The shock is fatal, not the virus

According to accident investigations, the vrille, or the failure to end the vrille in good time, is responsible for many fatal flying accidents in both powered flight and gliding. Reason enough to do something about it.

Author: Alfred Ultsch

Startle kills people, not the Vrille: When I first heard this sentence, I was extremely skeptical, not to say incredulous. "Startle", or the startle reaction, is not a child's ghost, but the psychological term for a reflex to which we are all sometimes more, sometimes less subject. It is a violent, involuntary reaction to a sudden situation that is perceived as life-threatening, i.e. a reaction to a sudden emergency. A problematic startle reaction for flying is the so-called startle paralysis that occurs.

Startle causes the pilot to be torn away from their current actions. The pilot's attention is focused, completely or at least for the most part, on the startle-inducing effect. In the case of a sudden, unintentionally induced vrille, this is usually the fixation on the earth's surface, towards which we appear to be hurtling vertically. At worst, the involuntary reaction is to jerk the control stick backwards and hold it there convulsively.

The startle paralysis that occasionally occurs during a fright means that the pilot is initially unable to react because, controlled by unconscious processes, he is unable to carry out coordinated actions. Evolutionary biologists assume that both the startle reflex and startle paralysis are genetically built into us. If we play dead immediately, a suddenly appearing predator, i.e. the proverbial lion leaping out of the bushes, may not notice us. A reflex implemented in us therefore has an important protective function. When flying, however, a startle reflex can cost us valuable seconds. When spinning, these are ultimately vital meters of altitude that we need to complete the vrille.

Resistance to fright can be trained

But there is help: both fright resistance and the shortening of action rigidity can be trained, especially for pilots. To do this, it is important to practice the appropriate action (skill) for the situation "mechanically", i.e. as an instinctively retrievable unit of action, and to train it proactively from time to time. In concrete terms, we have to physically repeat the action patterns for deploying the vrille, which are often specific to airplanes, or the action patterns for a sudden rope break during a winch launch, until they have become "second nature". We don't even have to train this in an airplane. We can even simulate this on a chair in the living room. The important thing is that we train the appropriate movements until not only our brain, but especially our body has learned them. There is a well-known checklist for the action sequences during a winch launch: "push, release, think".

Annual training helps

Once you have practiced the vital movements for ending a critical situation, e.g. "lowering the elevator, waiting, opposite rudder, gentle recovery to normal flight attitude", they should be repeated in practice at least once a year. There is an opportunity to do this during the so-called "check flights", which many clubs and flying schools expect every pilot to do at the beginning of the season. If you are planning a safety training flight (STF) instead of a check flight, it is a good idea to agree with your flight instructor that you will practise actively practising your take-off roll in the event of an unexpected vrille.

The most common flight situation according to accident investigations can be used as a training scenario: a completely flat turn.  In such a turn with significantly less than 30 degrees bank angle, the aircraft slows down "imperceptibly" and a stall is also permitted. If ailerons are added in the direction of the turn when the stall speed is reached, this can cause a fatal shock: The airplane tips suddenly and in an unexpected way, namely in the opposite direction to the intended turn, and can - if we allow it through take-off - go into the vrille.

Of course, these maneuvers should be practiced at a sufficient altitude so that even in the event of a startled stall, with a delayed or incorrectly executed recovery maneuver, a rescue from the critical flight attitude with subsequent safe continuation of the flight is possible.

Conclusion: The startle does not have to kill us. Automating the right actions beforehand (mechanization) and using an annual safety training flight to reduce the startle response are our lifesavers.