By Mark Nankivil |
This past weekend, the Mississippi Valley Soaring
Association (MVSA) hosted the 2013 Gateway Soaring Open. The club has been hosting this event for well
over twenty years, drawing fliers in from across the Midwest to compete in a
thermal soaring contest over the two day weekend. So you ask, what is thermal soaring? Thermals are columns of rising, warmer air
that develop s from uneven solar heating
of the ground. As the air above the ground is heated, it develops into bubbles
which eventually break away from the ground and rise into the air. Cumulus clouds are usually the visual cue of
thermals as they form from the warmer, moist air rising to a height where it
cools and matches the surrounding air temperature. The moisture vapor
carried aloft forms the cloud. When you
see hawks, eagles and turkey buzzards circling in the air, they are riding the
column of rising air and climb to great heights before leaving the thermal to
travel further on or go off to look for the next thermal. When you see swallows buzzing around a field and
circling in a small area, they are usually feeding on insects that are being
pulled aloft by a bubble of warm air, making them easy prey for the
swallows. And sometimes you see “dust
devils” which are small, powerful thermals well marked by the dust and debris
that they pull off of the ground. Free
flight and radio controlled model sailplanes (no motors/props) make use of the
same air that the birds use to prolong the time of the model’s flight.
This year’s event had separate contests set for each day
along with a trophy recognizing the best overall score for the full
weekend. Saturday’s contest had a target
time of ten minutes (Sunday’s target time was twelve minutes) with a graduated
landing tape (0 to 100 points), scoring being one point per second up to the
target time and losing a point a second for going over ten minutes. Groups of up to 5 fliers launched within
seconds of each other so that they all flew in the same conditions with the
best time/score being normalized to a 1000 points (plus landing points) and the
other flier’s time/score being a percentage of the best time.
Most sailplane models flown had wingspans anywhere from 3 to
4 meter (118-158”) and typically weighting in the range of 50 to 80
ounces. Models come in two varieties –
“RES” which is rudder, elevator and spoilers and “full house” which usually is
rudder, elevator, ailerons and flaps. Launching
is done with a 12 volt battery operated winch which launches the model up to
500-600 feet from where the model goes out and looks for thermal lift.
I have been building and flying R/C sailplanes for close to
30 years and have thoroughly enjoyed the journey. To build then fly the model sailplane, finding
the lift and then seeing the model sailplane climb in that lift is a truly satisfying
accomplishment. Whether sport flying or flying competitively,
there is something for just about everyone to enjoy.
For more information on R/C Soaring, go to:
Mississippi Valley Soaring Association - http://www.mvsaclub.com
R/C Soaring Digest - www.rcsoaringdigest.comLeague of Silent Flight - http://www.silentflight.org/
Getting Start in R/C Soaring - http://www.rcsoaringdigest.com/pdfs/GSinRCSr.pdf
Mike Johnson launching his molded Pike Perfect sailplane for another contest flight |
Gil Gauger of Vincennes, IN with his new Eagle 4 meter RES sailplane. This model weighs less than 50 ounces ready to fly! |
To fly the R/C sailplane, the flier uses a transmitter much like this one to signal and control the radio equipment in the model itself. The two sticks move the various flying surfaces on the model and the various other switches on the transmitter are used to set up those flying surfaces and various ways of mixing them together to optimize the model for flying and landing.
A molded “full house” sailplane just seconds before reaching the landing tape |
An Aspire milliseconds before reaching he landing tape |
An Aspire sailplane silently coasting over the field prior to landing |
Steve Goulet’s V-tailed Aspire at the moment of spearing the landing zone while his timer watches intently. Note the flaps are down to slow the aircraft to a crawl for the final approach
|
Father & Son duo of Mark & Brendan Miller are both members of MVSA and are frequently sport and contest flying at the field
|
Marc Gellart of Lima, OH flies this beautiful 4 meter span Pike Perfection |
Steve Goulet launching his Xplorer. Note the winch at his feet, controlled by a foot pedal the flier uses to adjust the speed of the tow line being pulled onto the winch drum
|
Karl Miller (Chicago, IL area) & Chris Lee from St. Louis share a few words on the way out to the flight line for a contest round.
|
An Ava Pro RES model silently flies over the field |
Jim McCarthy (Chicago, IL area) intently guides his Aspire towards the 100 point end of the landing tape. Jim won Sunday’s contest.
|
A Supra passes overhead during a test flight prior to the start of the contest |
Chris Lee (St. Louis, MO) used this multi-copter to take a group photo of the contestants for use on the weekend’s trophies
|
A V-tailed Explorer 4 meter model waiting for the day’s first flight |
Marc Gellart (Lima, OH) making sure his model gets maximum landing points |
Gil Gauger (Vincennes, IN) guides his Eagle 4M RES towards the landing tape |
Chris Lee (St. Louis, MO) fully focused on achieving a high landing score. Chris won the Saturday contest. |
A Eagle RES floats over the field during the contest working to make the most of the light lift |
A Soprano RES flown by Bob Gill (St. Louis, MO) circling low in lift over the field |
Two sailplanes working the same thermal during a contest flight |
Brendan Miller (St. Louis, MO) launching his full house Zenith |
A Soprano RES in sunshine… |
(Editor's Note: The Aero Experience thanks contributor Mark Nankivil for this primer on model sailplanes and coverage of the Gateway Soaring Open).
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