|
This is part two of a series
from the March 1957 issue of American Modeler magazine that briefly introduces
a dozen winning free flight models and comments from their designers. Current day
modelers who like to fly the vintage (old timer) airplanes might pick up a useful
tip from the masters of the golden age of free flight. Materials have not changed
a lot since then, other than maybe the use of carbon fiber in the airframe, and
no doubt engine technology has gotten better, but the fundamentals of trimming for
the powered and glide portions of free flight pretty much remain the same. Weather
and the basics of flight are the same today as they were in 1957. A lot of top contenders
in any sport are reluctant to divulge their secrets to success, so revelations like
these are priceless.
Symposium on Free Flight Adjustment Part II
Here are more contest-winning design and adjustment secrets revealed by some
of America's top free flight champions. These came in response to a special survey
made by American Modeler magazine. See our January 1957 issue (pages 16, 17 and
18) for background information on this cross-country check.
Additional construction details, and complete data on power plants, plugs, fuels,
etc., on many of the following flyers' National contest-winning model aircraft will
be found in the special section "Analyses of National Modelplane Winners - United
States Aero Championships of 1956" in the 1957 Edition of Air Trail Model Annual.
Richard McGrath
 This Long Beach, Cal., flyer won first
place in Class B Open at 1956 Nationals with time of 28:35.1. Says all his models
are alike, 2 deg. difference "in wing and stab and 8 deg. down-thrust. Uses left
rudder and stab tilt for glide. Hand glides to determine proper incidence, and likes
a very slight left turn. Changes both wing and stab incidence to correct glide but
if it takes too much or affects power, adds weight. Uses 2 or 3 sec. engine run
on Half A models, 5 or 6 sec. on all others for initial test flights. Slightly rich
mixture and plugged intake when possible. Alters thrust to correct severe turn,
corrects loops and wing overs with downthrust. Prefers to stick to one size prop
for each engine. Has tried changing pitch but reports it doesn't affect his models
enough to warrant its use. Flys right-left flight pattern but if warped properly
left-left pattern. Believes adjustment is more important if you have good basic
design. If design is bad to start with you have troubles. Recommends medium height
pylon models as easiest for beginners to adjust. Advises beginners not to try to
obtain a perfect power pattern by cutting down on incidence. Use down thrust if
necessary. Admits he has been using it lately and finds climb is just as good and
recovery is better with enough incidence. Also finds this set-up gives getter glide,
more stability. Would advise novice building Half-A model and fly in grassy field.
Then vary all adjustments to find out what happens when you do.
Gene Boyd
Although he resides in Los Angeles, Gene, 15, flys as member of Long Beach Thunderbugs.
In junior events at last National meet, he won 1st Class A free flight, seconds
in A/2 and B, third in C! Says Gene, "The fellow who is responsible for me being
a good flyer is Harry C. Gould who really is a modeler's friend along with the rest
of the Thunderbugs." Flies modified "Sailplanes" with 1/8" positive wing incidence,
about 5 deg. down thrust. Adds 1/2 ounce weight to tail. Flies to left under power
by washing-in left wing panel. Tilts stab, also shifts stab to give wide left glide
turn. Builds stab as light as possible. In this way can add weight in stab if necessary
to trim glide. Alters stab incidence if needed. Claims incidence changes to stab
are more effective. Test flies with 10 to 15 second motor run with half power and
prop on forward. Uses fairly heavy prop that gives considerable left torque. Believes
good design is very important, adjustment know-how is also important. Recommends
beginners use flat bottomed airfoil in wing. Says under-cambered sections are more
difficult to adjust due to tendency to glide in tail-high attitude.
S/Sgt Fred W. Salmon
 Stationed at Whiteman, Mo., AFB, flew
as member of Air Force team at 1956 Nationals taking first in Half-A free flight
open with 14:29.6. Uses 2 deg. positive incidence in wing, zero degrees in stab;
6 deg. downthrust and 3 deg. left on motor. Believes in hand gliding; strives for
very gentle right turn, achieves by tilting stab. Except for experimental models,
C.G. location should not be changed. Makes trim adjustments to stab. Test flies
with 5 to 10 sec. motor run and right-right pattern. Runs engine just above idle
with prop on forward. Says prop on backward does not present a true picture of what
can be expected. Claims even changing brands of props can spin in a model. Never
changes pitch to alter turn. Considers adjustment just as important as good design.
Recommends Half-A to beginners. Feels they will take more punishment than larger
models.
Johnnie Wertz
 Oildale, Cal., competitor took first
in Class C senior flying at '56 Nats with 16:25. Uses 5/8" positive incidence on
wing of his "Ramrod." Zero stab setting. Uses downthrust but tries to stay away
from side thrust. Hand glides and adjusts for slight stall during first flights.
Tilts stab 3/16" and flies in right-left pattern. Uses fuse type dethermalizer on
all flights. Adds weight to nose on fourth test flight to offset extra weight of
longer dethermalizer fuse. Recommends a 12 sec. engine run on 1/2 to 3/4. power
to allow model to gain about 200 feet altitude. In case of severe stall, this gives
dethermalizer chance to pop. Feels propeller plays an important part in final flight
pattern and changes pitch to alter power turn. Believes no model is hard to adjust
if you know what you are doing.
Robert Nichols
 Nineteen year old Meriden, Conn., free
flight fan scored 14:45 in Class B contest at National championships, taking first.
Flies with 3/16" positive wing incidence, zero stab setting. Never uses side thrust
but on models that loop recommends some downthrust. Hand glides for left turn with
nose slightly high. Gets desired glide left turn with rudder and tilting stab. Corrects
glide angle by altering incidence to both wing and stab. Adds weight only if absolutely
necessary. First test flights made with 8 to 10 second motor run at slow speed and
prop on backwards to cut down torque. Flies both a right-left and right-right pattern
depending on type of model. Believes adjustment know-how more important than design.
Glen Carlile
 Duncan, Okla., Balsa Bugs member was best senior
flyer in Half-A free flight at '56 Nats. He works as a machinist. Uses 3/8 to 3/16"
positive wing incidence. zero stab setting; 7 to 8 deg. downthrust and slight left
thrust. Controls glide turn with tilting stab. Hand glides but does not trim for
turn. Prefers glide to left but says it doesn't make much difference whether it's
left or right as long as transition from power is smooth and without spinning tendencies.
Does not use rudder tab. If tilting tab is insufficient, warps wing. Corrects glide
by changing wing incidence. Alters stab if necessary. Says weight should only be
added when model is very nose or tail heavy. Test flies with 5 second motor run.
Low power prop on forward. Recommends a 6-3 or 6-4 prop for 1/2A models. Believes
adjustment and design equally important. Claims hardest models to adjust are those
with no incidence in wing and stab and C. G. at wing trailing edge.
Lawrence H. Conover
 This Cedar Rapids, Iowa designer has produced
numerous models in all types of contest events. A member of America's 1956 International
F.A.I. team, his model was proxy-flown in England to second place. Flies with 2
deg. positive wing incidence, 2 deg. negative stab setting, engine thrust 3 deg.
left and 3 deg. down. Hand glides and flies models in right, right pattern. Uses
tilted stab and washes in wing on inside of turn. Rudder tab for power turn only.
Claims decalage determines power characteristics, says glide can be trimmed by adding
weight. Also makes incidence changes to either wing or stab depending on conditions.
Test flies with 5 to 8 sec. motor run at lowest power with intake plugged and prop
on backwards. Feels prop is important and changes to a lower pitch if model flies
too fast and is hard to handle. Likes right corkscrew climb at 70 deg. angle, flying
up on wing. Believes you can make anything fly, most efficient setup is to design
for specific set of conditions. Claims low powered and slow moving models win more
consistently. Recommends beginners take it easy and make only small adjustments
to control surfaces at one time. Rudder is very critical. Keep a log book with adjustment
information on all your models. Always use a dethermalizer; think before you fly.
Jim Watson
 This Des Moines, Iowa, modeler, only 17, has
racked up a tremendous record in National meet flying: he has participated in every
Nats since '48 winning 4 firsts, 2 seconds and a third place. At the '56 championships
in Dallas he did 13:59.8 in Class A F/F senior to take first. Flies "Spacer" with
3 deg. positive wing incidence, stab at zero. Uses small rudder tab rather than
thrust adjustments. Says this method is not as critical under power. Tilts stab
for glide turn. Hand glides for floating right turn. Prefers adding weight to changing
incidence angles. Initial test flights made with 7 second motor run, rich fuel mixture
and propeller on backwards. Does not change prop pitch to alter power turn. Follows
engine manufacturer's prop specs. Flies right-right pattern on high pylon models,
but flies low pylon types to the left. Believes adjustments know-how very important.
Suggests beginners to F. F. gas start out by building contest type kits of proven
design. Build original designs after winning a few contests. Claims if you can't
adjust someone else's design, you won't be able to adjust your own design.
Dennis W. Alford
 Resides in San Diego, is member of E; Cajon Modelairs
and one of West Coast's outstanding junior (14 years old) competitors. At last Nationals
Dennis won firsts in B, C and ROW free flight! Usually flies "Sandy Hogan" with
3/8 inch positive wing incidence; zero stab. setting; 2·to 3 deg. right and downthrust.
However says these adjustments do not hold true under all conditions. At '56 Nationals
used 1/2" positive wing incidence, 1/16" negative stab. setting, 2 deg. right thrust
and 3 deg. downthrust. For glide turn tilted stab 2 deg. and offset rudder tab 2
to 3 deg. Also recommends floating tab on left wing at polyhedral. Hand glides after
model balances correctly and permanent weight has been added. Corrects glide angle
with wing incidence and stab if necessary. Test flies with no more than 10 sec.
motor run with venturi half plugged, rich mixture and prop on forward. Makes adjustments
as power is increased to keep model in right turn and climbing at a 70 deg. angle.
Believes prop plays an important part in final flight pattern; sticks to same prop.
Claims design and adjustment of equal importance. Uses silk covering on all but
1/2A models. Says extra strength and long life worth extra cost. Advises beginners
to build Class B or C model and use Class A motor. Believes downfall of most beginners
is too much power.
J. R. Hayden, Jr.
 San Antonio Gas Model Association member Hayden
was top man in Class A free flight (adult division) at last Nationals with time
of 17:08. Builds pylon type models with 2 deg. downthrust. Achieves proper glide
angle by altering incidence angles in both wing and stab. Says sometimes addition
of a little nose weight plus added positive wing incidence will increase penetration.
Flies right-left pattern. Prefers tilting stab to control glide turn but also favors
use of floating wing tab. Makes test flights on 8 second motor run at 1/3 power
and prop on backwards if highly powered model. Claims with some models, changing
from 4 to 5" pitch propeller may give better power pattern and more altitude even
though engine will not rev as high.
Bill Hartill
 One of America's top-notch flyers, this Passaic,
N. J., modeler was member of 1955 and 1956 U.S.A. International F.A.I. free flight
teams, also won a position on America's '56 Nordic glider squad! Model shown flies
with 5 deg. positive wing incidence, 3 deg. positive in stab. No thrust adjustments
but may use 1 or 2 deg. right thrust to give right spiral climb. Hand glides for
left turn but says this only determines how good glide is and should be used only
as rough estimate. Prefers tilting stab for glide turn. Adds weight to nose of fuselage
or builds lighter stab to correct glide angle. Flies right-left pattern and uses
rudder tab for final power turn adjustment. Test flies on about 7 second motor run
with rich mixture. If pattern looks good makes all further tests with full power.
Agrees prop pitch affects climb turn but favors prop that gives maximum thrust.
Believes for all-out consistent performance superior design is necessary but proper
adjustment is needed to bring out design's potential. Favors rudders anchored to
fuselage instead of to stab. Claims high aspect ratio wings (12 to 1 or higher)
give real boost to glide on Class A or larger models but ability to roll and thus
keep nose up in spiral climb is impaired. Cautions beginners against starting with
shoulder wing jobs, claims these models require real mastery of rifling tendencies.
Says high pylons with moderate aspect ratio and plenty of dihedral are easiest to
adjust.
|
