Pressure Cooker

"Pilot error" once was a term used by investigators when they couldn't find any suitable explanation for an aircraft accident. But in today's world of CVRs and FDRs, we're learning that the human factors that contribute to aircraft accidents are far more complicated than anyone imagined. Today's pilots operate in a pressure-cooker atmosphere that provides precious little margin for error. This article explores some of the reasons we make the mistakes that result in accidents.


 Some pilots who hear the term "humanfactors" dismiss whatever comes afterward because they think it is all a bunch ofpsycho-babble. But if you take the time to think about aviation accidents it doesn’t takelong to realize that every one of them has some form of human input — whether the resultof actions by the pilot, a controller, a mechanic, or a line crewman.

Years ago the term "pilot error" was used whenever investigators could notfind a suitable explanation for an aircraft accident. Most of the time the pilot was notaround to defend himself, so there were few unexplained accidents. Even today it is astandard phrase that is used by those who fail to understand that it is much too broad inits application.

Flight Data RecorderWith the advent of cockpit voice recorders at thebeginning of the jet age investigators began to realize that pilots were at fault for themajority of the accidents, but they realized that the term pilot error was a misnomer thatexplained little. The human factors that contributed to airborne accidents and incidentswere much more complicated than anyone imagined.

Cockpit voice recorders are not installed on light general aviation airplanes, so it isnot as easy to come to terms with the cause of an accident where a CVR is recovered. But athorough investigation of the circumstances usually will result in a probable cause thatmakes sense.

Why Do We Screw Up?

Though many pilots bristle at the findings that their fellow airmen inadvertently orintentionally screwed up, the truth is that pilots do some stupid things in airplanes.Why? That’s the question that often goes unanswered, and the only way to prevent similaroccurrences is to try to analyze the accident thoroughly, from a pilot’s point of view.

Piper MalibuSome accidents are the result of a pilot’s not having the skill level that we expect ofhim or her. For example, the failure of a vacuum pump in a single engine airplane duringinstrument flight should not lead to a loss of control, but often it does. I remember onefatal accident that occurred where the airplane was equipped with a stand-by vacuumsystem, but the pilot failed to engage it.

Another common type of accident is fuel exhaustion. Most often than not a pilotinvolved in a fuel exhaustion accident intentionally continued beyond what could bethought of as a reasonable and safe use of his fuel resources.

Today’s pilots live in a pressure cooker atmosphere. On the one hand there is the FAAbanging an iron gavel that few have the resources to fight, despite the publicmisconception that all pilots are rich. On the other is a relaxation of training standardsthat has occurred over the years in an attempt to turn around the decline in the pilotpopulation. You would think that the atmosphere would increase the awareness level ofpilots and their will to complete each flight safely and without incident.

Don’t We Ever Learn?

Quincy IL CrashYet the same kinds of accidents continue to occurmonth after month and year after year. That is why it is important to look intimately intothe human factors that lead to accidents and make as many pilots aware of the pitfalls aspossible. Some are not interested. These "macho" types can do anything, andoften they do, bending the metal and flesh because they neglected to consider thefoolishness of what they were doing.

Some human factors are easily understood. For example, fatigue has no place in thecockpit, yet many pilots fly without regard to the length of their day or the need forrest. Fatigue itself can be the cause of an accident or it can contribute to a pilot’sfailure to act reasonably when a system failure or emergency situation exists. In eithercase the results are not to our liking.

To be sure there are other physiological afflictions such as hypoxia, stress, illness,and physical conditioning. Pilots must train to recognize physiological symptoms andremain out of the cockpit when they are suffering from any of them.

Personality traits are liable to lead to other preventable accidents. Too often pilotsfail to recognize the change of attitude that is needed when one straps himself or herselfinto the cockpit. Flying an airplane requires much more mental activity than most thingswe do. The pilot must be constantly aware of what is going on inside and outside of thecockpit. It is those who don’t develop a solid awareness level, and those who disregardthe indications of trouble on the horizon (how much fuel is left versus time and distanceto the destination is a good example) who wind up in trouble.

Those who take risks on the ground are likely to do the same in the air. But anytimethe safety of flight is disregarded for any reason, the mental acuity must be even sharperif an accident is to be prevented. But too often pilots don’t understand the ramificationsof the actions they are taking.

Weight and balance is one of those areas that pilots frequently fail to give goodmeasure. Too often they will pack their airplanes as long as there is space without regardto the weight of the people and baggage they are cramming in there, or how it willinfluence the center of gravity. Some pilots only do half of the weight and balanceequation, totaling up the weights of people, fuel, and luggage, but neglecting to insurethat the load will fall within the aircraft’s c.g. limits.

Is Training The Answer?

Often we are told that good training will insure that pilots work within safe limits,but I believe that is so only for those whose attitudes on the ground and in the airfoster safe and sane operations. Training will do little for those whose attitudes areless than desirable, yet when I read reports revealing the actions of the pilot after anaccident, sometimes I wonder why this person was flying at all.

So it is that human factors play an important part in aviation accidents, and we mustgive them the attention they deserve. "Psycho-babble" they are not. It is up toeach of us to ensure that when we strap into our airplanes we are fit to fly, physicallyas well as emotionally. And beyond that we need to know the limitations of our aircraft aswell as our own operational limits. If we work within them the chances of being involvedin an accident are significantly reduced. If we don’t observe them just the oppositeoccurs, and there may be a landing in our future that we don’t walk away from.

Human FactorsNOTE: AVweb’s safety editor Brian Jacobson has produced a 35-minute audio tape entitled Human Factors in Aviation Accidents in which he further explores the human side of why accidents happen and what can be done to prevent them. The tape discusses in-flight decision making, error chains, personal limits, personality traits (e.g., risk-taking, lack of confidence), physiological factors (e.g., fatigue, stress), and a number of other things that affect a pilot’s decision making abilities, and illustrates these issues by describing and analyzing a number of actual accidents. You can order it on-line for just $14.95.