2004 01 gps glitches between the ears

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THE VINTAGE INSTRUCTOR

GPS glitches between the ears DOUG STEWART “Cleared for takeoff, left turn on course approved,” the tower instructed me. Looking to the right to ensure that no one was on final (never trust anyone . . . not even the tower controller), I taxied onto the runway. I applied full power, and as the rudder gained responsiveness I lifted the tail. Shortly thereafter the mains left the runway, and I was on my way back home after dropping my son off to return to school after a weekend home. Observing local noise abatement procedures, I climbed through 1,000 feet MSL before turning left on course. This route was becoming quite familiar to me, now that my son was attending school on the other side of the state from where we lived. I was getting to know all the landmarks that defined the route like the back of my hand. It wasn’t a long trip, just less than 100 miles by 1 mile, but it always took a lot longer going back home into the westerly winds. Back when I used to fly the Mirage for my boss to this same airport, the trip home usually took a little under half an hour. In my Super Cruiser it was more like an hour and a half trip. Thus I was somewhat shocked when my GPS said the ETE (estimated time en route) was more than 12 hours. I also noted that the CDI (course deviation indicator) was starting to drift off to the right, yet looking out the window showed that I was right on course, directly over the highway intersection that lay under the course line on my chart. I checked the bearing to fly, and the GPS said 300 degrees. Hmm . . . I thought my memory was starting to go . . . (those of you that know me, no comments!) . . . Wasn’t the course home a little west of that? More like 286 degrees? While I was looking at the “distance remaining” on the GPS the dawn of recognition started to light up in my brain as the sun started to settle to the horizon out in front of me. The GPS said I had 743 nautical miles to go until I would be landing. As I mentioned earlier the distance from KOWD to KGBR is only 99 nautical miles. The next data field to check on the GPS was the waypoint field. Sure

Thus I was somewhat shocked when my GPS said the ETE (estimated time en route) was more than 12 hours.

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JANUARY 2004

enough, there was the problem. Instead of saying KGBR (Great Barrington, Massachusetts) it said KGRB (Green Bay, Wisconsin). Apparently a little bit of dyslexia had crept in as I programmed my GPS for the flight home. And for those of you who might ask “Were you in a hurry when you programmed the GPS?” the answer would have to be in the affirmative. Had I not been familiar with the route I might not have noticed the problem as quickly, and might have found myself well off course, and perhaps even violating some airspace. Herein lies one of the traps of GPS usage…and there are many traps. Whether because of haste, dyslexia, or a myriad of other reasons it is quite easy to incorrectly enter a waypoint into our GPS. If we do not have a chart with a course line drawn on it, and if we have not plotted our true course and converted it to a magnetic course, we might find ourselves rivaling Mr. Corrigan for “wrong way” honors. Now, although I was in some rather congested airspace underlying the Boston Class B area, I would have to keep my eyes in the cockpit while I reprogrammed the “direct to” waypoint in my GPS. Fortunately I am rather intimately familiar with the use of my GPS, and this would not take long to do, but it would have my eyes inside the cockpit for longer than I like when flying in busy airspace. This is another problem that GPS can create. The problem of too much “heads down” time. Even when a pilot is familiar and conversant with the operation of a GPS, the time it takes to program and edit the GPS takes away from time when our eyes should be looking out the window for that embedded aluminum. And if the unit is new to you, it


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