Tuesday, September 23, 2008

How much can you fit in your head?

When I got into this, I figured it was going to be tough. I was right. What I didn't realize was how much other stuff you have to learn when you're learning to fly helicopters -- or more specifically, how much other stuff you have to learn to get your helicopter pilot's license.

Here are some of the major areas of knowledge (although I'm leaving some out, I'm sure). Each of these is a vast subject unto itself:

Aerodynamics of helicopters
Where do I start? You have to learn the physics of lift, weight, thrust, and drag. (The latter would include profile drag, form drag, induced drag, and parasitic drag.) You have to understand the physics of airfoils. The consequences of rotor blades changing angle and/or speed. Newton's laws. The Coriolis effect. Bernoulli's principle. Gyroscopic precession.

But wait, there's more. You must understand the incredibly complex interdependent relationships between the controls, the main rotor, the tail rotor, the engine, and the aircraft body, all of which are subject to changes in the others, but in very complex ways. Remember when I said that helicopter pilots couldn't possibly understand all the technical information in Principles of Helicopter Flight? I was wrong. They do.

Physics of air
Helicopters are incredibly sensitive to changes in the density, temperature, pressure, and moisture content of the air in which they are flying. It's very possible, if you aren't careful, to take off at one airport, travel to another where the air is different, and not be able to hover or land. So not only do you have to understand the physics of these air qualities, but also how to predict how they will affect the helicopter, from minute to minute and place to place.

Obviously, if you have to know the physics of air, you also have to know what the air is doing where you are, and where you are going to be. So you have to understand weather theory, weather patterns, forecasting, cloud types, precipitation, fronts, storms. You also have to know how to find and obtain the relevant weather reports for your flight, and then decode them -- because all weather information is published online in a highly abbreviated form that looks like gibberish.

Aircraft systems
You have to understand how your helicopter works. Not just put the gas in this hole, like with your car. You have to understand spark plugs, carburetors, transmissions, alternators, oil systems, fuel systems, electrical systems, and so on. You have to know where these things are, so you can check them before a flight, and you have to know what the consequences are if one of them stops working correctly. So you can recognize the problem and address it. While flying.

There are several essential instruments: Altimeter, airspeed indicator, vertical speed indicator, manifold pressure gauge, and compass. (Am I forgetting one?) You must not only understand what they are and what they are telling you, but also how their insides work and under what conditions they might give you bad information. Here's an actual question from the FAA pilot's test:

In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the north when:
a) the aircraft is decelerated while on an east or west heading
b) a left turn is entered from a west heading
c) the aircraft is accelerated while on an east or west heading

The answer is C.

While GPS makes it much easier for aircraft to find their position, you still have to learn all the old methods used with compass, pencil, plotter, and navigation beacons, of which there are several kinds, all different.

Oh, and have you ever seen an aviation chart? It's a kaleidoscope of colors, lines, and symbols, all of which mean something, and if you're flying near any of them, you better know what they mean. Here's a picture of the San Diego area:

Rules and regulations
You know how every so often there's a Popular Science article about how we're all going to have flying cars in fifteen years? My helicopter instructor and I had a real good laugh over that. People have enough trouble staying between the yellow lines and stopping at red lights. The rules and regulations you need to know and follow to be a pilot are far more complex. Believe it or not, there is a lot of traffic up there, and lots of rules to follow.

Airport operations
Obviously, airports have serious potential for accidents, not just because aircraft are taking off and landing there, but because there are so many aircraft in a small area. Not to mention fuel trucks. So you have to understand all the procedures, signs, and lights that are used at airports. And you have to be able to look up any airport in the country to get all its particular idiosyncrasies before you go there. Remember how I said all weather information is in highly abbreviated, cryptic code? Yeah, same thing with airport info.

Radios and communications
Pilots and air traffic controllers speak a different language. First, you have to learn the language. Then you have to learn when you're supposed to talk, and when you're not. And what you're supposed to say. To whom. But that's just part of it.

You also have to know how to operate your transceivers, which are the radios you talk with, and the transponder, which broadcasts your aircraft's position and altitude. You have to know what frequency you should be talking on, depending on who and where you are. And what transponder setting you should use.

You have to know what to do if your transceiver stops working and you can't talk. And how to communicate if you've been hijacked. You should probably also know the transponder setting used by the military to identify unmanned targets. Might want to avoid accidentally advertising yourself as one of those.


So those are the basics. To think I could learn it all in six weeks was nuts. What does that mean for me now that I'm back from Hawaii and back at my day job?...well, I guess that'll have to be the subject of another blog post.

1 comment:

Justin said...

Maybe you forgot the engine and rotor tachometer...?