TECHNICAL BULLETIN
Wills Wing Inc 500 West Blueridge Ave Orange, CA 92865 Ph/Fax (714) 998-6359/0647
Hang Loop / CG Adjustment
Reflex slows the glider trim speed approximately three mph. Mark the location of the rear of the hangloop on the keel. Adjust the
hang loop 1/2 inch forward. Check that the forward hang loop adjustment tang is pinched firmly against the keel so loop can not
shift position.
Flight Test Verification
A flight test verification is essential for proper adjustment of the bridle system. The shadow of the bridle cables can be seen on
the sail when flying in direct sun exposure. Perform a shallow circling turn away from obstacles or traffic. When the shadows of the
cables are visible on the sail, lightly shake the control bar basetube. The degree of movement will indicate the amount of slackness
in the cable. At VG loose, the slackness should progress from
just slack
to
slack,
inboard to outboard. VG tight, the progression
should be from
snug
to
just slack
(slightly tighter than VG loose). Please refer to your
Owner/Service Manual
under the section
Test Flight and Checking The Bridles
for definition of the terms
slack
and
snug
.
If the outboard bridles become tight before VG tight, pitch bar pressure at high speeds will be higher VG tight than VG loose,
and handling in rough air will be adversely affected. If the bridles are looser than specified, optimum stability will not be achieved.
A final evaluation of the bridle adjustment should be made by flying the glider in a steady state, pilot full forward dive at each of
three settings from VG loose to tight and checking the pitch bar pressures.
This should only be done in smooth air
. The pilot full
forward position should be approached slowly and gradually so that zooming and hysteresis in speed are avoided. At steady state
pilot full forward, the pitch pressure should fall in the range indicated on the graph below. As a reference, the VG loose pitch
pressure on a RamAir is approximately 1/2 to 2/3 of an HP AT. The pitch pressure will decrease slightly and progressively as VG
engagement is increased, as indicated on the graph.
Please note that new RamAir 154 bridle system does not induce reflex in the inboard sail at VG tight position as it did with the
original bridle set.
Modification Verification Card
Please complete and return the attached
Modification Verification Card
promptly. This information will provide the basis for
tracking the progress of the upgrade and providing you with supplemental information or instructions if necessary.
Glider Owner's Manual
Please staple this Technical Bulletin into the rear of your
RamAir Owner's Manual
for future reference.
In Closing
We apologize for any inconvenience and frustration this action has caused to our valued customers. Please feel free to contact
Wills Wing if you have any questions.
Bulletin #: TB940501 RamAir Pitch Stability Modification
Date: 5/25/94
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