Aaron,

A couple of questions regarding the approach used: For the
calculation, did you use the GPS distance and GPS altitude to
calculate the L/D ratio? The altitude reading of the GPS may not give
you the tolerance needed on such a short run. You should loose only
approximately ~150 feet on a minute run at 50kts. This is not much. I
do not know the tolerance on altitude of GPS except that I undertand
that they are often poor. Extending the length of the run (2-3
minutes) may reduce the height measurement errors.

If you used the altimeter, did you have a vibrating gizmo attached to
the case to "free" the needle? My altimeter only moves 100feet at a
time when left to its own...

As for the distance covered, the GPS again my throw things off if
there was some wind. If the run was up and then down the down, the
wind factor could be eliminated from the calculation. If it was a side
wind, it would be very difficult to extract.

No real answer but perhaps areas to explore. Good luck.

Bastoune