Thermal generating

[Bill Cummings]

Hot spring opportunities (Thanks for reminding me, Joe F.)
Minnesota had a lot of shallow swamps. They gave off heat at the end of the day longer than bare ground would.
Switching to thermaling over these swamps near the end of daylight would have me coming out of the air a half hour before sunset.

How about over a power plant water cooling pond
For years Minnesota Power and Light Co. kept Colby Lake from freezing over all winter long even through minus 30 degrees (F).
Sea Gulls would thermal up over the lake to glide 50 miles to Lake Superior which also seldom froze over during the winter.
Many days during the winter with snow covered ground surrounding Lake Superior the Radio data buoys would indicate the wind moving toward the lake from all directions. Sea Gulls could be seen soaring all day without flapping.

[Bill Cummings]

Joe's post, above, reminded me of a 50 plus mile flight from towing at the Las Cruces International Airport and gliding to a town called Hillsboro, NM.
After squeaking over the San de Los Uvas Mountains I made it to the cow ranch on the north side of the mountains. The smell of cow fertilizer had me turning back looking for the stinkiest part of the thermal. Pilots with a good sense of smell (not me) probably have used smell to initiate a search pattern for lift. (The nose knows.)

[Bill Cummings]

Twenty five years ago The Duluth Skyline Sky Dogs signed waivers and a landowner (Tommy Thompson) let us tow
on the dirt roads on the property that he farmed. He had a government grant to drain the peat bogs between
Palisade, Minnesota and McGregor, Minnesota (USA).
For tow roads there were two east/west roads that were half mile apart each four miles long.
Crisscrossing the two parallel east/west roads were three north/south roads each a mile and a half long.
The club pilots named it, "The Black Hole." It put us into the third dimension for many XC flights.

The Black Hole. Minnesota.JPG (42.03 KiB) Viewed 2520 times

Some days even though we had a lot of roads we would find ourselves towing up between cloud Streets.
With winds 10 to 15 MPH the thermals would line up like soldiers and form a line of clouds that indicated
the line of lift that we wanted to follow down wind.
As luck would have it many times the roads were not under the cloud streets but under the clear sinky air
between the cloud streets.
Some days we sunk out after several tows then we would tell the tow driver to tow us up and take a left
at the next intersection. Before the driver turned the corner we would have to fly to the right side of the
tow road in anticipation of the slack we would get when the tow vehicle turned left. That turn would
get us under the cloud street where we would release the tow line and leave, "The Black Hole."
In the drawing below the squiggly line is the approximate flight path for the glider that would make the
90°tow-up work.
Once a thermal has been generated you have to find it.

Car tows HG under a cloud street..JPG (17.31 KiB) Viewed 2520 times