal factor more than they ever did. It doesn't matter. Fatigue is now being identified as a cause of errors and accidents throughout the aviation industry, and not just for pilots. Airlines are aggressively looking at fatigue in the workplace for maintenance technicians and ramp personnel.

Duty time requirements were once thought to be the cure-all for pilot fatigue. We now know that many airline pilots have commuted great distances to get to work and then, if they are lucky, caught a couple of hours sleep in a recliner in the crew lounge before even beginning their duty time. Many airline pilots, especially in the regional airlines, have to work another job to make ends meet. There is nothing presently in the regulations to prevent a pilot from working all night stacking shelves in a retail store before reporting to work for a long day of flying.

On the general aviation side, we have our own situations setting us up to fly while fatigued. It seems that everybody works more hours than ever before. Trying to accommodate a career and family responsibilities can leave precious little time for sleep and relaxation. A trip in a small airplane to attend a business meeting or family function might happen to fall at the end of a few long and stressful days. The result is a fatigued pilot.

Continuing to press on when tired was once thought an admirable trait. The macho pilot would down another cup of coffee and climb in the left seat. The wimpy pilot would delay or cancel the flight. New research has shown the consequences of fatigue are more severe than once thought. The macho pilot is now viewed as the problem rather than the solution. Leading companies now actively look for signs of fatigue and encourage pilots to stand down in the interest of safety.

We often assume that fatigue comes only from working long hours or from enduring stress. But, a review of the literature shows a long list of causes of fatigue from both a physiological and psychological perspective. Some of these causes, such as sleep apnea, are beginning to show up in probable cause findings.

We typically identify symptoms of fatigue with feeling tired or weak or having a lack of energy. But fatigue symptoms can have a very detrimental effect on decision making and reaction times as well. One listed symptom of fatigue is vertigo. That's just what we need on a single-pilot, night, IFR flight with some turbulence. Maybe some of the "loss of control for undetermined reasons" accidents really resulted from pilot fatigue.

Fatigue prevention tips include managing stress, setting a routine to get enough sleep, improving diet, getting exercise, reducing caffeine and alcohol intake, and avoiding caffeinated or alcoholic beverages after dinner.

Fatigue doesn't affect all pilots, but it's probably worth taking a hard look at ourselves to see if we have symptoms of fatigue. If we suspect short term fatigue, we should rest. Chronic fatigue is a whole different matter and should be treated by medical professionals. In any case, we would be wise to avoid flying while we are fatigued.

The FAA has prepared an excellent publication on fatigue in aviation. Read or download it here.

This was a fuel exhaustion accident but the underlying cause was pilot fatigue. The pilot and one passenger lost their lives and two other passengers were seriously injured. The airplane was a Cessna 337A and the accident occurred in New Jersey in May of 2008.

The purpose of the flight was to conduct an aerial survey along the New Jersey shore and twenty miles out over the Atlantic Ocean. The pilot and the airplane arrived for the mission a day and a half late and provided conflicting reasons for the delayed arrival. Evidence points to multiple aircraft maintenance problems in the days prior to the accident. The pilot was also an aircraft maintenance technician with inspection authorization and had been responsible for maintaining the airplane for several years. Maintenance records were incomplete at best. The most recent entry for an annual inspection was nearly six years prior to the accident.

A full day of survey work was planned but the passengers elected to conduct only half of the planned area due to the lateness of the day and pilot being tired. The aircraft main tanks were topped off with fuel prior to that flight which lasted 4 hours 23 minutes according to a GPS unit recovered from the accident airplane. No other evidence of the aircraft being fueled could be located. After that flight, the lead surveyer expressed concern to her company about the pilot's behavior while in the air and stated that she thought the pilot was incredibly overtired. The next day weather precluded conducting the survey, but the pilot enlisted the help of a local mechanic to assist in performing some work on the airplane. The following day the airplane departed at 1104 to complete the survey. Shortly after 1228, the pilot told the passengers that he would have to "break off" the survey because the airplane "was having some fuel problems" and that he needed to "go back." The passengers observed the pilot repeatedly manipulating the fuel selector handles. (The Cessna 337A has a rather complicated fuel system with long lines which produce significant delay in getting fuel to an engine if a tank is run dry. The fuel tanks were not breached in the accident. The main tanks were void of fuel, but a few gallons of fuel remained in the auxiliary tanks. Fuel pump switches were found in the off positions.) The front propeller ceased and resumed rotation several times. The pilot did not make any communication with ATC to request assistance or alert them that a forced landing was a possibility. At one point the passengers were asked to help locate an airport nearby. The airport was spotted, but the airplane impacted trees before it could be reached.

The landing gear remained extended during both survey flights, possibly indicating a known mechanical problem. Perhaps the airplane could have made it to an airport had the gear been retracted. The ELT battery was four years overdue for replacement and only indicated 0.4 volts. A replacement battery still did not produce a signal. Perhaps the ELT had been inoperative for some time. There was about a four hour delay in locating the downed airplane. The NTSB report raised the question of whether the passenger who died might have survived had he received medical help sooner. Also, the NTSB report does not state whether or not shoulder harnesses were installed or used. The airplane was manufactured prior to the shoulder harness requirement and there has never been a requirement to retrofit airplanes with shoulder harnesses. But the injuries to both front seat occupants appear to be of the nature of injuries suffered in the absence of shoulder harnesses.

Evidence indicates that the pilot was suffering from chronic fatigue. If so, his decision making would have been impaired. Most likely, he forgot to have the airplane fueled before the accident flight. He was probably switching fuel selectors rapidly in an effort to squeeze out a few more minutes of flying time. Once a tank is run dry, it can take up to thirty seconds for the fuel from a useable tank to reach the engine. That is a very long time when the engine has failed and it is unlikely that the pilot waited long enough before trying another setting. This would account for the engine starting and stopping several times as it received a quick shot of fuel from a brief time at a valid selector position. His poor decisions also included delaying discovery of the wreckage by not notifying ATC of his problem.

We should learn from this accident that shoddy maintenance will catch up with us eventually and that fatigue is a very real accident causal factor.

Click here to read the full accident report.

This Cessna 303 accident occurred in Indiana in November of 2006. five people died when the pilot became disoriented and lost control of the airplane in night instrument meteorological conditions.

NTSB photo

The pilot departed his home airport, at Atlantic Iowa, at 0502 and landed at Akeny Iowa to pick up passengers. He then departed at 0559 and flew to south Bend, Indiana where he waited while the passengers attended a business meeting. A person who worked for the FBO stated the pilot and three passengers were preparing to depart when they received word that another employee's commercial flight had been cancelled. She stated the pilot and one of the passengers left to pick up that employee on the other side of the airport. She stated that when they returned, the pilot and all four passengers departed in the accident airplane. In addition, she stated that the pilot looked tired or just ready to go home.

At 1941, the pilot contacted clearance delivery and was given a clearance for the flight. The pilot read back the clearance incorrectly and was corrected by the controller. At 1953, the pilot contacted the control tower stating he was ready for takeoff. The pilot was issued a departure heading of 220 degrees. After takeoff the pilot attempted to contact departure control while still on the tower frequency and prior to having been instructed to do so. Upon departure the pilot flew a westerly heading. The departure controller then instructed the pilot that the KNOX VOR was a 200 degree heading from his current position to which the pilot responded, "I'll look at it." Twenty seconds later the pilot radioed "South Bend approach one bravo bravo how's it looking now?" The control responded that the heading looked better and cleared the pilot direct to the KNOX VOR. The pilot acknowledged the radio call. One minute and twenty six seconds later the pilot transmitted his call sign. This was the last radio contact with the airplane.

The wreckage was consistent with a loss of control and steep, power-on descent. The NTSB report indicates that the airplane was at least 383 pounds over its maximum allowable gross weight. This may or may not have been a factor in the accident, but an overweight airplane is constantly flying closer to its critical angle of attack and is therefore less forgiving. The airplane would have been overweight even if the extra passenger had not been added, but not as severely.

The pilot was clearly fatigued and perhaps realized the weight problem but did not have the energy to deal with it. Fatigue prompts us to take the path of least resistance and in this case it was perhaps to just decide that it would be OK. Or, maybe, the pilot was tired and it never occurred to him that the additional passenger's weight should be considered. One symptom of fatigue is vertigo. The pilot was legal in terms of recent experience requirements, but was he truly proficient in night, IMC operations? A marginal pilot could easily be over tasked in these conditions and fatigue could have been the deciding factor.

Like most accidents, we can't be sure what happened, but again, we see evidence that flying while suffering from fatigue often comes to no good end.

Click here to read the full accident report.

Rochester Wings 2010, held June 18 and 19, was right up my alley this year. Most of the seminars were focused on human factors. My presentation on Aeronautical Decision Making followed a very interesting talk by Jim Lauerman, president of Avemco Insurance. I had the opportunity to talk one-on-one with Jim earlier in the day, so I already had an idea of his perspective. It was refreshing to hear him tell it straight. He said that the general aviation accident rate, contrary to what the alphabet groups say, is totally unacceptable and mostly avoidable. He also said that we are being priced out of the air by the ever increasing costs of product liability insurance that manufacturers pass on to us.

Last month in this space I encouraged everyone to speak up when they see a pilot doing something unsafe. Jim made the same point, but he went one step further. He recommended that we let others know that we would be receptive to hear about things that we might be doing wrong. In other words, we should give our permission to others to tell us how we might improve. That seems simple enough. My first reaction was that of course I would be receptive to constructive criticism and I truly believe that I would. But others don't necessarily know that, and might be hesitant. That is especially true for us older, more experienced pilots. The new kid might not say anything to one of us if he or she hadn't heard us say that we welcomed suggestions.

So let's give it a try. Let's make a point of giving our permission to everyone we come in regular contact with in aviation. And, let's make sure that we respond in a positive manner to anyone who speaks up. Finally, let's vow to seriously consider every criticism that we might receive.