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Monday, 28 October 2013

Theory, theory, theory

I have started my PPL (Private Pilot's License) theory course by now. That consists of 7 subjects, each with their own exam. I get 18 months to pass all exams, starting from the first try. They are multiple-choice questions, of which at least 75% of the answers need to be correct, to pass the test. During the 18 months, one gets 8 tries, and in those 8 tries, one has to pass all 7 subjects. The strategy will be to do multiple exams per try, but not too many, because then you'll be too worn down for the last test. Plus, you'd need to study all the subjects at once, and chances are, that you'll have forgotten too much of the first subject you started to study, already.
Furthermore, one has to follow classes with a state-accredited (flight) school, so doing it all as self-study is not allowed. Not that I had intended to do it all by  myself! I know quite a lot already through my Flight Simming experience. But all that, I got from well-meaning amateurs like myself. So it is very well possible that I have taught myself wrong things. And for sure I did not teach myself everything. KLM Aeroclub does not have enough appliccants to maintain a certified instructor for theory classes, and to keep the theory education certificate valid every year. So I registered with another certified flight school: "Dwarf Powered Gliders", based atHilversum Airport (EHHV), after consulting with my Flight Instructor, and some flying friends.

Dwarf Powered Gliders, off to the right of "Vliegschool Hilversum"
We are with 8 in our class. Large enough so it is still economically viable, yet small enough for personal attention during class. Ideal! In principle, I have class every Thursday evening, and during the weekend before an exam date, a Saturday morning of exam training. All this until June 2014, so I won't be bored for another half year :)
First two subjects are "Aircraft General Knowledge, and Principles of Flight" (AGK/PoF), and Performance and Planning (PP)
AGK is all about the airplane itself: What are all the parts called, what do they do, why are they there... Most of it, I already knew, but I must admit I was surprised of how much I learned new as well. For example instruments: I knew that an altimeter was just a mere (static) pressure gauge, but how that works on the inside of that box, was new to me. Same for the Air Speed Indicator; I knew it subtracts static pressure from total pressure (resulting in dynamic pressure), but how that is mechanically done ...
PoF is, in fact, Aerodynamics. It used to be a separate exam, but was fused with AGK to a single one.. When I was still in college (BSc echanical Engineering), I lived a while with three students Aeronautical Engineering. I always said that that was the same study, but with a different medium (air in stead of water). Dat is still the case ;) Keeping an airplane in the air is simply harnessing the kinetic energy of the air (1/2*m*v^2, per m^3 1/2*rho*v^2) to generate lift. In order to accomplish that, one uses wings with a certain profile, and relative angle to the flowing air: Cl. This profile has an effective surface area A, and voila: the Lift formula: 1/2*rho*v^2*Cl*A. The energy conservation law and continuity law complete the set of tools one needs to master for this course. "F=M*a, and the rest can be derived", to quote another (in)famous sentence from my college years.
Once in the air, it's always nice to know just about how long you can keep that up, and how far you'd get in that time. PP is all about that kind of calculations: range, fuel consumption, speeds, times, mass sistribution, ... In short: a calculus subject. In order to not have to do all those calculations by heart, and not be dependent on batteries, someone invented a special slide rule (a circular one at that), that is called an E6B Flight Computer. It has, amongst others, a time scale, so that time related calculations become a lot easier. No need to divide by 60 all the time, to multiply the remaining fraction by 60 again. Pffff.
E6B Flight Computer
These are my kind of subject, as a technically inclined person. I don't expect too much problems, as long as I keep my cool, and take the time to read. In fact, that is the thing I fear most in these subjects: questions with all the same answers, formulated slightly differently, for which you need to pick the best answer (as opposed to the one good answer). There's always a couple of those questions in the exam, and there is not a lot of margin in the number of errors allowed.

My exams for these subjects are planned at November 12th. Suspense ...

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