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Sunday, 9 March 2014

Human Performance and Limitations

Every aviation incident has Human Factors as at least one of their root causes. So a lot of research has been put in that subject over the last few decades. Human Performance on the one side, but espacially the limitations. Man was not meant to fly, so we are taking man out of their natural environment, yet still expect them to perform above and beyond what is expected "on the ground". One of those limitations is the amount of information that can be processed. It has been demonstrated that the human brain, when overloaded with information, goes into "survival mode", where only the information that is perceived as essential for survival is processed, and the remainder is "parked" in short term memory, only to be collected again after the essential information pool is processed. Short Term memory has a limited shelf life, so it is well possible that information that is not perceived as essential, is not processed at all.
Now this is all well and understandable, but how does that affect me, the (student) pilot? Surely this will be applicable in a crisis situation, but even then ... I know what to do when things go wrong, so it won't happen to me, right?. Well, I can tell you this: you're WRONG!!!

My third lesson this year finally seemed to go through. It all depended only on how the winds would develop, because the forecast was not very positive (19020G26). About 45 degrees relative to the runway, 20 knots get you close to the demonstrated crosswind component for this airplane (15 knots). Also the gusts were nearing the club limits for flying (30 kts). Challenging weather, especially for an inexperienced student like myself.
When I woke up that morning, I had a cramped out neck, and a terrible headache. I had just finished a couple of weeks of stressful work, and a whole bunch of things besides work. I had my theory lessons resulting in two exams the Friday before, and I have volunteered to help set up a safety management system for the flying club. So all in all I had slept too little in the weeks before, and also had I slept badly, with recurring dreams, and waking up in the middle of the night, that ere associated to that. All in all I was over-tired, and felt like a rag. But that day I would finally get a chance to fly again, and it had been too lang already, in my view. So I took a long hot shower, and that made me feel better already. I had not taken any medication, so I found that I was fit to fly. During the drive to Lelystad, I looked around a lot, turning my head. So by the time I got to the airport, my neck was getting more and more loose already. Wind had not picked up, so we were gonna fly! :)
I got to do it all myself, this day. Taxi, fuel up, take off, climb, level off at 1300 ft, find the "Ketelbrug" (a bridge to the North of Lelystad, where we went to do our excersises last time), and there we did all the excersises of alst time once more: level flight, climbing, descending, level turns, slow flight, slow flight with level turns. This time, we'd also do slow flight with climbing and descending turns. Already during the level turns, I noticed that I wasn't very "sharp" today. When Piet told me to "turn left heading 210", I would realise that I had overshot the 210 heading only at heading 160, or so... Much too late! Nothing safety critical, at this time, of course, but a sign of me being overloaded already...
Once back in the circuit around the airfield, the workload really comes into play. There's just so much thrown at you at the same time, that you need to have an organised flow, or you'll find yourself playing "catch-up" all the way to the landing. Complicating factor this time was the wind, of course. At 45 degrees to the runway direction, it affects you sideways at all four legs of the legs of the circuit. There's a couple of "resting" moments in the circuit, so that's when you can catch up, but you in fact need to be thinking and preparing two steps ahead already.
Because it it now the time in my course to start practicing landings, we would go do a few. Three "touch-and-goes", and one "full stop". By the time we were at the third touch-and-go, I had already lost track of my number of landings, and figured it would be the last one. I did not regiter Piet making the radio call "Papa Lima Quebec, final 23 for touch-and-go", and just put the flaps up after landing, and rolled out, preparing to exit via C. In the movie below of that landing, you can see Piet gesturing that I need to open up the throttle, and take off again ...

Lesson 5, 3rd landing video

KML file lesson 5

I learned a lot, that day. Not only that crosswind circuit work can be a handful, but also, and especially, that fatigue is something that is not to be underestimated. Especially at those moments where your actions become critical, it is absolutely paramount that you have a clear head!
This was all of temporary nature, luckily. A week-and-a-half later, I had a perfect flight with a repetition of all those  exercises, including 4 landings. All went perfect this time. Or at least as good as can be expected of a student with my number of hours, that is ;)

KML file lesson 6

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