Flight Training - August 2012 - 33

WAAS UP?
The FAA is so confident in GPS’ ability to accurately provide position information that it now allows pilots to fly approaches in instrument conditions down to fewer than 300 feet above the ground. To make this possible, the agency built out an additional layer of accuracy on top of GPS called WAAS, or the Wide Area Augmentation System. WAAS ground stations monitor the GPS satellite signals, adjust them to be even more accurate, and then send that data back to the satellite, where it is sent again to the GPS receiver. Although the purpose of the system is to allow for more precise navigation for instrument approaches, even many inexpensive handheld units boast WAAS capability.

not foolproof. Displays fail; information can be incorrect or incomplete; and interpretation of the data can be flubbed. For these reasons it’s important to always bring sectional charts, and follow along on the sectional as you would if you didn’t have GPS. With this combination the word “lost” should take a hike from your aviation vocabulary.
SO MANY CHOICES. Because GPS chips are so inexpensive, they are being placed in everything from cell phones to jogging trackers. Combine that with inexpensive touch-screen technology, and a huge range of GPS receiver choices is now available to pilots. These generally split into three categories: panel mounted, handheld, and the iPad. Yes, the iPad is handheld, but if you’ve used one you understand why it’s in its own category. Panel-mounted receivers are the most expensive, but they are also the most reliable and the most diverse in terms of capability. The necessity of a hard-wired antenna and a dedicated power source means panelmounted units are the only ones that the FAA will allow for official navigation. An instrument-rated pilot trying to file /G will need to have an appropriate approved panel-mounted unit. Until recently panel-mounted units were the only ones to have approach and other capabilities anyway. But that’s changing. Today’s handheld units start at around $500, and even at that price point, they provide a full range of flight planning, charts, and weather connectivity options. Although you cannot use a handheld unit for navigating on instrument flights, the information you get will be useful for situational awareness, regardless of the type of flying you do. Each unit functions a bit differently, so it’s best to comparison shop at a place such as Sporty’s, PilotMall, or other store that carries multiple brands. The best way to do it is at a show such as EAA AirVenture or AOPA Summit, where all the units will be on display. Finally, the iPad really is in a class by itself. It’s not a dedicated GPS unit, although it does GPS-like functions quite well. Reliability reports vary, with many pilots complaining about overheating, apps locking up, and so on. It’s prudent to make sure you have backups. If you are going to buy an iPad for flying, there are a few things to consider. The non-3G version doesn’t have the GPS hardware you’ll need for aviation, so a supplemental GPS will be required. These cost about $100. If you use the 3G version don’t expect accuracy like that of a dedicated GPS unit, although one meter isn’t much different than 10 meters when you’re flying VFR. Then you have to decide which app to use, as there are many choices. There is no “best” app, only the best one for you. Just as you would try out multiple handhelds before purchasing, you can try many of the apps as well. Once you settle on an app, a handheld GPS, or rent an airplane with a panel-mounted unit, it’s time to be a good boy or girl and follow the magenta course line. Resistance is futile.
Ian J. Twombly is editor of Flight Training magazine.

BESIDES FLIGHT PLANNING, GPS'S BIGGEST BENEFIT IS LIKELY THE ADDITION OF MOVING MAP DISPLAYS AND THE STAGGERING AMOUNT OF SITUATIONAL AWARENESS THEREBY ASSOCIATED.

AUGUST 2012 FLIGHT TRAINING

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Flight Training - August 2012

Table of Contents for the Digital Edition of Flight Training - August 2012