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Most avid gas free-flighters - even younger enthusiasts - will immediately
the names in this list of Who's Who from a 1957 article in American
Modeler. Carl Goldberg, Stanley Hill, Frank Ehling, John Tatone,
and the others were pioneers of the free flight realm. Unlike many
other model aircraft types, the variety in fuselage, wing and empennage
shapes, engine downthrust and overall configurations is quite wide.
These 11 profile silhouettes, even without top views to show wing
and tail planforms, amply illustrates my point. Even today's winning
model exhibit a similar diversity.
For the First Time ... Symposium on Free Flight Adjustment
America's Top Flyers Reveal Their Contest-Winning Secrets
No matter what new types of model flying may come along, free-flight
will always be with us. For only in free-flight can there be
that feeling, of complete self satisfaction in seeing your model
scream heavenward and then settle gently back to earth unaided
and unguided once it leaves your hands.
Whether you are a true free-flight purist or just enjoy flying
free-flight models whenever the mood strikes you will agree
that in free-flight there is that extra bit of "something" necessary
to get contest-winning performance. No matter what meet you
go to, there is always one model that zooms higher than the
others, glides flatter and probably more important always flies
the same flight pattern. Why? Is it the design of the model?
The engine? Adjustment know-how? Little tricks the champions
use? You've probably asked yourself similar questions hundreds
of times.
To answer these questions for you we queried a number of
top free-flight designers and champions. Among the questions
were those pertaining to thrust line and surface settings, hand
gliding, how to adjnst for turn in the glide and under power,
pros and cons of adding weight to correct the glide angle and
views on incidence changes.
To learn how Champs flight test a new model we asked how
long an engine run on initial test flights, how much power,
what thrust adjustments do they use and what were the adjustments
on their most recent contest· winning models.
For good measure we included questions like: What are your
views on the relationship of adjustment vs. design? Which is
more important? What type of model is easiest to adjust - hardest?
We thank all the champions who participated in our survey
and who for the first time supplied information which had always
been regarded as "top secret." In presenting their views to
our readers we feel that although these may differ considerably
on many points all are well worth remembering the next time
you fly free-flight.
Dr. Stanley D. Hill
First achieved fame flying "Amazon" designed by Mrs. Hill. Latest
is series of "Hammerhead" models. Flew on International F.A.I. free
flight team. Lives in Santa Barbara, Cal. "Hammerhead II" has 2
deg. positive wing incidence, zero deg. stab. setting and zero deg.
thrust settings. Hand glides for loose right hand turn. Gradually
increases turn to safe maximum. Accomplishes turn by tilting stab
and slight right rudder. Says wing warping is dangerous and unreliable
in any hot-power job. Considers wing incidence and C.G. position
as fixed factors which determine model's flight characteristics
and are therefore to remain unchanged, unless desired flight pattern
cannot be achieved with variations of stab incidence alone. Uses
7 sec. motor run for high powered models, 15 sec. if very low powered.
Initial test flights made with very low power, increasing gradually
to 2/3, then to full power. Prop on forward. Tries to avoid thrust
adjustment but has used up to 3 deg. side thrust. Agrees downthrust
is effective in "opening up" looping tendency on low thrust models.
Ineffective on high thrust line models. Flies "Hammerhead" designs
in left-right pattern. Pylons right-right. Believes good design
much more important than adjustment know-how. Considers high thrust
line model easier to adjust due to lack of prop wash effect. Thinks
the more offsets and warps used, the harder model will be to fly.
Carl Goldberg
World's most famous free-flight designer, "father" of all pylon-type
models. Best known pre-war designs were "Zipper" and. "Interceptor."
Currently developing new free flight kit for his Chicago model concern.
Model shown had 1 1/2 deg. positive wing incidence, 1/2 deg. negative
stab setting, no downthrust. Hand glides for very gentle left turn.
Trims model for left, left flight pattern. Uses rudder, tilting
wing and tilting stab in that order as necessary to achieve proper
turn. Says altering incidence angles on proven designs would depend
upon last flight. On test flights, uses 7-8 sec motor run with intake
tube plugged about 80%. When glide is O.K. uses side thrust to alter
power turn. Does not change propeller to alter turn. Believes design
furnishes basic flight capacity. Adjustment corrects errors in design
and building but says it isn't always needed. Advises beginners
to take time and make sure C.G. position and incidence set-up are
as shown on plan. Remove warps by steaming over tea kettle. Work
up gradually from low to high power and get help from experienced
flyers.
Willard S. "Woody" Blanchard, Jr.
Three-time winner of National Model Plane Championship crown
(1954, 1955, 1956). Tremendous contender in any free flight competition;
lives in Hampton, Va. Always uses 5 deg. downthrust, approx. 5 deg.
positive wing incidence and 2 deg. positive stab incidence. Builds
pylon design if power loading is low. Hand glides first then trims
for right-right flight pattern. Uses both rudder and thrust adjustments
for power turn. Tilts stab and uses rudder for glide turn. Corrects
glide angle with stab incidence. Initial test flights begin with
5 sec. engine run with propeller on backwards. Believes prop affects
flight pattern but generally does not change props to alter power
turn. Recommends ample dihedral and use of engine downthrust rather
than tight turn to prevent looping under power. Feels beginners
should build from kits, follow flying instructions supplied by designer.
Says easiest model to adjust is towline glider. Hardest is free
flight gas.
Donald K. Foote
Designer of the "Westerner" free flight kit, author of the well-known
books, "Model Airplane Engines" and "Aerodynamics for Model Airplanes."
Resides in Oakland, Cal. Uses about 1/2" positive wing incidence
in 10 1/4", zero deg stab setting. Believes hand gliding from high
point is very helpful as model can then be adjusted for turn as
well as for flat glide. Strives for turning glide to the left only
because he usually has more than one model at a time and flies all
of them in the same pattern. Says any model that is stable in one
direction is just as stable in the opposite direction, providing
all adjustments are opposite including wing warps. Warps inside
(left) wing slightly, then uses left thrust to turn model to left
under power. Then uses slight amount of right rudder to slip model
toward left to make dihedral more effective. Says rudder should
never be turned past center to left with this method. In working
out an original design, moves the C.G. according to flight characteristics.
Stab incidence is altered to get model to follow flight path and
not present whole bottom as frontal area to flight path. Test flies
on no more than 3 sec. engine run and very little power. Adds adjustments
with each flight of increased power. Claims once model is adjusted
for maximum power it should never be flown on less than full power
since models can only be adjusted for one speed. Finds it unnecessary
to place propeller on backwards. Uses left thrust but never downthrust.
Says down thrust is a dead give away to a bug in the design. Uses
propeller that gives maximum thrust. Claims all his models are adjusted
the same and fly the same, left-left pattern. No matter what the
design, believes even poorly designed models can be adjusted to
win contests but thinks good adjustments coupled to a good design
have a better chance. Considers a high-wing model easiest to adjust,
a low-wing model the most difficult. Says beginners should read
all literature available on the subject to learn why each surface
is trimmed as it is. Thinks it is a disgrace not to know the cause
of a crash.
Richard Sladek
Winner of more PAA-Load contests (and watches!) than any man
in history. This San Diego, Cal., flyer is a consistent winner in
West Coast competitions. Model shown has 2 deg. positive incidence
in wing. Zero stab. Engine has 5 deg. downthrust and 2 deg. right
thrust. Hand glides only in first stage of testing to eliminate
wing stall and achieve left circle. Uses tilting stab and rudder
for turn and if needed floating tab on left wing panel for left
turn. Never warps wings. Keeps C.G. location between 50% and 75%
of mean wing chord and uses 2 deg. positive incidence. Does all
adjusting with stab and engine thrust line. First power flights
are made with 10 to 15 sec. motor run at 1/3 to 1/2 maximum power
and propeller on backwards. Never uses propeller pitch to alter
turn. Flies model in right-left pattern. Believes adjustment is
secondary to a good design. Says no amount of adjusting will make
a poorly designed model fly properly. Easiest models to adjust are
low power to weight models. Claims most beginners start out with
powered models that fly like unguided missiles, the end of the model
being sure and swift.
Carl R. Wheeley
Technical Director of the Academy of Model Aeronautics, winner of
the F.A.I. International free flight competition, lives in Washington,
D. C. Designed famous series of "Senator" contest winners. Does
not: work with degrees. Half-A models use 1/8" positive in wing,
3/32" positive in stab. Class A models 1/4" positive in wing, 1/8"
positive in stab. Class B-C models 3/8" positive in wing, 1/4" positive
in stab. Hand glides and strives for very slight turn. Says almost
every new model turns a little even with straight settings and so
on first flight lets model turn in whichever direction it tends.
Prefers tilting stab to control glide turn. Uses rudder tab and
tilting stab for power turn. Claims it is difficult if not impossible
to determine beforehand right balance point and except for knowledge
gained in flying similar models, it is much a trial and error deal.
Uses variations in stab incidence as final trim after proper C.G.
location has been determined through use of weight. Initial test
flights made with engine running at fast four cycle for 5 to 8 seconds.
No longer recommends putting prop on backwards because of tremendous
difference in turning characteristics when prop is on forward. Tries
to avoid offset thrust adjustments but does use some if rudder cannot
cure defect. Uses same propeller. Claims changing prop often necessitates
complete power flight readjustment. Prefers climb and glide in same
direction whether it be left or right. Believes adjustment is far
more important than design. But says this depends on what a person
considers design to be. Feels changing area of rudder is changing
the design but it is also adjusting model. Claims contest type models
are easier to adjust than scale types.
Frank Ehling
Monticello, N. Y., designer has had more of his free flight planes
kitted than any other flyer. Currently serving as consultant on
design problems to American Modeler. Frank's most recent model uses
1 deg. positive wing incidence, Zero deg. stab incidence, right
but no downthrust. Hand glides from shoulder height or from slope.
Glide turn on high powered model is opposite to power turn. Claims
that with this set-up model does not fall out as transition, but
carries over like hand launched glider. Tilts stab for turn in glide,
uses rudder for power turn. Controls glide angle by placing C.G.
between 70% and 90% of wing chord, then adds positive to stab after
glide is O.K. To retain proper glide adds weight to tail. Makes
test flights with 5 to 6 sec. motor run on high powered models,
10 to 12 sec. on low powered models. Engine wide open, prop on forward
for both types. Uses side thrust to produce one to two circles in
20 seconds. Has never used down thrust. Claims engine governs propeller.
Uses prop that gets most from engine usually a low pitch for glow
plug, higher pitch for diesel. Believes adjustment know-how is just
as important as good design. Easiest model to adjust is large model
with low power but feels best chance for beginner is pylon and high
thrust.
Sal Taibi
Former Brooklyn Skyscraper member, achieved fame before war with
his "Pacer" design. Scored new successes with his "Spacer." Now
lives in Lakewood, Cal. Won International PAA-Load event at 1956
Nationals with time of 15:47.2. Still flies "Spacer" with 2 deg.
positive wing incidence, zero to 1 deg. positive in stab, no downthrust.
Hand glides before first test flight only. Does not fight natural
turning tendency of plane but says "Spacers" generally turn to left
in glide, right under power. Tilts stab to control amount of turn
in glide. Corrects shallow stall or dive by adding weight. Cautions
against adding positive incidence to correct stall. Says this may
adversely affect smooth transition between power on and power off.
Test flies with 10 sec. motor run and about 75% power with prop
forward. If model noses up sharply and hangs, Sal recommends a few
degrees of engine downthrust to get it to fly up instead of drag
up. Chooses prop that lets engine run without "lugging" and controls
turn with rudder. Advises model be allowed to age before testing.
Claims model tested too soon may show completely different flight
characteristics a week later, due to warps induced by additional
tightening of the covering. Easiest models to adjust are those built
without warps.
C. O. Wright
Topeka, Kan., model aviation activity leader, long-time modeler,
former president of A.M.A. Triple-threat man in PAA-Load flying.
Model shown flies with 3 deg. positive wing incidence, zero deg.
stab setting and slightly left engine thrust. Hand glides for straight
or slightly left turn at first. Uses tilting stab for glide turn.
Controls power turn with rudder tab or by shifting entire rudder
or offsets thrust. Flattens glide with wing incidence but maintains
at least 3 deg. for reasonable pull out. Often adds weight for same
reason. Test flights made with 8 sec. run with engine "missing."
Prop on forward. Doesn't like to use offset thrust adjustments but
says, after building, theory is not as important as the performance.
Claims right-left flight pattern is safer with not too much right
spiral. Likes best almost straight-up power path. Admits some of
his best models flew right-right patterns. Believes good design
is important but says two models of same design will vary due to
warps etc., therefore, adjustment is highly significant. Recommends
low pylon designs for beginners as easiest to adjust. Low wing designs
are hardest to adjust. Claims models become more difficult to adjust
as C.G. moves rearward more than 60% from leading edge of wing.
Advises practice of shifting entire rudder instead of using rudder
tab which he claims is more effective but also more dangerous, especially
for beginners.
Dick Everett
Former N.A.C.A. modeler now works for Convair, lives in Chino,
Cal. Many winning designs to his credit; author of American Modeler's
"West Coast Modeling." Uses 1/32" positive incidence for each 1"
of wing chord. Zero deg. stab. setting. Hand glides many times,
strives for left turn through use of tilting stab. Offsets thrust
line to control power turn. Does not use rudder as it may affect
glide turn. Prefers left, right pattern but does not fight model
if it persists in going opposite and flys safely. Invariably adds
weight prior to finishing model to get C.C. forward of 75% of wing
chord. Says all his engines have leaded back plates. If necessary
changes stab incidence for final trim. Initial test flights begin
with 7 to 12 second engine run, low power and intake plugged to
/8" diameter. Prop on forward. Believes in lots of down and right
thrust on high powered models, usually builds in approximately 1/4"
down and right as a start, then alters this to fit model. Does not
believe in measuring in degrees, says they are generally grossly
inaccurate. Agrees prop plays important part in final flight pattern.
Claims lowering pitch gives right turn on pylon models, increasing
pitch will cause model to go left. Does not believe a Half-A model
good proving ground for model design. Says if you scale them up
you are really lucky if they fly. Advises beginners to build the
model to last. Remembers experts taking weeks to trim models, then
flying them and winning for years.
John Tatone
Has qualified for International F.A.I. teams, scored numerous
wins in regional and National competitions, lives in San Francisco.
His timing device in use currently on free flight contest models.
Flies model with 3 deg. positive wing incidence, 1 deg. positive
in stab, right wing washed in 1/4"; 2 deg. left engine thrust. Hand
glides before first power flight. Determines final glide trim after
model has been flown. Does not fight natural turning tendency of
model, never uses rudder for glide turn. Instead uses tilting stab,
sometimes a floating drag tab. Adds weight to achieve proper balance.
Test flies with about 10 sec. motor run, prop on forward. Reports
his ships usually start off with a few degrees down thrust. Adds
more or less depending on power pattern. Believes prop is very important
and uses same prop through test flights. When experimenting with
different props uses short motor run. Thinks pylon type model easiest
to adjust, claims they hold adjustments better. Advises a very small
rudder tab on hot ships. Says rudder tab takes over at high speed,
does not affect the glide.
Additional contributions to this Free Flight Adjustment Symposium
will appear In a subsequent "American Modeler."
Posted January 2, 2016
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