Hand-held GPS units like this Magellan 2000, have revolutionized small aircraft navigation, but where can you mount them on a typical ultralight? Gyroplanes are notoriously short of good places to hang gadgets and a gyro like the Gyrobee is much worse than a typical fixed-wing, which often has miscellaneous tubes and struts available.
We had the opportunity to fly with a Magellan 2000 during the 1996 flying season and it was a real help WHEN we could keep it locked! The problems all boiled down to the lack of an effective mounting arrangement.
Lacking a place to put it, the first idea was to use the supplied lanyard to hang it around our necks. Trouble is, hanging antenna-end down, the unit would typically lose lock with one or more satellites, putting it out of business. If you would hold it in your left hand, in the clear with the antenna angled upward, it would eventually lock up, but you had to wait for lock, making it far from convenient or safe. It also meant you had to actuate the different functions with the thumb of your left hand - not exactly easy to do when you are flying a gyro!
The next thought was to use Velcro to hold it down on the left thigh. This made it easy to use the fingers of the left hand to key functions, and it was a lot more comfortable in flight. Unfortunately, the viewing angle was poor and locking was often marginal. The most likely reason for the latter problem is that the antenna probably didn't work very well with the back-side flush up against the old body!
During the 1997 season I had to do a lot of flying without Don around. Usually, when we fly on a long cross-country jaunt, we alternate legs. Since each person only does half the flying, it isn't too hard to remember headings and all the major landmarks for the limited number of legs I would actually fly. This year would be different, since any significant trips would require that I con the gyro on all the legs and that was too much for my fading brain cells! If I wanted to get more than 40-50 miles from home, I had to find a way to mount the GPS so it would work reliably!
The first step was to obtain a mounting kit for the Magellan 2000 - Part number 00-69008-000. This will set you back about $20. It contains all sorts of mounting gizmos for handbars, walls, dashboards, etc., but it still needs help to accomodate an open-frame gyro.
Step two was to fabricate a small thigh-board out of light gauge aluminum sheet. The exact thickness is not critical - it should be thick enough to be stiff but light enough to work easily. Cut the sheet as indicated below:
Basically, we have a simple rectangle with some "ears" at the upper end. Bend the "ears down at about 45 degrees as shown.
To create a "non-skid" backing, I cut up an old computer mouse pad and glued it to the back of the aluminum. I degreased the aluminum and used "Plumbers Goop" to glue the cloth side of the pad to the metal, leaving the roughened rubber side exposed below. Use the same "Goop" to glue a strip of Velcro across the top of the aluminum as shown below:
Assemble the GPS mounting cradle and base, discarding the wall-mount base-plate and U-bolts. Clip the 2000 into the cradle and sit in the gyro with the aluminum thigh board on your left thigh (assuming you are right-handed). Now experiment with the placement of the GPS base plate until you get an angle on the GPS that gives to a good viewing angle from the seat.
Mark and drill the holes for the base, clearing some of the rubber away from the holes to permit the bolt heads to pass. I used 1/2 inch 8-32 stainless pan-head bolts and matching stainless nylock nuts. The bolt heads should be on the bottom, with the nuts on the top of the plastic base plate. The completed thigh board, with GPS in place, should look something like the illustration above.
When I am ready to fly, the GPS strap goes around my neck and I put the unit into a jacket pocket for protection. Once I am in the seat, I put the thigh-board on my left thigh with the base down near my groin. A Velcro strap anchors to the Velcro on the far end of the thigh board, wrapping around and under my thigh and is anchored to the other end of the strip on the thigh board. Secure it snugly, but not too tight. All this should take about 30 seconds. I then pull the GPS from my pocket and clip it into the holder. The neck strap safeties the GPS in case it should ever pop out of the mounting clip (it hasn't done so yet!). The vertical angle can be adjusted to whatever suits you. The mount holds the unit up above the thigh-board and your leg with the GPS angled upward for essentially unobstructed reception.
Strapped in place and ready to go, the Magellan 2000 locks up easily at ground level and holds lock reliably in flight. The angled mounting provides a good sight-line and the keypad is easily operated. The neck strap serves as a safety. Should the unit pop out of its mount, it won't go anywhere and can easily be put back where it belongs.
On the ground or in flight, the Magellan 2000 will now lock up fast and stay locked for the duration of a flight. It is easy to read without any real effort and the controls can be keyed easily with the fingers of your left hand. In short, it works very and makes the Magellan 2000 a perfect companion for long flights over unfamiliar country!
Ralph E. Taggart (
gyrobee@aol.com)