February 2003 111
GOOD-BYE, FRIEND: Two days before
his 77th birthday, Jim Clem passed away
after more than two weeks in the hospital.
Initially he had an intestinal blockage that
had to be bypassed. He was always in
fragile health, suffering from arthritis and
scoliosis most of his life. Before he met
his beloved Fran, he lost a lung to
pneumonia before medical science knew
how to deal with it.
It was long after that when Jim and
Fran met at Southern Methodist
University. They courted in his Cessna and
Cadillac, and produced two sons: Jimmy
and Mike. There are a total of six
grandchildren.
I was privileged to ride in that Cessna
when Jim and I went to Longview, Texas,
to enter an annual AAA contest. Jim’s
Speed models and my Stunt and Combat
models rode in the backseat, and the
toolboxes were stowed in the luggage area.
From that time on, Jim and I went to
contests across the country. This continued
after we both started flying Indoor; we
either drove (to the US Indoor
Championships [USIC]) or flew on
commercial airlines (to the Kibbie Dome).
We flew at the Bedford Boys Ranch until
the site management stopped allowing the
air conditioners to be turned off.
The loss of Bedford removed the last
local site where we could test-fly safely to
prepare for USIC. Until the YMCA raised
the family membership rates, we flew
models in the “Y” gymnasium. Jim turned
to extensively test-flying MiniStick
models in the 14-foot-ceiling recreation
room at his house. I gave up on trying to
do any meaningful model-airplane
development and became an advisor at the
personal robotics club, where my years of
Bud Tenny, Box 830545, Richardson TX 75083
FREE FLIGHT INDOOR
This is Jim Clem’s revolutionary Federation ROG. These are Jim Clem’s experimental MiniStick models.
Jim Clem (L) and Joe Kehr at USIC. Text has more about Jim. Dave Linstrum photo.
instrumentation and test experience could
be put to good use.
Meanwhile, Jim continued to
experiment with propellers and model
configurations. When the Federation ROG
was conceived by someone on the East
Coast, he began to experiment.
Jim ultimately developed the model
shown in a photo. He extended the
motorstick to 36 inches and braced it to
prevent bowing. Wing, tailboom, and
landing gear plugged into tissue sockets to
ease packing. This extreme configuration
came with a price: the center of gravity
and wing incidence had to be set precisely
to avoid tail chasing on the ground or
severe stalling.
Jim read modeling and aviation
literature extensively for ideas to try. The
high-thrustline configuration shown in one
photo was one of his “original ideas”
gleaned from something he read.
The model on the left had a long,
underslung fin which stiffened the light
tailboom, and twin rudders gave adequate
pattern control during the power burst,
02sig4.QXD 11.21.02 1:31 pm Page 111
which gave a smooth pattern not seen on most MiniStick models.
The up-slanted motorstick on both models lowers the stabilizer,
hopefully getting it below most of the wing downwash. The
model on the right shows the same basic model without the
subrudder.
By flying the same propeller and motor on both models, Jim
could make direct comparisons between the configurations. That
photo shows different propellers on the two models, and Jim
could swap propellers between models for testing.
He kept copious notes on everything about the flights. He
recorded air temperature at floor level, drift patterns, what batch
of rubber was being used, and motor dimensions (cross-section,
loop length, and loop weight). We were never able to figure out
how to
reliably measure air temperature at various altitudes above the
floor.
Recent advances in electronics would have made reliable airtemperature
profiling easy. It is a shame that Jim didn’t live long
enough to take advantage of these advances! He would have been
overjoyed to be able to record that data; he always had plenty of
paper for his records!
The models were extensively documented during all these
tests. Turns in, turns backed off, launch torque, launch turns, turns
left after touchdown, flight time, and when the model reached the
ceiling (or when it stopped climbing or hit the wall) became part
of the record.
Another photo shows a common scene at recent USIC
contests. Jim Clem and Joe Kehr made several trips there
together. Both spent a great deal of time building and planning for
this contest every year. Whatever vehicle they drove was always
packed full of models and equipment.
Bob Champine: Those who remember Bob Champine may know
that he suffered a stroke sometime ago. He is slowly making his
way back with speech and physical therapy. Gloria Champine
furnished these Web sites that tell about much of his career as a
NASA test pilot. There are two URLs for Bob’s Web page:
http://hometown.aol.com/GRC6431/myhomepage/index.html and
http://members.aol.com/_ht_a/GRC6431/myhomepage/.
“Testing the First Supersonic Aircraft: Memoirs of Bob
Champine” is at www.oea.larc.nasa.gov/PAIS/Supersonic.html
and Bob’s Dryden Pilot Biography is at
www.dfrc.nasa.gov/PAO/PAIS/HTML/bd-2001-01-31.html.
There is a lot of information available about this great aviator!
New Rules Cycle: A new three-year rules cycle began on January
1, 2002. As of this writing (October 1, 2002), the deadline for
The propeller rotates to reveal blade-angle measurement.
The propeller holder swivels to continue angle checking.
The blade-angle checker breaks down for compact storage.
This propeller-blade angle checker is portable. Text has details
about propeller pitch, which is key to model performance.
112 MODEL AVIATION
02sig4.QXD 11.21.02 1:32 pm Page 112
submitting rules amendments and new
rules proposals has just passed.
After review by the chairman of the
relevant Contest Board, all new proposals
will be published in Model Aviation. When
that happens, read the proposals affecting
the classes you fly and contact your district
Indoor Contest Board representative at the
following addresses, and tell him if you
like or dislike each proposal.
• District I: Ray Harlan, 15 Happy Hollow
Rd., Wayland MA 01778-3521; Tel.:
(508) 358-4013; Fax: (508) 358-4013; Email:
[email protected]
• District II: Douglas Barber, 23 Rabbit
Run, East Hampton Township NJ 08060;
Tel.: (609) 518-7160; E-mail:
[email protected]
• District III: Walter Van Gorder, 5669
Victoryview Ln., Cincinnati OH 45223-
4661; Home tel.: (513) 922-3351; Work
tel.: (513) 922-3351
• District IV: Don Srull, 941 Kimberwicke
Rd., McLean VA 22102-1307; Tel.: (703)
893-5071; E-mail:
[email protected]
• District V: Richard Mac Entee, 2409B
14th St. Dr. N.W., Palmetto FL 34221-
6110; Tel.: (941) 729-1524
• District VI: Lawrence Coslick, 4202
Valley Crest Hills Dr., Saint Louis MO
63128-1831; Tel.: (314) 892-3803
• District VII: Gordon Wisniewski, 4790
Stratford Dr., Greendale WI 53129-2015;
Tel.: (414) 421-3696
• District VIII: Bud Tenny, Box 830545,
Richardson TX 75083-0545; Tel.: (972)
235-4035; Fax: (972) 235-7115; E-mail:
[email protected]
• District IX: Stan Chilton, 3010 Grail St.,
Wichita KS 67211-3816; Tel.: (316) 686-
9634; Fax: (316) 264-5721; E-mail:
[email protected]
• District X: Clarence Mather, 2358 Tam O
Shanter Ave., Bishop CA 93514-1944;
Home tel.: (760) 872-1127; Work tel.:
(760) 872-1127
• District XI: Andrew Tagliafico, 10039
S.W. Quail Post Rd., Portland OR
97219-6368; Tel.: (503) 452-0546;
E-mail: [email protected]
Propeller Pitch: The pitch of a propeller is
key to model performance. Two factors are
important: actual pitch and equal pitch
between the two blades. If the blades have
unequal pitch, the propeller will wobble. This
reduces thrust and upsets model trim. Before
trying to get a new model into the best trim,
make sure the propeller is running properly.
After that, it will be easier to adjust the model
so that it flies to its maximum potential.
When you build the propeller, take
special pains to build in the pitch you think
you need. Test-flying may suggest a lower
pitch is needed, or the model may seem to
stall easily. If you have a smaller propeller
or can borrow one, check out the stall
recovery. If it performs better, the new
propeller may be suffering from tip stall;
that is, the propeller itself could be stalling.
So before building a new, lower-pitch
propeller, you twist the propeller spar to a
lower pitch into each blade and fiddle with it
until it runs true. In the case of suspected tip
stall, you twist the tips to a lower angle and
try again. You want to know what pitch the
propeller is now, but how?
Since you tweaked the propeller, only
measuring the blade angle at several stations
along the blade will properly define the
propeller. One photo shows a MiniStick
propeller being checked for equal blade angle.
The wire is lifted until it just touches the edges
of the blade. Then, as shown, rotate the blade
aside so the scales can be read. Compute the
blade angle using tan (y/x). The pitch at that
blade is: pitch = 3.1416 x tan(y/x).
As shown, the propeller-holding post can
be leaned outward to allow the second
propeller blade to be rotated into place for
angle checking. Another photo shows how the
angle-checking fixture breaks down to allow
compact storage in your toolbox. MA
