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Stabilizer Information Page
17, 1998 - Revised
Retrofit Stabilizer Kit - Parts List and Installation
40S-1420 STABILIZER KEEL EXT ASSY FITS 42MM
(Spectrum, Super Sport, XC, HP AT, Falcon
140/170, Sport AT, Sport E, HPII 88/89, Sport
40S-1430 STABILIZER KEEL EXT ASSY FITS 1.75"
40S-1440 STABILIZER KEEL EXT ASSY FITS 50MM
(Falcon 195/225, Fusion 150)
KEEL EXT ASSY FITS 1.5"
(Sport American 167, HP II before 1988, HP
1, and earlier gliders.)
(1) Dacron stabilizer cover
(1) Keel extension:
1 5/8" (40S-1445)
(1) 10mm stabilizer leading edge tube
(1) 10mm stabilizer trailing edge tube w/corner
(1) Clevis Pin
(1) 10P-1100 small safety ring
Electric drill with 3/16" bit
Tubing cutter or hacksaw
Completely set-up your glider before beginning
Without modification to the keel, the retrofit
stabilizer will lengthen the keel by a little
more than 19". As a result, the
keel would tend to contact the ground first
during an aggressive flare, and might inhibit
the flare as a result. We recommend, therefore,
that the keel tube be shortened prior to the
installation of the stabilizer, and that the
stabilizer oversleeve then be left installed
on the keel. In this way, the overall keel
tube length will be about the same after the
installation as it was before, and the installation
of the stabilizer during set-up for flying
will be simplified. On
all models except the 195 and 225 Falcons,
there is more than 19" of rear keel tube
extending aft of the rear edge of the oversleeve
at the rear keel wire junction. We would
therefore recommend that the keel tube be
shortened at the rear by 19". On
the Falcon 195 and 225, there is typically
about 12" of keel tube aft of the rear
edge of the wire junction sleeve. On
these models, we recommend that the keel be
shortened by no more than 10" (it is
not a good idea to have two oversleeves butt
directly to one another.) If
you would prefer that your keel be a little
longer than it is (in order, for example,
to keep the tips of the sail a little higher
off the ground during set-up and breakdown),
you can choose to shorten the keel tube by
less than the stabilizer will lengthen it,
and as a result have a longer keel after the
CAUTION: No vertical stabilizer should ever be attached in such a way that it is not oriented exactly vertically, and secured solidly against rotation. Gliders with removable rear keel sections must have those sections secured to the main keel with a through bolt or pin prior to mounting and using a stabilizer.
Frame and Cover:
- Decide how much
you will be shortening the rear of
the keel, and measure and mark the
keel at this point.
- If you have
a tubing cutter, you can simply use
it to cut off the keel at your mark.
If you are using a hack saw, use a
bendable straight edge around the
circumference of the keel to guide
you as you trace a line around the
circumference of the keel at your
- Carefully cut
off the keel along the line you traced
using the hack saw.
- Use a file to
de-bur and lightly chamfer the rear
end of the keel tube.
- Slide the keel
extension onto the keel until the
forward bushing seats against the
end of the keel (approximately 5.75").
- Insert the straight
10mm stabilizer trailing edge tube
into either bushing in the keel extension.
Use it as a sighting reference to
exactly align the extension so the
bushings are vertical, i.e.
in line with the rear wire bolt. Lift
the keel to a horizontal position
and sight along it so that the trailing
edge tube and the kingpost are aligned.
You do not want your stabilizer to
be tilted to one side or the other.
- While carefully
maintaining this alignment, use the
3/16" holes in the sides of the
keel extension as guides and drill
3/16" holes through each side
of the keel. Make a final pass
with the drill all the way through
the keel, and verify that the 3/16"
clevis pin can be easily installed.
- Insert the clevis
pin and secure it with the safety
For breakdown and storage
remove the stabilizer cover, remove the stabilizer
frame and separate the tubes, then roll the
frame and cover together and stow in the glider
- Join the trailing
and leading edges of the stabilizer
frame by inserting the corner fitting
on the straight trailing edge tube
into the end of the leading edge tube.
The stop-collared ends go at the bottom.
- Insert the frame ends
into the bushings on the keel extension
with the curved leading edge tube
forward. Make sure the stop-collars
seat against the bushings.
- Slide the dacron stabilizer
cover over the frame and secure with
the overlapping velcro. The cover
should be pulled on as tightly as
possible. Installing the cover
can be easier with the glider set
up and the extension tube on the glider.
Tuning your glider after installation:
The stabilizer weighs a little more than one
pound, and even after shortening the keel,
will add enough weight to the rear of the
glider to change the trim. Depending
on your weight and glider model, you will
need to move your hang loop forward 3/8"
to 1" to recover your original trim speed.
Please contact your
dealer or Wills Wing if you have any questions.
17 October, 2003