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As open space becomes more and more scare in populated areas all
up and down the East Coast, the Great Lakes region, and similar
sections of the country, free flight activities are increasingly
difficult to contemplate. The same goes for model rocketry. All
of the fields I used to fly from in the
Mayo
(Annapolis), Maryland, area when in my teens back in the early to
mid 1970s were long ago turned into housing developments, commercial
office or retail outlet stores. It used to be a simple matter of
loading an airplane or rocket into my 1969 Camaro and driving a
few miles to a school yard or an empty lot behind a strip mall,
but not so much anymore. Even if you do manage to locate a suitable
flying area, there are usually signs posted warning of prosecution
for trespassing (often made necessary due
to our overly litigious society). School athletic fields
are typically cluttered with soccer nets and other permanent structures.
Whenever I see photos in articles like this one for a free flight
towed glider model, I am struck by the starkness of the landscape
in the background. It seems today you need to me in a Midwest farm
field, in the High Plains, or Southwest deserts to find ample open
areas.
Southwest Champion's Winning Towliner "Honker"
Contest-proven Class A/2 Nordic towline glider designed for windy
weather competition appeals to both expert and novice flyer
By M. R. Lipsey
Designer-author Lipsey adjusts his Honker in
Southwestern Championship meet at Dallas.
After several years of attempting to fly European designed gliders
in the wind and "brick-lifting" thermals of Texas and surrounding
states, it became apparent that while Continental types were suitable
for Europe, something more was to be desired if a glider was to
fly consistently in our weather conditions.
"Honker's" .development was thus begun with three specific points
in mind: i.e. (1) to incorporate the necessary stability to tow
and fly with ease in our turbulent air; (2) to be quick and easy
to build with ample strength to last through several contest seasons;
(3) to be an ideal design with which to introduce the novice to
towline gliders. Honker fills the bill!
Generous dihedral with a 50% C.G. location is combined with an
abnormally large stabilizer to give the glider bounce and quick
recovery when upset. The large stab also gives a more positive D.T.
when you are trying to get the ship down out of that "brick-lifter"
to complete your five flights. The aspect ratio of the wing is reduced
below average for strength, warp resistance, and a belief that high
aspect ratio wings often keep a ship out of a strong thermal. After
observing many gliders, it appeared that when high aspect-ratio
tow liners bumped into the side of a thermal, the wing-half touching
the edge of the lift was kicked-up violently and the ship was actually
thrown away from the thermal. The higher the aspect-ratio, the more
leverage is available for the thermal to act upon. Additional side
area is built into the fuselage to increase tow stability and to
have something to "lean-on" when the glide tightens up with the
speed increase generated in a thermal.
Honker won Lipsey Championship award. Glider
has helped capture 5 hi-point prizes
The "follow-me" tow hook as shown in the sketch is a gadget which
has worked well for the writer. However, this is not recommended
for the novice as it requires towing experience to get the feel
of this device and to be able to adjust it properly. The original
idea behind the moveable hook was to increase tow stability and,
properly adjusted, it performs this function. In addition, it was
found that this arrangement would allow the ship to be towed in
a hunting motion while at the top of the line. Upon feeling lift
with the glider overhead, the glider is towed sideways, turning
the ship toward its normal glide turn. The glider is accelerated
as much as possible at this time. The line is released rather than
attempting to release the ship. The acceleration with the ship turning
into its normal glide path gets additional altitude upon release
with a stall-less transition from tow to glide. Of course, the line
must be released from the reel so that you release only the line
and are not disqualified for throwing the reel.
The writer feels that lack of knowledge in adjusting a glider to
tow properly has discouraged more beginning towline enthusiasts
than any other problem. Ninety-nine percent of tow adjustment problems
lay in the relationship of hook placement to C.G. There is one ideal
hook placement for each glider. This placement is found when the
glider tows straight to the top of the line from the point of release.
(This also applies to the "follow-me" hook).
Rather than take the time to construct an adjustable hook, it
is recommended that a permanent hook be installed with the forward-most
part of the hook 1/4" in front of the 50% C.G. location. Then upon
completion of the ship, the C.G. is shifted to effect the shifting
of the hook, if necessary, and decalage is changed to adjust the
glide. A wandering tow in which the glider always recovers and continues
to follow you indicates that the hook is too far forward. In this
case, the C.G. should be moved forward. (This gives the same result
as moving the hook back). A tow in which the glider always turns
away or has no tendency to follow indicates the hook is too far
back. (Shift the C.G. back).
Construction. The stabilizer and wing should be completed before
the fuselage is begun. This sequence will enable you to fit the
wing and stab platforms accurately and facilitate balancing the
model properly without the addition of unnecessary weight.
The ribs for the stab and wing can be mass produced by making
two patterns of each rib and pinning the correct number of 1/16"
sheet strips between the patterns. All the strips are then carved
and sanded down to match the patterns. Cut the slots for the spars
and leading edge carefully to obtain as perfect a fit as possible.
Slots too small or too large help create warps. The trailing edges
should be notched to receive the ribs. The front of the trailing
edges should be raised from your building board with scraps of 1/32"
to maintain the undercamber curvature.
The 1/16" x 1/2" shear webs which are glued between the "over-and-under"
spars should have the grain running vertically. These sheer webs
add tremendously to strength and warp resistance. Don't leave them
out!
The 1/4" ribs utilized at the dihedral breaks should be aligned
and glued firmly in place along with the other ribs. After completing
assembly of an parts, these ribs are beveled at the correct angles
to butt join the pieces of the wing and stab to form the correct
dihedral angles. Remember the bevel angle for each rib is only 1/2
that of the total dihedral angle. This system of joining parts has
been well received by novices.
The fuselage construction is straight forward and should be completed
without difficulty. The fuselage should be completed entirely except
for the addition of weight and the 1/8" cap sheet over the weight
compartments. The model should then be assembled and placed on a
scales. Add enough ballast to bring the total weight up to 14.5
ozs. The ballast should be shifted until the C.G. is at 50% of the
wing cord. Glue in the ballast and finish.
Adjust your glider carefully, making short tows until you gain
confidence with it. Try to maintain a constant pull on the line
as you tow. This will require you to move faster as the glider reaches
the top. Practice makes winning tows.
Honker Towliner Plans
Full size plans for Honker are part of Group Plan #963 available
from Hobby Helpers (1543 Stillwell Ave., New York 61, N.Y.) - 85
cents. Glider has been duplicated throughout the Southwest.
Notice:
The AMA Plans Service offers a
full-size version of many of the plans show here at a very reasonable cost. They
will scale the plans any size for you. It is always best to buy printed plans because
my scanner versions often have distortions that can cause parts to fit poorly. Purchasing
plans also help to support the operation of the
Academy of Model Aeronautics - the #1
advocate for model aviation throughout the world. If the AMA no longer has this
plan on file, I will be glad to send you my higher resolution version.
Try my Scale Calculator for
Model Airplane Plans.
Posted July 25, 2015
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