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HP-25 Survives Montana Winter

Posted by Julius Strid on 2 Apr 2000, 9:58 p.m.

I have owned several HP calculators since 1976, when I began college. I bought an HP 21 my freshman year which I still have. It still works. My college fraternity room mate (Steve) bought an HP 25. After we graduated, he went to work in mines and I went on to work on tunnel projects. We both became interested in hang gliding. I learned in Tennessee and he learned in Montana.

Steve was flying from the North Pryor Mountain in Montana in the fall of 1978 and used his HP 25 to calculate glide slopes to see if it was safe to launch on the west slope. This mountain is a "trap-door" fault mountain resulting in a portion of the earth's crust tilting up with a near-vertical side at the fault line and a relatively gentle slope on the tilted portion, looking somewhat like a partially opened trap door, hence the name. The west slope is the more gentle tilted slope and the east side is a nearly vertical 5,000 foot cliff. Generally, it is better to launch over the cliff, but on this particular day the wind was coming up the gentle slope and it was unsafe to launch downwind over the cliff face.

Steve determined that is was OK to launch, so he set up his glider and flew off to the west. It wasn't a very good flying day though, and he couldn't gain much altitude. He had to fly back and forth across the slope in ridge lift between canyons in the mountain face. The canyons on the mountain face are hundreds of feet deep and there is no safe place to land in them. For that matter, there is not really any safe place to land on the western slope of the Pryors, unless you gain enough altitude to fly out further. This didn't happen. As Steve flew across the face, he sank lower and lower, with no place to land, until he caught a wing tip. This tumbled him and the glider into a ball with the glider collapsing around him and resulting in a spectacular crash.

The glider was a mess, and miraculously Steve wasn't hurt at all. This actually happens quite often in hang glider crashes since the tubing collapses and absorbs most of the impact. In the excitement, Steve forgot that he had left his HP 25 out and when the glider debris was packed up and they drove off the mountain, the calculator was left behind. Since it is a long drive up very rough trails requiring about 4 hours of four-wheel-driving from the nearest road, he didn't go back to get the calculator.

The following summer, he decided to go back to fly the Pryor again. When he reached the top, he looked around and found his calculator that had gone through the entire winter, which can be pretty harsh in Montana. Steve brought it down, put a new battery in it, and it still worked perfectly. He still has this very same calculator.


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