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What the ***!?

The Startle Response

by Gene Benson

Sometimes being startled can be fun. Sometimes people pay good money to be startled such as watching a horror movie or visiting a haunted house at Halloween. Other times, such as when flying, being startled is no fun at all. The sudden loss of engine power soon after takeoff, an unexpected serious bounce on landing, the sudden appearance of another aircraft posing an imminent risk of collision, the electronic display suddenly goes dark, are just a few possibilities.


Understanding the startle effect and our response to it might help us to be safer pilots. The startle effect originates in the brain stem and has some very interesting physiology, but we will not go into that. Our mission here is to understand just a little about the startle effect and how we can improve the likelihood of making an appropriate response to a startling event while flying.


The startle effect is initiated when our situational awareness is disrupted. That is, when we perceive something that does not fit with our understanding. We are familiar with a particular operation and we have an expectancy of what will happen. If someone believes they are alone in a room, sitting comfortably reading “Vectors for Safety” and there is a sensation of a hand being placed on their shoulder, the startle effect will be initiated. The initial response to that startle event will be involuntary and defensive. The precise actions will vary by individual but will usually involve movement of the jaw, head, and shoulders. Some adrenalin will be secreted which will increase our cognitive and physical abilities. In less common cases, the startle will cause the individual to freeze in place, temporarily unable to take further action.


The involuntary response will be followed by an attempt to regain situational awareness. In our example of the hand being placed on the shoulder, an attempt will be made to determine friend or foe. A familiar voice of a family member will provide renewed and corrected situational awareness and the startle effect will subside quickly. If the hand on the shoulder is followed by a pistol placed against the neck, a new situational awareness must be developed, and the ensuing response will be determined by past experiences such as training. If training in how to handle this situation is lacking, the individual will do the first thing that comes to mind which may or may not be appropriate.


Taking our discussion to general aviation flying, the startle effect can be initiated by the things listed in the paragraph above but of course can include many more items. We have no control over our involuntary response but how we determine the importance of the event and how we proceed can be critical.


I once learned to never trust the student to secure the fuel caps properly after visually checking the fuel quantity. Shortly after takeoff on a night training flight in a Cessna 172, a very loud, continuous banging sound was heard coming from above. I think we can agree that all strange sounds are scarier if they happen during night flights. After the involuntary startle response subsided, the mandate to fly the airplane no matter what else is going on took over. My student was still on the controls but looked at me for guidance. He was doing fine so I keyed the mic and told tower that we would be returning for a landing.


This was a very minor problem. The only damage was to the paint on the top of the wing. But what if the startle response had led to an incorrect action such as an attempt to make an immediate, steep, 180 to return to the runway? Any number of inappropriate actions at this low airspeed and low altitude at night could have been disastrous.


After the involuntary startle response, we must regain situational awareness quickly and decide what, if anything, needs to be done. The more experiences we have available to draw from, the better our chance of deciding on an appropriate action. We can obtain many experiences by flying for thousands of hours. Or, we can speed up the process by taking advantage of quality instruction in a simulator. Begin by training for the most common possible events but also include some rare events. In the actual airplane or in a simulator with high fidelity, make sure stick and rudder skills are kept sharp. Knowing what to do is not much good if we cannot accomplish it. Work to acquire technical knowledge of the airplane systems, how they work, and potential problems. Use a written, or at least mental, checklist for critical phases of flight. For example, a before takeoff checklist would include what action to take if engine power is lost shortly after liftoff.


The startle response comes seconds before the need for urgent decision making that I have written about previously. That subject does not always begin with a startle. Though the strategies to become better at making the correct decision are nearly identical, the involuntary startle response may delay or interfere with regaining situational awareness or recognizing the best action.


The “Urgent Decision Making” course is still available for free by clicking here.