23
A NOTE ABOUT CABLES AND CABLE MAINTENANCE
The cables which support the glider’s airframe are critical components of the glider’s structure, and must be
maintained in an air worthy condition. It is a general practice in the design of aircraft structures to design to an
ultimate strength of 1.5 times the highest expected load in normal service.
Hang glider cables, like other structural components on the glider, are typically designed with a structural safety factor
of only about 50% above the expected maximum load. No significant loss in cable strength can be tolerated.
A cable with even a single broken strand must be replaced before the glider is flown again. A cable which has been
bent sharply enough to have taken a permanent set must also be replaced immediately.
Some degree of fatigue due to repeated bending of cables is almost unavoidable in an aircraft that is assembled and
disassembled with every flight. Side wires are subject to the highest loads in flight, and are therefore the most
critical. This is why we recommend that these wires be replaced annually, even if there is no known damage.
SIDE WIRES REPLACEMENT
Figure 36
To replace the side wire:
1. Unbolt the leading edge/cross bar junction and
disconnect the side wire from the leading edge/cross
bar junction.
2. To disconnect the side wire from the control frame
lower fitting you will need a sleeve extractor, supplied
with the glider and a hammer. Knocking on the
sleeve extractor from rear to front, move the sleeve
out as much as necessary to remove the wire (Fig.
36).
3. To install the side wire simply reverse the
procedure written above.
GLIDER TUNING
TRIMMING YOUR GLIDER IN PITCH
CG ADJUSTMENT
You will find that the pitch trim of the Combat-C, as well as the basetube position at trim, changes with VG setting. At
VG loose, the Combat-C will normally be trimmed very close to stall. The bar position at trim at VG loose will be
relatively far out. As you set the VG tighter, the trim speed will normally increase and the trim bar position will move
back.
At VG loose, the pitch is very well defined, and the pitch force increases quickly as you pull in from trim speed. At
tighter VG settings, the "pitch well" becomes more "shallow," and the pitch force increases much less as you pull in
from trim speed.
Overall pitch trim is affected by several factors. Among the most significant is the location along the keel of your hang
point. The farther forward your hang point is, the faster the glider will trim, the less effort will be required to fly fast,
and the more effort will be required to fly slow. If the glider's trim is too slow, it will make the glider more difficult to
control in roll, especially in turbulent air and when the nose pitches up on entering a strong thermal.
On the Combat-C, hang loop fore and aft position is adjusted by repositioning the hang point tower on the keel.
Do
not miss the holes in the keel tube during hang point position adjustment!
Pilot’s weight has an effect on the trim speed. If the trim speed is got for a pilot of 80 Kg, a pilot of 60 Kg has to move
the hang point tower to the next backward hole to keep this trim speed.
COMBAT-C SPROG ADJUSTMENT AND FLIGHT TESTING
The Combat-C uses inboard and outboard sprogs in combination with one transverse batten on each sprog. Each
transverse batten spans two top surface battens, so a total of eight top surface battens are supported. The sprog
system is the primary component of the system, which provides pitch stability.
Содержание COMBAT-C
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