Scienceguyorg Ramblings: Memorable RC Thermal Flights

Monday, August 10, 2015

Memorable RC Thermal Flights

This weekend I continued testing of the Spektrum telemetry and vario installed in my Gentle Lady 2-meter sailplane. My previous blog post about telemetry had a large number of views. Last Saturday I flew in not so great conditions until it was time to leave, and then the weather was improving. There was only one flight where the glider was climbing slowly in a thermal but I lost the lift before getting very high. I did get the vario unit changed to output in feet instead of meters however.

Gentle Lady in Flight

Really Low Wind

Sunday there was a forecast of sun and very low wind of only 2 mph in the afternoon. This time I used my longer hi-start with heavier tubing. On the first launches I did not pull back near enough to get much altitude at all but I did not want to break the wing. With an older larger glider I had, that is exactly what happened, pulled back just a little farther to get more altitude and snapped the wing. The heavy tubing on this hi-start also seemed to be hard for a 2-meter glider to lift launching into almost no wind. Many of the launches were 100 feet or less.

Heavy Tubing on Hi-Start

Result of Too Much Tension on Hi-start

After at least a dozen launches I managed to launch to 120 feet and encountered lift right away. The vario was constantly beeping. I kept the glider circling as smooth as possible and it kept gradually working upwards. As the altitude passed 200 feet or so the rate of climb improved somewhat also. I was starting to draw attention to a family that was bike riding in the area and turkey vultures flew in closer to join my glider briefly. The last altitude that I remember hearing was a little over 390 feet, after that the altitude was slowly decreasing. I started flying in a different area of the field looking for another thermal.

At about 60 feet of altitude the vario started beeping again so I started the glider in a circle. Circling rather tight seemed to work better now. The highest it reached from this thermal was about 260 feet but it was such a thrill to climb from a fairly low altitude. Soon after landing the gaps between clouds closed in and the sun went under. I had one the nicest thermal flights I had in a while so decided I had enough flying for the afternoon. Whether having the vario helped on this flight I do not know, it did help to be able to tell the story without having to use complete guesses to the altitude of the glider at different points in the flight.