Old-Timers - 2010/02

130 MODEL AVIATION
The 2009 SAM Champs
Old-Timers Bob Angel | [email protected]
Also included in this column:
• Covering undercambered ribs
• An aerodynamics lesson
• Aviation heroes
• Electric Valkyrie
Above: The author (in white shirt) takes his Stardust
Special up at the ’09 SAM Champs; timer Ralph
Cooke break-dances to attract thermals. The dark
edge of the dry lake is more than a mile away. Ned
Nevels photo.
Right: The Lanzo Bomber is popular worldwide.
Australians Max Rixon (L) and Bob Raadts prep for a
flight at the SAM Champs. Not shown is Allan
Laycock, who was the third Aussie team member.
Below: George Shacklett holds his newest Valkyrie.
Check out that authentic, intricate wing
construction. The Valkyrie is a 1937 Carl Goldberg
design.
THE 2009 SAM (Society of Antique
Modelers) Championships was flown in
September on the dry lake in Boulder City,
Nevada. The site has almost unlimited and
unobstructed space for FF models and a
flat surface for safely following them on a
chase bike. The RC competitors enjoy a
spacious landing area, which they are
required to land inside to complete a score.
We enjoyed mild weather all week
except for Tuesday, when the wind blew
all day and few flights were made. The
events were rescheduled for Wednesday or
Thursday.
It can be a busy week if one attends all
of the social affairs associated with the
contest. There’s barely enough time after
flying to clean up and get to the Mondayevening
collecto (swap meet), concours
judging and voting, and engine raffle; the
Tuesday bean feed; the Wednesday SAM
membership meeting; and the Friday
banquet ceremonies.
The meet headquarters was the Fiesta
Henderson Casino Hotel, which is well
02sig5.QXD_00MSTRPG.QXD 12/21/09 10:33 AM Page 130
equipped with meeting rooms, banquet
facilities, etc. Perhaps fortunately, our
modeling-related social activities didn’t
leave much time for us to transfer our life
savings to the casino.
Each year, a Model of the Year is chosen
for special recognition and awards. The
entire line of Comet Model Company
designs was chosen for 2009. The highestscoring
Comet model in any of several
preselected events was given an extra award.
Nancy Kapitanoff was a guest speaker
and presented her documentary film about
the Comet Model Company. She’s a
descendent of a man who was active in the
company. The film had many scenes from
those early model meets that had hundreds
of fliers and spectators in attendance.
The flying activities are the highlight of
the SAM Champs, but many people attend
solely for the opportunity to socialize and
reminisce with those who produced the
history we’re re-creating. The flying events
are too numerous to list here, but a complete
set of contest results, including aircraft
flown, is available for viewing on the SAM
Web site.
The SAM Champs alternates every other
year between the Nevada site and the AMA
National Flying Site in Muncie, Indiana. The
2010 Muncie event will take place
September 13-17.
Featured Models of the Year are the
Kerswap for Power and the Gollywock for
Rubber. Both are of simple, built-up balsa
construction, with plans and/or kits readily
available through resources listed on the
SAM Web site.
“Undercamber” is a familiar term to oldtime
modelers, but it may be part of a
foreign language to ARF pilots and others
who have flown only modern airplanes.
Undercamber describes that concave shape
on the bottom surface of some airfoils. It’s
seen mainly on older aircraft ranging from
the Wright Brothers era to roughly World
War II.
I have a construction tip for covering an
undercambered wing with iron-on film. It’s
well known by most old-timers but it might
be new to those who are doing this job for
the first time.
The film will struggle to pull itself
away from the rib bottoms, so you’ll want
smooth edges on those for good adhesion.
Applying a thin coat of dope or other
adhesive that soaks into the wood is a good
idea. Make sure you vent the wing
throughout with escape holes, to prevent
trapped air from expanding and loosening
the covering.
Begin covering the wing bottom by
sealing only around the outer edges, so that
it initially looks flat. Then use a small,
wetted soft cloth to closely follow the tip
of the sealing iron as you press the
covering against each rib, moving from LE
to TE.
You’ll be pulling the iron tip during
this operation rather than pushing it. Move
slowly to keep the covering pressed in
place until the cloth has cooled and set the
adhesive.
Rather than working progressively from
one end to the other, I usually begin with a
rib in the center of the span. Then I continue
dividing the remaining area in halves as
closely as possible. This should result in the
least distortion.
Shrink any wrinkles in the open areas,
using the iron with a very light touch while
avoiding reheating the ribs. A heat gun isn’t
recommended here.
The aerodynamics of undercamber is a
subject I don’t usually feel qualified to
tackle. But an occurrence at the SAM
Champs resulted in some experience added
to my “practical application” knowledge
base. It was also a subject I’d never read
about or heard discussed.
The second flight of my 1/2A Texaco
Playboy Jr. was basically out of control,
both during the power run and the glide. It
was porpoising badly; i.e., alternately
stalling and recovering.
I was fighting it with the elevator the
whole time, and when I gently applied
rudder for directional control, it made things
worse. The model made a reasonable
landing, considering the conditions.
I inspected for anything loose or rattling
inside and then checked the controls by
cycling them while applying light pressure
to the surfaces. This was followed by a radio
range check. Since I didn’t find a problem, I
foolishly elected to fly again.
On the next flight, the model was even
less controllable and, to make matters worse,
it wandered into a strong thermal while still
under power. The thermal took it higher and
downwind as I lost the struggle to control it
and keep it within the field boundaries.
This time, a closer inspection revealed
that the undercamber covering had released
across the whole center-section of the wing.
That’s slightly embarrassing after I just
posed as an expert on undercamber adhesion
in the previous section. The only thing I
hadn’t done was apply sealant to the bottom
rib edges for better contact before covering.
But the Playboy Jr. is probably 20 years
old with hundreds of flights under its belt.
Also, the bottom center-section was covered
with black film, which is more subject to
heat absorption than lighter colors. And
considering occasional storage in a warm,
closed vehicle, the loss of adhesion is not
surprising. The wing was vented to prevent
pressure buildup.
So what happened? Apparently a model
that is properly trimmed with undercamber
becomes severely tail-heavy if the
undercamber is suddenly released.
And since the covering became loose, the
airfoil bottom might have been changing
shape during the ups and downs of continuous
stalling. If any of you aerodynamicists can
verify or add to this discussion, I’d appreciate
your comments.
Every sport, hobby, or art form has its socalled
heroes, consisting of those who excel
and inspire others in the activity. Are you old
enough to remember “The Schnoz” (Jimmy
Durante) playing piano while singing,
“There’s Toscanini, Iturbi, and me, we’re
definitely the big three”?
Aviation has many heroes, as does model
aviation. The AMA, SAM, the National Free
Flight Society, and other SIGs have halls of
fame. SAM inducts new hall of fame
members as part of the banquet that concludes
SAM Champs week.
When I lived in Bremerton, Washington, a
couple of local heroes were Henry “Hank”
Cole and Chuck Hollinger. Our model club
consisted mostly of high school teens who
were struggling to master the mysteries of
flying those aircraft. Hank and Chuck were
accomplished “older” modelers who owned a
hobby shop across Puget Sound in Seattle. We
had read their names in magazines when they
were associated with contest wins and model
designs.
I’d met the two fleetingly and only once in
the late 1940s at a contest we held at the local
airport. The club had been enthusiastic for
weeks after learning that Hank and Chuck
were coming to our meet. They didn’t
disappoint and put on a nice demonstration,
while winning several events. I corresponded
briefly with Chuck before he passed away a
few years ago.
Then at the 2009 SAM Champs bean feed,
a man sat down beside me and introduced
himself as Hank Cole. What a nice surprise
after approximately 60 years!
It led to the kind of dinner conversation
and experience one hopes for during the
event. Another surprise came later in the
week, when I learned that Hank was being
inducted into Model Aviation Hall of Fame
during our banquet ceremonies.
George Shacklett of Knoxville, Tennessee,
sent me some photos and a description of his
newly completed and flown electric-powered
Valkyrie. He is shown in his back yard, but
behind him is a city-owned and -maintained
field where he can fly. We should all be so
lucky.
George believes that his is probably the
first full-size Valkyrie to be electrified, and I
have to agree. He also has a Forster .99
engine-powered Valkyrie, which he built
earlier.
Being a practical sort, George uses the
same wing for both models. When you
examine that built-up structure, you might
agree that most of us would become
practical in a hurry before constructing two
such wings. MA
Sources:
SAM
www.antiquemodeler.org
132 MODEL AVIATION
“What a nice surprise
after approximately
60 years!”
02sig5.QXD_00MSTRPG.QXD 12/21/09 10:33 AM Page 132