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Friday, 26 October 2012 14:45

Zero error margin

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When you ask a stunt pilot in an airshow how the risk can be controlled, the maxim usually used is “make what is easy look difficult, and what is difficult…don’t do it.” However, the reality of airshows reveals to us that if in aviation there is no such thing as zero risk, this is even truer in the world of aerobatic exhibitions.

We say that flying is safe, and it is, but it’s because when a pilot gets on a plane it’s because he knows he is taking a risk. The aircraft has to be in flight condition; and the pilot also, whether physically or mentally, and of course, with adequate preparation for the work he has to accomplish. In air shows he doesn’t go up one rung on the ladder of risk, rather several suddenly. The “speed and height retain the denture” that they teach us when we begin to fly is conspicuous because of its absence at an airshow in which the demonstrating pilot wants to fly as close as possible to the audience and in which the logo of his sponsor can be seen clearly.

But the pilot already knows these factors before facing an airshow. They are the determining factors that should make him twice as alert as in a normal flight, forcing him to train a little more and keep a cool head so that safety is the first and only factor that determines his actions. So then, what is the real risk at an airshow? The pilot.

Thanks to the European and United States community of airshows that meets annually at the conventions of the European Airshow Council (EAC) and the International Council of Airshows (ICAS), you can learn of the errors and accidents that exhibition pilots suffer throughout the world, many times with fatal results. I especially want to make mention of General Des Barker of the South African Air Force and his excellent book “Zero Error Margin,” the bible on flying safety at airshows. Every year, General Des Barker produces an exhaustive analysis of airshow accidents throughout the world, studying the causes and extracting valuable lessons for pilots and organizers. 

 The chief lesson? ‘There are no new errors. Only new pilots committing old errors.”

Airshow accidents could be an appendix to the textbook for the PPL and ATPL human factors course, now that in the world of aviation the decisions of the pilot are responsible for 90% of the disasters, and this figure rises to almost 100% at airshows.

The motives vary, but primarily they fall into two major categories: the pilot’s desire to please the public and his sponsors, and the lack of recognition or error in calculating the limitations of the aircraft or of the pilot. In both cases, the missing link in the chain of safety is the mental discipline of the pilot: the self-imposed rules that, for one motive or another, we end up betraying, which unfortunately, often results in fatal accidents.

The first scenario may seem reserved for the “Sunday pilots,” those who don’t usually do exhibitions, and when they are given the opportunity to fly before tens of thousands of people, let go of their good judgment and go beyond their training and capabilities. However, this description can apply to the more experienced pilots. Representatives of the sponsoring organization being present, or a mandate from the army in the case of military patrol, performing in the birth city of the pilot, and so on are motives that can drive a pilot to “give a little more” and break the safety regulations. Or to simply not interrupt a routine despite knowing that he has made errors or lost too much altitude.

How to you avoid this? A good airshow director is capable of detecting if a pilot is “heating up,” or if his flight isn’t clean, having the authority to interrupt the program. If the director says, “Knock it off,” it is a warning letting the pilot know that his conduct is not acceptable and if he doesn’t correct it, inevitably he will end up hearing the feared “Stop, stop, stop,” - and on towards home.

In the same way, the demonstrator military teams communicate with a safety coordinator on the ground who monitors the whole exhibition with a radio station and is familiar with the routine, down to the details. If he sees something he doesn’t like, he has the authority to interrupt the program.

But the most important thing is that the pilot pursue the maxim imported from military aviation: “Train like you fly. Fly like you train.” The airshow exhibition is one more flight, and our mental state has to be the same as when we train, prioritizing safety above every other consideration.

One sad example is of the wingwalker Todd Green, who fell to his death while performing his flight routine of passing from a Boeing Stearman to a helicopter. Should he have done it on such a windy and turbulent day? Is it worth it to risk one’s life in order to fulfill a contract with an airshow festival?

The second scenario normally occurs at aerobatic shows with historic aircraft or pilots who are not professionally dedicated to the world of airshows, although it can affect anyone. The fact that we have made a maneuver with a plane that doesn’t forgive errors and whose velocity vector increases at an alarmingly high rate when the nose points to the ground does not mean we dominate it in all situations. What is the air density? And what if the engine doesn’t give 100% power during the rise of a 45 degree inversion of low altitude?

The clearest examples is of the F-16 of the USAF Thunderbirds on Mountain Home Air Force Base, Idaho: the pilot incorrectly noted the altitude of the field above sea level. Because of this, he also miscalculated the altitude at which he should begin the 45 degree half barrel roll after takeoff. From there, the accident was inevitable.

You have to remember that we should always have in place some wide safety margins and not EVER transgress them. The human brain is designed to think at a velocity equivalent to walking or running, but not to making decisions riding in four metric tons of steel moving at 300 Km/h. We always lag behind the plane. The only solution that the brain has for being able to pilot a plane is to automate the majority of the processes. The training of the pilot is based in a repetition of concepts that ultimately becomes a part of us, that which we do without thinking. And it is precisely here where the danger resides.

How many times have we driven from one place to another and by the time we have realized it, we had already arrived without knowing how? Automation allows us to be able to complete various complex tasks at the same time, without thinking. What happens when we have to make a decision in a fraction of a second, when the workload in the cockpit and the stress have our heads in the clouds? The brain has to automate, to do what it has learned. And that can cost us our lives.

If we have always done the same maneuver, we will have to complete it in the same manner. If we don’t have sufficient altitude when we have started it, really we will have to take control consciously of the situation and INTERRUPT immediately to re-evaluate the situation.

As an example, the problem is this slow barrel roll after the takeoff of an F-18 in Abbotsford. The pilot detects a problem and corrects the situation, scarcely avoiding having to eject himself.

As a counter-example, the fatal accident of Bryan Jensen in Kansas City: Did he have sufficient altitude to begin the gyroscopic maneuver? Should he have cut off the rotation before? By the time he realizes, he doesn’t have altitude and upon trying to forcefully recover, the plane spins out leaving him with without options.

 I don’t want to go on any longer; as an introduction to the world of flying safety at airshows, this text already fulfills this purpose. I highly recommend the book “Zero Error Margin,” that you can find here:


And remember:

“As pilots, only two bad things can happen to us: that one day, after many, many years, you walk into your plane knowing that is the last flight that you will make in it. Or that on any given day you walk into your plane without knowing that it is your last flight.”

It depends on us.

Daniel Ventura González Alonso


Read 7547 times Last modified on Friday, 17 January 2014 14:48
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