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GPS - You Need It

Take my first born, but don't take my GPS.

When I produced "GPS - Who Needs It" for Canadian Flight magazine a year ago, I could not foresee that the marvellous unit I discovered then could possibly be improved upon. But I've now been introduced to the Garmin 95XL, a moving map unit with all the latest bells and whistles, including Special Use Airspace displayed right on the moving map.

As soon as it arrived in its pristine new box I promptly set it outside my front door - turned on - while it took 15 minutes to find itself. It had just come from California blindfolded. Normally it is ready in seconds. With that start up formality completed, my flying buddy - pilot and engineer son Ron - and I naturally were required to take the unit flying. (Since my C-172's untimely demise in a windstorm I am relegated to flying my College's Aztec.)

Son Ron plugged the unit into the cigarette lighter for aircraft system power, suction-cupped the antenna to the windshield, and after a wintery walkaround we were ready to navigate. There really was nothing to setting up and working the GPS: turn it on, press the "MAP" button, highlight the airport we wanted to fly to using the cursor, press the "Go To" button, and all the navigation information we could ever need appeared on screen. My son considered me checked out.

We stared at the stack of radios in the Aztec. Suddenly they looked obsolete. This tried and true 1962 Piper Aztec, flown and maintained by the John Abbott College Aerospace Technology Department students and staff, had 2 VORs, 1 DME, 1 ADF, and 1 Loran, which, when all turned on, consume a total of 280 Watts of power compared to the GPS's 3 Watts. All those black boxes rob about 5 horsepower from the engines. Instead of the hungry 60 amp alternators, this Aztec could manage very well on 25 amp ones. Coming to think of it, if we tossed out all those five navigation `aids' and left only the GPS, it could be mounted in a place of prominence so that all aboard could benefit.

The conversation veered to my second Mustang II which is taking shape in the garage. Our dream panel? Transceiver, Flight Computer for the Auto Pilot, and the Transponder. Crowning it all would be the GPS which would be hooked to the wing leveller in the Mustang II. Powering it would be a 35 amp Honda automobile generator, providing the 10 amps of continuous power needed, including strobes. We discovered an added benefit of this GPS to be the simple wiring harness provided for autopilot input. By golly, we agreed, this hand held unit could fly us direct to destination, hands off! Safer VFR flying with an uncluttered panel, and therefore, uncluttered mind. How times had changed.

Ron chuckled as I recounted my latest "true story". I recently brought the Aztec's old Narco Mark 12A into a local radio shop to have it cared for. (Don't laugh - there are many of these units out there.) The technician shook his head, said they don't carry harnesses for those anymore, and why don't I drop it off at the Museum in Ottawa next time I'm there.

All that old radio equipment began to look even more tired. For one thing, it was heavy. We (my co-pilot engineer) added up the weights of our Aztec's 1962 radio equipment, as per the Equipment List. 95 pounds!! Plus the nest of wires and circuit breakers behind the panel which surely weighed another 5 pounds. All that magic may provide job assurance for the avionics people who occasionally need to be in behind there making sure no smoke emanates from those wires, but as in my Mustang II, we figured modernized avionics for the Aztec, including a Garmin 95 XL for navigation, could weigh as little as 8 pounds, and yield as much information and function as the current 95 pounds do. Not only that, but to assemble the information from the existing 5 sources takes brainpower, not to mention eyes looking in five different directions to assemble that information. All necessary information could be on just one screen.

My copilot wanted action, not analysis. I taxied to position, noted 0,7 miles to go on the GPS, and the gear was up by the time the GPS read zero distance half way down the runway. The trick now was to maintain a constant indicated airspeed and to climb in a straight line on the map until the GPS groundspeed stopped increasing. That would translate into the optimum altitude for best groundspeed. Easy, and it sure beat drawing wind triangles. In the meantime the GPS spewed out ETA, groundspeed, track, CDI, distances and Special Use Airspace. Everything on one screen in a kind of heads-up display. We noted with interest how at night the unit would be a life saver: not only was it the most readable instrument on the dash, but there were no needles to interpret or dials to turn or frequencies to find and tune - we were simply following a line on a map. The map scale even changed automatically as we neared our destination for heaven's sake, its resolution revealing more and more detail.

Now the big test. The college only recently paid big money for an engine overhaul on its Aztec and I was very sensitive about shock cooling the newly overhauled Lycoming. With some anticipation we turned back to Dorval and I dialed in the GPS's Vertical Nav feature. Instantly it calculated my required rate of descent from our present position to arrive over the fix at 1500 feet 15 miles out. I lowered the nose and pulled back the power, maintaining the GPS's calculated rate of descent. We waited.

Montreal's restricted Class "C" airspace crawled into view at the top of the map. Still 30 miles out. Nice to have the warning while preoccupied with our descent.

The altimeter continued to unwind.

Ten minutes later, right on schedule, our toasty engines arrived over the fix. Ah! This feature alone should save big bucks.

No time to gloat, the message alert was flashing. We were 10 miles out of a Special Use Airspace. The push of a button and a description of the Montreal Control Zone flashed on screen. A call to the tower gave us clearance to enter. Two miles out from the zone and the GPS signalled again that we were about to enter. Our present course should put us into Dorval's inverted wedding cake in seconds.

The tower took over and vectored us in.

Even before we turned final we were celebrating the virtues of our wonder age GPS. What a pleasure! No longer any eyes back and forth between landmarks and a map, no need to keep a finger following on a map while watching for traffic, guessing at ground position and wondering just how far out from the zone we were. No chance of an inadvertent incursion or fine for flying into a zone. Just follow the line. A call to the tower giving my exact position may have impressed someone. Everything was under control, orchestrated by this hand held unit! Voila. We expert navigators arrived as advertised.

Touchdown was whisper perfect. The map scale read 0,5 miles. My co-pilot son raised his eyebrows and smiled: he was taxiing along the runway using the moving map as eyes. The unit kept us within 20 feet of the centerline. We could have parked the airplane in pitch dark using this GPS.

Our verdict? You may still have to drain your own fuel, but at least navigation will no longer be white knuckle, nor will you blunder into restricted airspace if you do not wish to.

What is left to figure out? Since acquiring my 95XL I no longer even turn on the Aztec's other equipment, not even to impress passengers.

And therein lies the real contribution GPS has made to safety in the cockpit. Eyes can stay outside the cockpit where they belong for a VFR pilot - watching for traffic, analysing changing weather, checking for potential landing sites in case of emergency, spotting towers (since the unit now warns of airspace incursions, will the next model warn us of mountains at our height?) or admiring scenery. Now my passengers can see how many minutes to destination toilets. And they don't think to ask me "where are we?" because somehow with the map displayed they figure they should know where they are.

Check it out: this new technology permits us to navigate following a line on a moving map. It warns of potential Special Use Airspace incursions. It saves panel space. It weighs a small fraction of the old equipment and provides all information on one screen. It provides extra horsepower because the engine isn't struggling to keep up with the electrical load. It can be taken home so that no-one is tempted to remove it from the airplane.

Better still, it permits practice navigation in its simulator mode, helping maintain navigation skills. In this mode you can practice fly your next cross country on your kitchen table, in real simulated time, being alerted to all Special Use Airspace, and therefore possible radio communications. Or if you get bored with C-150 speeds you can dial in up to 999 knots and pretend you are flying your next cross country at SR-71 speeds. This is a major feature of this unit, not only for those who like Flight Simulator flying, but for many of the rusty pilots among us who like to practice our cross-country navigational skills, circumnavigating all those pesky Restricted and Special Use Airspaces, and to do that right in the living room! Or use the GPS cross-country hiking, skiing, snowmobiling, boating, or impressing your car passengers with how future cars will come equipped. (My ultralight friends can have up to 500 private strips programmed into their units.)

Become part of history - fly a GPS - and laugh with your kids ten years from now about how primitive we were "back when." At least for now my son is impressed.

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Frank Hofmann
Copyright © 2003