25
To adjust the main sprog height:
1. Fully unzip the access zipper to gain access to the crossbar-LE junction (Fig.40).
2. Remove the pin from the sprog threaded adjuster at the front of the sprog. Remove the sprog rope pin from the
crossbar. Remove the sprog from the sprog threaded adjuster. Untighten the sprog locking nut inside the sprog
threaded adjuster. Install the sprog on the sprog threaded adjuster and install the sprog rope back on the crossbar.
3. To raise the sprog, turn the end of the sprog threaded adjuster counter clockwise. To lower the sprog, turn it
clockwise.
4. Re-install the pin on the sprog threaded adjuster, zip the access zipper and press down firmly on the rear end of
the sprog to seat the cable before checking the measurement again.
TEST FLIGHT
If the sprogs are set too low, it may cause a significant increase in trim speed and a reduction in pitch pressures at
tighter VG settings, and there will be a reduction in pitch stability at angles of attack below normal flight. This stability
reduction could increase the probability of a turbulence-induced tumble or other in-flight stability related loss of
control. If the sprogs are set too high, it may cause excessive pitch bar pressure at high speeds, and excessive roll
control pressures, lag in roll response.
Please be aware that flight-testing encompasses a very limited angle of attack range and that there is no correlation
between pitch stability in the flight test envelope and pitch stability in the extended angle of attack range that is
investigated on a test vehicle.
This test is best performed by a qualified test pilot, and, in any case, should be performed only in smooth air and with
caution.
TURN CORRECTION
Turns are caused by an asymmetry in the glider. If you have a turn, first try to make the glider symmetrical in
every way. If a turn appears only at VG settings of 3/4 to full tight, it may be an indication that the sprogs are set
asymmetrically.
In this case you have to lower the sprogs on the side the glider is turning towards and raise the sprogs on the other
side by the same amount.
To lower the sprog, turn it clockwise. To raise the sprog, turn the sprog counter clockwise. One full turn raises or
lowers the sprog about 15 mm (see the section above
METHOD OF SPROG ADJUSTMENT)
.
Turn correction with VG off can be implemented in two ways:
- rotating one or both sail mount plugs;
- removing the outer leading edge tube shims.
Figure 41
A left turn correction with the sail mount plugs:
- twist the right sail mount plug clockwise twisting the sail
up at the right trailing edge;
- twist the left sail mount plug clockwise twisting the sail
down at the left trailing edge;
- twist both sail mount plugs clockwise.
We recommend for the left turn correction to start with
twisting the right sail mount plug clockwise one or two
notches. If this does not help - go and twist the left sail
mount plug clockwise (Fig. 41).
NOTE
Do not twist plugs more than two notches - the
adjustment gets ineffective after this point.
After you set the
sail mount plug in the desired position
hold it strongly until the fixing screw is tighten so that the sail
mount plug is not rotating any more.
Each outer leading edge tube may have one 2 mm and one 3mm shim installed between the end of the leading edge
tube and the sail mount plug.
Another possibility of turn adjustment with VG off is removing the outer leading edge tube shims.
Summary of Contents for COMBAT-C
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