Sunday, February 6, 2011

Ground School

This semester I am taking a not-for-credit class that I am really excited about - Private Pilot Ground School. I have always wanted to get a pilot's license (it's on my wish list), and it turns out that the Flying Club here at World's Best School teaches a class every semester that helps you get your license.

To get a private pilot's license, you have to take a written exam, an oral exam, and then the actual flight exam. The Ground School class is intended to teach you all the knowledge necessary for the written exam. Some things about flying a plane you can't learn until you actually, you know, FLY the plane, but there's a lot you can learn on the ground. Thus, Ground School.

As a side note - if I get a pilot's license, I can add it to my driver's license and my scuba diving license, and now I'm all set for land, air and sea! Just call me Double - O....

The first class was this past Wednesday. Now when I was in undergrad, I did an Aerospace option for my senior year, so I have taken a couple Aero classes. I figured given that experience, I'd probably be familiar with at least some of the material. I skimmed the slides for the first ground school class ahead of time (overachiever bug is still alive and well after all these years in school), and I thought - well I have this in the bag.

So I walked into class the first day quite full of myself - didn't even bring paper and pencil to take notes. I leaned back in my chair, looking around at all the incredibly young faces in class, feeling smugly superior in my grad student status.

And for the first part of class, I did indeed have it under control. "This is an airplane," said the instructor, gesturing to an inflatable model, "This is the wing, and this is the engine." Easy, easy. We continued on. "This is an aileron, on the wing, and the elevator on the horizontal stabilizer, and the rudder on the vertical stabilizer. These are your control surfaces." the instructor explained as she pointed to each piece.

Still good! I have actually physically built all those parts. I helped build small remote-controlled airplanes in undergrad, so I am quite familiar with all the various flaps and structural pieces. And my speciality is control systems, so I even have a good idea how those control surfaces affect the plane.

We continued on, going over things like "Don't Drink and Fly" (the rule is eight hours bottle to throttle), and the different kinds of licenses you can get (multi-engine, commercial, instrument, etc.). As the instructor flipped through the slides, I glanced at the clock - the class goes 6 to 8pm, and it was about 7pm. I hadn't had dinner yet, and my stomach was starting to let me know.

The instructor also glanced up at the clock, realized both that it was halfway through class, and that she was not halfway through her material. "Okay class," she said, "We're going to have to speed up."

So we started flying (ha!) through the slides, at the same point the material was becoming new to me. Is the plane stable in roll? Stable in yaw? Stable in pitch? If the answer is yes, is it positively stable, neutrally stable, statically stable or dynamically stable? Or all of the above? None?

Ack! By the time we got through that section I was convinced that while a plane, in flight, COULD theoretically be stable, in my hands it would quite probably go UNstable quickly and dramatically. In fact we watched several painful YouTube videos to underscore how terribly, terribly things can go wrong in a plane. (How helpful, thank you!)

And then.


"Now," chirped the instructor, "we will talk about turning the plane."

 This is where my brain exploded.

To turn the plane to the left, for instance, you roll the plane left. The instructor drew a nice diagram on the board of the wings, tipped to the left. Now when you roll left, you create more lift on one wing than the other. The different lifts cause different drags, so you end up yawing to the left as well.

More pretty arrows were added to the diagram.

In addition when you roll left, the net force vector is now pointed at an angle, and your total force is now split into a vertical and horizontal component. That means you have less total lift going up, so your nose points down, and you have to compensate by pitching up.

Now we're in three dimensions, and the instructor had run out of ways to draw arrows, so she gestures with chalkboard erasers.

I have decided that if by some miracle I can prevent my plane from going unstable, I am never going to be able to turn. I will just have to pick an airport that is directly lined up with my final destination. Six degrees of freedom? Are you Aero people nuts? Thank goodness my MechE career only deals with a few degrees of freedom at a time....

Reeling from thinking about forces in three dimensions, I glanced again at the clock. 7:30pm. My stomach was talking to me now, and it wasn't a happy conversation.

"And now," said the teacher, "we are going to learn the really important information."

Really? Now?

"Now, listen closely, because here's the proceedure for getting out of a spin..."

Oh, no. This I may have to pay attention to. I stared as she drew on the board, spelling out acronyms for "easy memorization." Where was that paper and pencil I was too arrogant to bring??

"Okay. Now in addition to a spin, you may also get into a stall. So here's how you get out of that."

More acronyms. "And CAREFUL! This particular procedure is not instinctive, and in fact your instinct will be to do the exact OPPOSITE." Oh gees....

"And finally, class, we need to go over what to do in case your engine stops."

Okay, now, enough is enough! I'm going to need dinner for this... :)

I did try to pay attention to the engine-out case, but man I was starving, and my poor brain was fried from trying to think in six degrees of freedom. I left class no longer as smug as I was going in.

And now with the benefit of a few days to ponder the material, I waffle between thinking flying a plane isn't all that hard and that it is designed to inherently positively stable, and thinking that there is an infinte number of ways to screw things up and spiral into the ground. Still, I am very excited about the class and about eventually getting my license. If anything, I have learned that I need dinner ahead of time! Give me a sandwich, I'll read up over the weekend on the spin, stall, and engine-out scenarios, and then bring on next week!

1 comment:

  1. Now you've given me something to look forward to. I'm looking at ground school sometime in the near future as well. Seems like one of those skills a lot of engineers should have.