On course for some good fun!

When Pete Wells came to the field a week or so ago, he brought his very nice J3 Piper Cub. It's a lovely model, about one-fifth scale, 72" wingspan and fitted with an SC52 4-stroke engine and a very nice hand-made prop of Pete's making - he couldn't remember the kit, but it was of Chinese origin.

" There's something here you might like to take a picture or two of ", he said, and when I looked in to the very spacious cabin area of the model, nestled in above the receiver was a neat little GPS receiver, about the size of a mobile phone, which he then removed for the picture on the right (click it for an enlarged view). It runs off a couple of AA batteries and weighs 5·3 ounces with batteries.

The receiver in question was a Garmin eTrex Summit with a whole variety of functions, including a barometric altimeter, that made it ideal for use as a flight data recorder, and that was what Pete wanted to try out, with Martin as the pilot.

After tucking the Garmin away again in the radio bay, Martin flew the Cub for eight to ten minutes, taking her up as high as safe visibility would allow, flying plenty of circuits and a fair bit of speed, before bringing her in for a nice, gentle, landing.

On the left, you can see the receiver still in the plane just after landing and displaying a graphic of the ascent characteristics of the flight. With the gadget removed, Pete then ran round all the various items of data that had been recorded.

A quick scan round some of the recorded data data revealed that the Cub had ascended to 1609 feet above ground level, had flown at a maximum speed of 63 m.p.h. and covered a distance of 6·64 miles. The track display on the small screen was just a mass of criss-cross lines, difficult to sort out with such a density and not too meaningful when zoomed in. Pete had switched the receiver on long before take-off, so the recorded trip time was not particularly useful.

Back at home, though, Pete was able to download all the data to his computer and he then sent me a couple of the numerous print-outs that were available.

This thumbnail shows the full track of the flight nicely superimposed over the Ordnance Survey Map of the locality. Click the small image and you will see the full detail of Martin's flight as he wove his way over our field. He clearly flew no particular pattern, but it would be fun to see just how accurately you could trace and repeat a nice rectangular pattern, perhaps with a figure-of-eight neatly fitted within it, as Pete had apparently tried some time ago using another GPS receiver.

On the right is a copy of the print-out of the track properties. The mass of detail on this is impressive, with information recorded of the time, altitude, length, duration and speed of every leg of the flight.

“What's the point of doing it", you might say, to which the answer is, “It's just darned good fun!"

If you want to know more about the Garmin range of GPS instruments, they have a website at www.garmin.com