25
3. Replace bottom side wires and hang loops.
SPECIAL CIRCUMSTANCES
1. Any time you suffer a crash or extremely hard landing you should have an “annual” inspection done on
your glider to insure that you find all damaged parts. Following any hard landing be sure to inspect the
apex hardware, the control frame legs and speed bar, and all control frame fittings for damage. Any time
you replace a downtube or speed bar, you must carefully inspect all related fittings and replace any that
are bent or damaged.
Hard landings may also impose very high loads on the sprogs and bridle lines. Inspect them accordingly.
2. If your glider is ever exposed to salt water you will need to have the glider completely disassembled in
accordance with the recommended annual inspection procedure. All frame parts will need to be
disassembled, including the removal of all sleeves and bushings, flushed liberally with fresh water, dried
completely.
3. A wet glider must be dried before storing. Do not leave your glider wet for more than one day, because
corrosion may result.
4. Take special care to avoid ice-covering the glider, particularly the leading edge in wintertime.
5. If you fly regularly at the coast in windy conditions, be aware that the sea mist spray can have the
same effect. Hose down your glider after such flights, and keep a special lookout for corrosion.
6. Keeping your sail clean will extend the life of the cloth. When cleaning the entire sail you should
generally use only water and a soft brush. You may clean small spots or stains with any commercial spot
remover that is labeled for use on polyester.
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 airworthy 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. Bottom 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.
CHECKING THE SAIL WASHOUT
1. Fully set up the glider on a reasonably level surface.
2. Place three equal supports, about 1,7 m (5.5 ft) tall, under the each leading edge tube-cross tube
junction and in place behind the connection of rear bottom cables to a keel tube.
3. Tie a lightweight string tightly across the wing from the inner of the supported battens to the
corresponding batten on the other wing.
4. Measure the height of each thread relative to the top of the keel tube. The results should be as follows:
Fox-16
Batten number Sail height above keel tube, mm
1 - 1
258
2 - 2
375
3 - 3
359
6 -6
335
