Posts Tagged ‘GPS’

GIGO

Monday, August 10th, 2015

It’s early on in your academic training these days when a teacher refers to the GIGO principle. Simply stated, if you are using a computer, it doesn’t matter how great the machine or the program is if you input bad data. If you put in garbage, it will give you garbage results. Garbage in, garbage out: GIGO.

In flying this is a very real concern, particularly when it comes to programming a GPS. It’s one thing if you inadvertently put in a wrong fix that’s close to the right one, but that’s rare. What’s more likely to happen is that you put in the wrong fix or the wrong piece of performance information, only to suddenly find yourself asking what is going on. When the airplane makes a turn you aren’t expecting, you’ll be scrambling to figure out where the mistake is. It’s great if it happens on the next fix. That usually becomes readily apparent. It’s not so great if you programmed in the wrong fix several legs down the road.

This is an easy mistake to make on a GPS that is programmed with a knob, and it’s an easy mistake to make in a crew environment. I’ll give you an example: I was in a simulator event, and I had the airplane doing exactly what I wanted it to do. Trying to stay ahead of things, I decided to program the climb performance, not registering that the performance I was asking for was for the cruise climb. Asking the airplane to change its profile would cause all kinds of problems on the departure procedure. Following our prescribed procedure, I asked the captain to verify what I was getting ready to do. He did. I hit the button and executed the new plan. To my horror, the airplane began to accelerate and climb like it had a date with Mars.

I quickly turned off the autopilot and autothrottles, and I asked the captain to reprogram “the box” while I hand-flew and kept us out of further trouble. In my peripheral vision, I saw the instructor smile and write furiously. In the debrief, we got kudos for catching the problem immediately and fixing it, but we also got a reminder that GIGO can happen at any time, at any place. It was a great lesson, and it happened in the sim, where nobody could get hurt.

I’ve flown now for more than 20 years, and I have a litany of such GIGO examples—some mundane, some not so much. What I can say is that I don’t tend to make the same mistake twice, but I’ve learned that I am never going to be immune to this kind of error, which is good, as it keeps me on my toes.

But if you want to see how catastrophic GIGO can be, just look at the report for American Airlines Flight 965, which crashed into a mountain in Colombia in 1995 because of a flight management system programming error. It’s a stark reminder of how quickly things can go wrong, even for an experienced crew.—Chip Wright

Which comes first: flying or ground school?

Wednesday, January 9th, 2013

It’s a classic aviation topic of discussion: Do you start with ground school or flying lessons?

The answer, of course, is yes.

Back in the day, pilots-to-be overwhelmingly sat in a classroom and learned the academic side of flying the same way they learned algebra, English, and history. Courses would run several weeks depending on how many days a week it met, and most students were flying concurrently. Nowadays, so many pilots engage in the self-paced home-study courses that it’s probably difficult to find a traditional ground school.

The advantage of starting with flying right away is that you have a much easier time keeping up your enthusiasm, and besides, flying is fun, so why not do it? The truth is that you can do both at the same time, but you need to learn how to do it efficiently and effectively.

The home-study courses available today are a far cry from what was available even 10 years ago, and they are light years ahead of where they were 20 years ago. Jeppesen used to charge a king’s ransom for a series of video tapes that accompanied the private pilot curriculum. Now, online classes and DVDs have replaced VHS, which means you can go right where you want to study, and better yet, it’s all interactive, which keeps you more engaged. The video quality is better as well. And Jepp being Jepp, they still charge a king’s ransom, but the Kings are still doing their thing as well.

There are some areas of study you should start with right away. Aerodynamics, the FARs, and weather are topics that you can’t get a jump on fast enough. Most people are more weather savvy today, thanks to the Weather Channel and the Internet, but aviation weather is still information intensive, so getting a leg up on it early is always a good idea.

But a few areas of study call for caution when it comes to getting too far ahead of where your training is. You should spend a lot of time reading, watching, and studying all of the maneuvers. However, don’t jump into trying to understand all of navigation until you are ready to do your cross-country flying. In more modern aircraft, you may already have a bit of proficiency with the GPS since you use it all the time. In older airplanes, it may just be you and your VOR indicators. I am a firm believer that you will be a better pilot—you’ll certainly be more knowledgeable—if you can do everything the old-fashioned way, and that includes using a manual E6B. After all, it doesn’t ever need to have batteries replaced. As for the panel-mount GPS, a good instructor will take the time to show you all the ins and outs you need to know as you need to know them.

When getting ready for your knowledge test, don’t do it by just memorizing all of the answers. Make sure that you understand the theory and the concepts discussed in each question. Be able to answer them using what you know, especially weight and balance and navigation questions. Some of them are indeed rote memorization (the FARs), but make sure you really know the material and know where to find it!

Learning all that you need to know can seem daunting, but if you break it down into chunks, it is much more manageable. Yes, you can fly before you open a book, but if you combine the two, you will have more effective learning and have a more enjoyable training experience.—By Chip Wright

The best instrument there is

Wednesday, March 21st, 2012

When I first started flying, I used to hear a lot of old timers tell stories about navigating with NDBs and the four-course range. VORs were the sexy new toy of the future. I still didn’t understand how one could safely navigate across the ocean, since VORs didn’t exist on water. I knew that the concept of taking star sightings existed, but I also knew that it was premised on a clear night. Conceptually, I think I knew that the speed of jets would make such triangulation difficult, but not impossible. It also didn’t dawn on me that not every nation in the world could just lay out VORs willy-nilly the way the United States did.

I also heard a lot of stories about the development of the flight instruments. Early versions of attitude indicators and directional gyros were primitive by the standards I was used to. The radios themselves were not always very good. It seemed like there were two classes: top-of-the-line Bendix-King…and everybody else. The Cessna radios were pretty good, but they didn’t have any of the “cool” features like flip-flop windows, DME, and the like. DME, by the way, was some kind of cool. Garmin rules the radio world now, it seems.

It wasn’t long before I began to follow in earnest the homebuilt movement. Kitplanes were just beginning to spread in great numbers—early RVs, Glasair, Lancair, and Kitfox dominated the advertising—and they also spawned a great deal of innovation that we now take for granted. A lot of the modern avionics that cost truckloads of money got started in the experimental arena. Certification wasn’t nearly as stringent, and the rapidly improving computer technologies (both hardware and software) invited a great deal of experimentation. A lot of the inspiration was drawn from airline and military “stuff,” but much of it was simply new. The cost was much lower than it would have been had everything been put through the gamut of FAA testing. It was clear that the homebuilders were leading the way. Nowadays, new airplanes with “glass” technology are taken for granted.

GPS, of course, has changed everything. I personally miss the days when pilots learned the intricacies of aerial navigation not just to pass a written test, but because their lives depended on it. But GPS simply makes a mockery of pencil-and-paper travel. With GPS, you don’t need to call Flight Watch for winds aloft; the heading for the nearest airport is a button push away; and the moving map makes a paper sectional seem quaint…but I still like the paper chart.

NDBs are relatively rare, and the GPS overlay approach can provide lower minimums. Other things long on a pilot’s wish list were an RMI, an autopilot, loran, weather radar, and better “orange juice cans” for the Cessna series. Today, such items have either been leap-frogged or accomplished.

But the most important instrument in the plane doesn’t get much attention. It isn’t fancy or sexy or sold by women in bikinis. It is, however, the cheapest in terms of bang for the buck, and it doesn’t let you down.

As fast as computers are, and as nifty as Nexrad weather is; as efficient and reliable as a moving map is; as handy and helpful as a TCAS display is; the fact is that nothing on an aircraft—or even a spacecraft—can hold a candle to the value and utility of…the windows.—By Chip Wright