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
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"
Designer-author Lipsey adjusts his Honker in Southwestern Championship
meet at Dallas.
Contest-proven Class A/2 Nordic towline glider designed for windy weather competition
appeals to both expert and novice flyer
By M. R. Lipsey
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
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.
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 October 2, 2023
(updated from original post on 7/25/2015)