Tuesday, December 16, 2008

Choosing Your Handheld

What to consider before you purchase a GPS, EFB or NAV/COM

handheldPilots today are increasingly dependent on electronic navigation and communication equipment: GPS for navigation, satellite radio for weather avoidance and VHF for voice communications (since September 11, no pilot can seriously think about flying in controlled airspace without one).
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choosing handheld
PCAvionics’ MountainScope
Tablet PCs and PDAs weren’t designed for use in the cockpit. They’re general-purpose devices intended mainly for use on the ground, and that can compromise their functionality in the air. Most PDAs have transflective displays that work well in any light, but this isn’t true of Tablet PCs. Before buying any such device for aviation use, ask to see what it looks like outside on a bright day. Also ask to see it in very dim light: Many Tablet PC backlights can’t be turned down enough, and can be blinding in a dark cockpit. Most EFB software that run on PDAs and Tablet PCs have a touch-screen interface with on-screen menus and buttons that are accessed using either a stylus or your finger. That works fine on the ground, but can be difficult in rough air (to be fair, dedicated buttons can also be hard to use).

choosing handheld
Digital Cyclone’s Pilot My-Cast


Another catch is that EFBs aren’t as reliable as dedicated aviation GPS navigators. That’s a direct consequence of using a general-purpose platform. The avionics vendors who make GPS navigators completely control what software is used on the device, which creates a predictable environment. That’s not to say they’re perfect, but the odds of having a problem are low, and if you do have one, turning the unit off and then back on will usually fix it in a matter of seconds.

choosing handheld
Hangar B-17’s

Not so with an EFB, where you’re running a general-purpose computer operating system, which hosts your aviation software on a general-purpose computer. The same bugs that bedevil desktop computer users also can impact your EFB, and some vendors of EFB software recommend that you run only their software, with no other applications. That gives a more reliable environment, but defeats the purpose of having an EFB.

choosing handheld
Stenbock & Everson’s ChartCase Professional Software
Once you’ve made the choice between a dedicated GPS navigator or an EFB, the next thing to consider is what features you want. Most devices offer basic moving-map navigation, but that’s only a beginning. Other available features include satellite-radio-based weather (which requires buying a satellite radio receiver and weather subscription) and traffic (which requires a Mode S transponder, ADS-B device or portable traffic sensor). This is where EFBs have an advantage: As a general-purpose device, you can add weather or traffic to just about any EFB by purchasing the necessary hardware and an appropriate software package. If you want these features on a dedicated aviation GPS, you’ll have to pay for them up front; only top-end models support them.

choosing handheld
Midwest Sport Aviation’s FlightMaster
Other features that may be built in (or available) are sophisticated aviation databases including instrument approach procedures. Though you can’t legally use any portable device as your primary navigation source while flying IFR, monitoring the procedures on a moving-map display is perfectly legal for situational awareness on Part 91 flights, and in a pinch, the ability to fly those procedures could save your hide! A few devices can provide a complete backup instrument panel, based on GPS position and/or input from an electronic gyro. In an absolute worst-case scenario (simultaneous electrical and gyro failure while flying IFR), that could save your life.

choosing handheld AirGator's NavPad 5
Two more items bear consideration: mounting and power. While all these devices are called “handheld,” in practice, most pilots mount them on the yoke or glare shield. Most dedicated GPS navigators run on standard batteries, and can also be run from a cigarette lighter, if your airplane has one. That’s a good solution for most pilots: Run off the aircraft electrical system and save the batteries for emergencies. EFBs, by contrast, almost always have rechargeable batteries, and may require special adapters to run off the aircraft electrical system. If you only fly short hops, running off the battery is fine, but Murphy’s Law says the one time you fly an unexpected extra leg will be on a day when you forgot to charge the battery! And now, on to the handhelds:

BENDIX/KING'S AV8OR is a shirt-pocket-sized device with a 4.3-inch touch-screen LCD and integrated GPS. It includes an aviation database with terrain, navaids, obstacles, airspace and airports, and an automotive database that provides street-level maps, turn-by-turn navigation and points of interest. The AV8OR can also display aviation weather data from an XM Satellite Radio receiver (not included). Price: $749. Contact: Bendix/King, (800) 601-3099, www.bendixking.com.