FREE FLIGHT DURATION - 2005/05

132 MODEL AVIATION
IMPROVED PERFORMANCE is one inevitability of FF
competition. No matter what the rules-makers do to reduce
performance, modelers figure out ways to make their models fly
better.
For example, the engine run in F1C, the FAI large Power class,
has been reduced throughout the years to limit performance. In the
last 30 years it has gone from 10 seconds to seven seconds, and, for
the last few years, to five seconds.
The 2.5cc engines have become more powerful; gearing has
allowed larger, more efficient propellers; and autosurfaces have
allowed bunt transitions to maximize altitude. Wings have become
longer and thinner, thanks to the use of carbon fiber and other
modern materials. A few models even utilize flapped airfoils or
folding wings to minimize drag in the climb.
F1J was developed as a smaller, lower-performance Power class,
as a parallel to the other mini classes (F1H Towline Glider and F1G
Coupe rubber power). F1J models quickly turned into scaled-down
versions of F1C models. With a dead-air time of well more than five
minutes off of a seven-second engine run, the contest didn’t really
begin until the flyoff.
For the Junior World Championships, F1J was used as the Power
Louis Joyner, 6 Saturday Rd., Mt. Pleasant SC 29464
FREE FLIGHT DURATION
US Junior team member Jonathan Schelp checks his Maverick
F1P. His grandfather Henry Spence waits to start his F1J.
F1P flier Cody Secor with Astro Star at 2003 Nats. He was a
member of winning US Power team at 2004 Junior World Champs.
Amanda Barr made the US Junior F1P team flying a Maverick,
which is now available in kit form. Column has details.
event and F1A and F1B were the Glider and Rubber events
respectively. Within the last few years, a new Power event—F1P—
has been developed to replace F1J as the Power event at the Junior
World Champs. (Juniors can, of course, continue to fly F1J in other
Open contests.)
The rules for F1P are simple. Maximum engine displacement is
1cc (.061 cu. in.), minimum weight is 250 grams (8.82 ounces),
maximum projected wingspan is 1.5 meters (approximately 59
inches), and minimum projected wing area is 26 square decameters
(roughly 403 square inches).
While most FF rules specify a maximum surface area, F1P
requires a minimum area. By restricting the span to 1.5 meters and
requiring a fairly large minimum area, the result is a low-aspect-ratio
wing. (A constant-chord wing to fit the rules would measure roughly
7 x 59 inches, giving an aspect ratio of approximately 8.4:1. Typical
F1J wings have an aspect ratio of almost double that.)
Keeping the aspect ratio low increases drag in climb and glide,
thereby reducing performance—always a goal of the rule-makers. A
low-aspect-ratio wing is also easier to build using conventional stickand-
tissue construction. (Thin, high-aspect-ratio wings require
carbon D-box construction to prevent flutter in the high-speed
climb.)
As are F1A, F1B, and F1C, F1P is flown to a 180-second
maximum; a 10-second engine run is used. (F1P, like the other mini
events, is flown to a two-minute max.)
The F1P rules allow only one incidence change during flight. By
limiting the number of autosurface functions, the rules, in effect, ban
bunt, which requires at least three incidence changes in the stabilizer
(climb, bunt, and glide).
The two-position (climb and glide) variable-incidence tailplane
(VIT) allowed by the rules makes the F1P model easier to build and
trim, while still allowing the stabilizer to move once from climb to
glide setting. An auto rudder is allowed. The typical pop-up stabilizer
DT (dethermalizer) is also permitted.
Although autosurfaces do add a slight level of complication to
construction and flying, they make adjusting the airplane much easier
and safer compared to a locked-up model without autosurfaces. With
a locked-up model, any incidence adjustments affect climb and glide;
VIT allows climb and glide to be adjusted separately. An auto rudder
allows climb and glide turn to be adjusted independently.
Although F1P is a new event, the rules essentially describe a
typical 1960s-1970s Power model. Many designs from that era can
make a competitive F1P with only a few modifications. Just make
sure that the projected wing area exceeds the 403 square inches and
that the maximum projected span is less than 1.5 meters (591⁄16
inches). Any engine up to 1cc (.061 cu. in.) can be used; there are no
special fuel requirements.
To encourage Junior participation in F1P, a number of FF clubs
and individuals across the country are contributing to a program that
offers F1P kits and engines to Juniors who
want to participate in the Junior Team
Selection Program.
“This is a very straightforward program,”
said program administrator Walt Ghio. “If a
Junior gets in touch with me, they will get
information along with a kit.”
After the model is finished, the Junior
verifies completion by sending photographs,
and then he or she receives an engine. The
engine can be used only on an F1P model
and must be returned if the airplane is not
flight-ready within three months of receiving
the engine. A Junior can also purchase a kit,
build it, and then receive an engine.
“They really can’t go wrong with this
program,” said Walt.
For more information about the program,
contact Walt Ghio by E-mail at f1bwalt@
comcast.net or write him at 1380 Elkhorn
Dr., Stockton CA 95209.
This is not an inexpensive program. An
F1P kit can cost more than $100, and the
current price for a Cyclone .061 engine is
$190. The program can only continue with
the generous support of clubs and
individuals. If you or your club would like to
make a donation, contact Walt.
F1P Maverick Kit: Joe Wagner has put
together a kit for F1P based on the Tom
Hutchison-designed 1⁄2A Maverick from the
1970s. Joe’s version is scaled up to fit the
F1P rules. He added a short center panel to
the wing that allows an optional two-piece
wing.
“The Maverick is a low-aspect-ratio
May 2005 133
Also available from Joe Wagner’s The Model Box is a 1⁄2A
Nostalgia kit of Larry Conover Lucky Lindy from the 1950s.
The Maverick kit is designed for the Cyclone .06. Clockwork timer
controls autosurfaces, engine cutoff, and DT.
The new F1P Maverick kit by Joe Wagner features laminated elliptical tips, preformed
pylon, and aluminum engine mount. See column for details.
model and, when enlarged, it needed the
extra flat section to get closer to the allowed
span,” said Joe.
In addition to allowing a more compact
model box, a two-piece wing also permits
shimming one wing half to adjust wing
wash.
“The young fliers need to have
adjustments available,” he said.
The kit features laminated elliptical tips,
balsa-carbon laminated spars, a preformed
and molded pylon, and full-length balsa and
spruce fuselage components. Covering, a
timer mounting plate, and an aluminum
engine mount designed for the Cyclone .06
engine are also included.
The kit price is $129 plus shipping.
Check with Joe about availability. (The first
run of his 1⁄2A Nostalgia Lucky Lindy kit
sold out quickly. Another batch is in the
works.) You can write to Joe Wagner, The
Model Box, 25804 John Hansen Rd.,
Chestertown MD 21620, or E-mail him at
[email protected]. Joe also has a couple
of other kits in development: a 500-squareinch
A/B Maverick and a 1⁄2A Uranus.
Another F1P kit possibility is the Astro
Star 404 designed by Terry Thorkildsen and
kitted by Bob Van Nest. The Astro Star
features a constant-chord wing with unionjack
construction. The kits are available
through the Junior program I mentioned in
the preceding. Contact Walt Ghio for more
information.
NFFS Membership Drive: If you are not a
member of the National Free Flight Society
(NFFS), there’s an added incentive to join.
From now until the end of August, new
members will receive a coupon for a $10
purchase of NFFS plans.
The coupon must be used by the end of
2005 and has no cash value. It can only be
used toward the purchase of NFFS plans.
There will be no partial refunds on plans
orders less than $10. For plans orders
exceeding $10, you pay the difference.
This offer also applies to former NFFS
members who have let their memberships
lapse for at least 12 months. A two-year
NFFS membership is $48 for US residents.
For additional information about
membership options, visit the NFFS Web
site—www.freeflight.org—or contact
membership chairman J.P. Kish. His E-mail
address is [email protected]. The
mailing address is NFFS Membership
Office, 22 Pine St., Homosassa FL 34446.
Go to www.freeflight.org/jlf/New
Members.htm to find the sign-up form.
While you are on the NFFS site, scroll
around and check out the plans offerings.
The NFFS Plans Service is changing to a
digital, print-on-demand system instead of
the old system that required extensive
inventory. Whit Russell has taken over
responsibility for the Plans Service from
Hank Sperzel. (Thanks, Hank, for all the
years of work in this area.) Send your plans
orders to Whit Russell, NFFS Plans Service,
1375 Ridgefield Dr., Roswell GA 30075. MA