With the triple- and sometimes quadruple-redundant electrical systems in the most modern business jets, carrying a backup battery-powered handheld radio or GPS on board might seem as unnecessary as strapping on a parachute or affecting helmet, scarf and goggles. But for turboprop crews or operators of older business jets, the idea of needing such emergency backup might not be as farfetched. And then there’s always the convenience factor of being able to contact clearance delivery, call for fuel or buzz the front desk at the FBO without powering up the aircraft panel; or using a portable GPS with street-map capability for tracking down a restaurant, hotel or finding the way back to the airport.

What’s the likelihood of needing backup in the event of an aerial version of the great Northeast power failure of 2003? Pretty slim. FAA avionics certification regimes include hours of testing under unrealistically torturous conditions. Mean time between failure (mtbf) specifications for communication and navigation components are required to include huge margins. And unlike decades past, avionics suites are designed for and certified alongside the airframe’s electrical system, further improving the odds against the lights going out all at once.

Still, there are those who find comfort in an independent source of communication and navigation sometimes for unexpected reasons. AT&T operates a Citation 560 based in Anchorage, Alaska, solely for use within the state. The airplane provides transportation for technical support and customer service. AT&T chief pilot Michael Burns, based in relatively benign Morristown, N.J. (MMU), said, “In Alaska, they carry both a handheld GPS and a portable navcom, for obvious reasons.” AT&T’s “lower 48” flight operation at MMU does not. “It depends on where you’re flying as much as what you’re flying,” Burns said.

He does, however, carry both types of handheld when flying his personal Piper Arrow, despite having recently installed the latest and greatest panel-mounted big-screen avionics. (He said, “My only regret is that we didn’t do it sooner. Before long, we’ll have weather and terrain mapping, too–almost as much capability as we have in the GIV.”)

Move down a notch or two from the GIV set and you might find a few more Garmins and Icoms in the flight bags, though it appears pride could dictate that some of those backups stay under wraps. Pat Cannon heads up the pilots review of proficiency (PROP) program for Turbine Air Services under a contract with Mitsubishi Heavy Industries (MHI). The PROP seminars are provided for Mitsubishi MU-2 operators. The Japanese-made Honeywell TPE331-powered turboprop twin has been out of production for two decades, but is still heavily supported by MHI, including the free seminar series conducted biennially.

TAS’s airplanes carry backup portable GPS and radio transceivers, Cannon said. They also carry survival equipment. Cannon said, “You may be flying to a warm-weather environment, but you could be passing over areas where the temperature isn’t as hospitable. Should something go wrong, you might have to walk out 10 miles or more. If you’re not prepared for that, you’ve had it.”

Cannon further projected that a handheld transceiver could summon help from a passing aircraft, and the GPS could provide exact coordinates for the rescue effort. Still, he admitted, “If you polled 100 turbine aircraft operators, I bet you’d find only one or two who carry a survival kit on board, and not many more who have a handheld radio or GPS in their flight kit.”

In the past several years, there have been a few cases where handheld radios could have made a dicey situation a lot less harrowing. In 1998, a medevac flight in a Learjet 35 lost all electrical power over Canada and had to make an emergency letdown through clouds–fortunately with a happy ending. One of the pilots carried a handheld radio, but confessed the battery had been allowed to go uncharged.

Several years ago, John Travolta’s GII reportedly suffered an electrical failure on a night flight from Florida to Maine. The airplane descended through clouds somewhere in the Washington, D.C. area for a safe landing, though an emergency radio could have kept pilots, passengers and controllers a lot calmer. This happened well before 9/11, and it begs the question of how today’s security forces would have reacted to a business jet going suddenly quiet and transponderless over the nation’s capital.

Finally, in the early 1990s, a charter pilot flying a Piper Navajo Chieftain to Connecticut from Atlantic City, N.J., experienced a catastrophic left engine failure that disintegrated the cowling, causing so much drag that the surviving engine could not maintain altitude and he was forced to ditch in the cold ocean several miles south of JFK International Airport. Rescue helicopters and Coast Guard vessels would have located the floating passengers and crew much more quickly had they been able to communicate with a handheld radio. The pilot resolved never to fly without one again.

The proliferation of cellphones has done a lot to lessen the need for handheld transceivers as emergency equipment. News accounts have cited private pilots who used cellphones to call ATC facilities after power failures in flight. But most pilots and controllers would agree that trying to locate the correct telephone number is a less desirable task while under stress than simply using a handheld to contact the controller on the last assigned frequency–or even calling on 121.5 for emergency assistance. There is always 911, but coordinating with ATC would take time. Pilots and controllers would also agree that having access to an external-antenna connection for the handheld improves reception and transmission capability considerably.

Handheld GPSs have no such mainstream counterpart, however. An interesting debate involves asking a group of pilots which they would rather have after an airborne electrical failure–ATC communication or navigation guidance. The answer may well be divided along the lines of “where the failure occurs.” In a dense traffic environment, most pilots would rather be able to talk to controllers first, then work out vectors later. In more sparsely populated areas, pilots might be more inclined to want to know which way to go to safety and let ATC figure out for itself that the radios and transponder have gone silent.

Even if a portable GPS is not considered necessary for emergency backup in the airplane, it could come in handy on the ground. Some of the most recently introduced handheld GPSs are designed to be dual-function aviation and street machines. One example is the Garmin 196 ($999 base price) with its $299 street option. The aviation database is internal and can be updated via the Internet. But the street information is contained in a plug-in card. The street package includes a CD with the North American database, including streets, service areas, points of interest, restaurants, shopping and much more–too much to fit onto the up-to-128-Mb (64-Mb is standard) plug-in cards that go into the unit. When traveling to a different part of the continent, the operator would erase the datacard and download the new geographically appropriate information for the trip.

Anyone who has operated a car with GPS installed knows that the route-calculation software is imperfect. In the case of the Garmin, roads are categorized without regard for signal lights or density of traffic. As such, the machine essentially regards a two-lane country road the same as a downtown street when it comes to recommending the best route. The prevailing wisdom dictates letting GPS be your guide if you have no idea how to get where you’re going. It will get you there, eventually. But don’t expect the GPS to find any shortcuts around traffic jams.

For pilots, even a non-street-capable GPS can be a godsend. After finding that recommended restaurant way out of the way, it can sometimes be difficult to relocate the airport–and specifically the FBO where you left your airplane with all its sophisticated nav equipment. Even if the GPS has no street information on it, punching in the FBO parking lot as a new waypoint can point your nose in the right direction. You’ll at least know that it’s over “there” and 1.2 nautical miles away. If the moving map is equipped with a “bread crumb” tracking device, you’ll be able to retrace your route.

So even if a handheld GPS isn’t considered a safety feature, it can be considered a convenience feature. And if it gets you back to the airport on time just once when you might have left your boss waiting, it could be worth its weight in job security.