User Manual ATOS C
Version: 29.01.2002 English
translation: 9 August 2002 by Heiner Biesel
Please read before flying!
Congratulations on your purchase, and welcome to the
ATOS world! Your ATOS C is a high performance glider. To fully exploit its
capabilities while remaining well within safe limits, you should become
thoroughly familiar with the contents of this manual. If you have any questions
or need support, do not hesitate to contact the A.I.R. Team.
Your A.I.R. Team
·
By car
The
carbon fiber D-tube can be damaged by point loading. For safe transport the
glider should always be supported by a large padded area. A ladder with several
padded steps is one possibility. If the D-tube is supported at only two places,
these supports need to be padded at least 4 inches in length, and wide enough to
support the full width of the glider. Anything less is likely to result in
transport damage, which can seriously reduce the strength of the main spar and
the entire D-tube.
Do not
tie down the glider too tightly, and use wide tubular of flat webbing to
minimize point loading. If the glider is likely to get exposed to rain, and
especially to salt water, a watertight cover bag is strongly recommended. If the
ATOS C gets wet, dry it as quickly as possible to avoid staining the sail, or
causing corrosion of the metal parts. Exposure to salt water should always be
followed by a thorough rinse in sweet water. The carbon fiber parts do absorb a
small amount of moisture, and should be dried as soon as possible.
·
By ski lift or cable car
The same
considerations apply, except that additional padding is usually required. A.I.R.
sells a watertight cover bag, which includes padded supports which can be
velcroed to the cover bag at the required points. During flight they can be
stowed inside the D-tubes of the glider.
1.)
Avoid laying the D-tubes on
rocks or uneven ground. If this cannot be avoided, consider placing the nose on
something soft, like a harness, or some padding. Remove the base bar from the
D-tube where it is stored.
2.)
Connect the downtubes to
the base bar. Careful, don‘t drop one of the downtubes; doing so can damage
the D-tube or one of the ribs.
3.)
Put the ATOS on the control
bar, making sure it is stable. If it should fall over, the D-tube or the
fittings that attach the downtubes to the keel can be damaged.
ATOS standard control bar
4.)
Remove all parts stowed
inside the D-tubes. Place the tip extensions and tip wands close to the tips of
the wing.
5.)
Open
up the two halves of the nose lever as shown.
The
wing can be damaged if this is not done before
the
wings are spread.
6.)
Spread the wings far enough
apart for the keel to touch the ground.
7.)
Hook the sail to the keel
using the rings at the trailing edge. The keel can be moved a little from side
to side to make this easier. Avoid large displacements as these could damage the
flaps. The flaps must be behind the downtubes before the sail can be connected
to the keel.
8.)
Close the top zipper.
9.)
Tighten the nose lever and
safety the pip-pin. Use the nose tube as a lever, if necessary. Make sure the
wingtips are as far forward as possible, otherwise excessive force may be
necessary on the nose lever. Hook up the front cables.
10.)
Insert nose tube until the
catch engages the hole in the keel.
11.)
Insert the keel stinger.
12.)
Insert the tip extensions
until they are fully seated. This is best done by opening the velcro between the
last two ribs and folding the sail back to fully expose the end of the D-tube.
The D-tube and the sail can be damaged if the tip-extensions are not completely
inserted. Place the carbon inserts on the velcro of the tip extensions, edge
even with rib 9.
13.)
Open the velcro at the tip
of the sail and insert the tip wand all the way into the hole of the tip
extension. The slot at the end of the tip wand should be roughly parallel with
the trailing edge of the sail.
14.)
Tighten the tip wand.
15.)
Tighten the ribs starting
from the end of the wing. After tightening rib 6 you should attach the spoileron
lever to the spoileron surface by means of the provided bungee loop. The ribs
are tightened by fully inserting the metal fitting on each rib, and only then turning them with thumb and finger of one hand. Do
not push or pull on the rib with your other hand, this runs the risk of damaging
the rib. If the sail is tight and you cannot exert enough force on the rib
fitting, you can use your other hand to push only on the very end of the rib.
Gloves help! An optional tool is
available which greatly reduces the effort required to tighten the ribs. Be
careful when using this tool, it is possible to exert too much force and to
break ribs. The tension at each rib can be adjusted by moving the velcro
attachment of the rib fittings. It is recommended to adjust the tension after
about 10 hours of flight, or whenever there are great changes in climate. Rib
number 6, the spoiler rib, is especially critical in this regard. Ribs 7 and 8
should be as tight as practical so that the sail will remain clean smooth at
high speeds.
The
picture to the right shows the use of the
optional
tool for tightening the ribs.
16.)
Attach
the spoileron to the actuating lever.
17.)
Attach the flap control
cable via the pins to the rear of the flaps.
18.)
Attach the control cables.
Make sure that rib 6 is fully tightened at this point, otherwise the sail or the
D-tube could be damaged.
19.)
Pull the flap cable through
the catch on the base bar.
20.)
Close the lower zipper.
21.)
Attach nose fairing, making
sure it makes a clean connection with the velcro.
1.)
Disconnect the spoileron
cables.
2.)
Disconnect the flap cables.
3.)
Loosen the ribs, starting
with the innermost ribs. Rib 8 must be folded inward toward the keel, unlike all
the other ribs. In order to do that, rib 7 has to be turned toward the keel far
enough for rib 8 to clear it. Once rib 8 has been folded inward, rib 7 can be
folded outward.
4.)
Remove the tip wands and
tip extensions.
5.)
Fold the sail around the
D-tube from the front. Stow the tip lever inside the sail. Slide tip cover bag
over the sail.
6.)
Pull out the stinger.
7.)
Remove the nose cover and
carefully loosen the nose lever. Make sure the stinger has been removed,
otherwise the flaps could be damaged.
8.)
Open top and bottom
zippers, and place the zipper pulls at the trailing edge of the sail. If the
pulls are left at the front they can be damaged when the glider is folded up.
9.)
Fold the top zipper back
toward the wing tips to avoid crushing it between D-tube and keel.
10.)
Attach padding for
downtubes on the controlbar-keel junction.
11.)
Fold the D-tubes toward the
keel. Make sure that the control cables have been detached. If they are not, the
D-tube and the sail can be damaged.
12.)
Stow the tip extensions,
tip wands, stinger, and nose tube in the D-tube.
13.)
Place the cover bag over
the glider, starting from the nose.
14.)
Turn over the glider and
place carefully on the ground. This is best done by lifting the D-tubes with one
hand while rotating the glider with one of the down-tubes.
15.)
Slide the base bar into the
left D-tube.
16.)
Place flaps and spoilerons
flat on top of the D-tubes, white (top) side against white side. Make sure that
the spoilerons do not extend beyond the sides of the D-tubes.
17.)
Place the nose cover on the
flaps. The carbon inserts can be placed over the outside of the D-tubes in the
tip area. Make sure that the profile of the inserts matches that of the D-tube.
Zip up the cover bag.
The
ATOS C is statically slightly tailheavy. After a few steps it will stabilize in
a neutral attitude. During the first few
steps it is important, however, to keep the nose low. Generally it is better to
keep the nose lower than optimal. This makes the glider less sensitive to side
gusts and keeps the wingtips further off the ground.
It‘s a good idea
to do some running on flat ground to get a feel for the behavior of the wing
prior to the first flight. The highly effective spoilerons make it possible to
keep the wing stable and steady even during gusty launch conditions.
For
normal starts the flaps should be deflected about 15°. Launch technique is
similar to that for high performance flexwings.
The
ATOS C is controlled purely via weight shift. Pitch control is exactly the same
as on any flexwing, while roll is controlled via spoilerons, which are actuated
through a horizontal shift of the pilot‘s body. The forces needed to control
the ATOS are considerably less than what a normal flexwing The glider is quite
stable in all three axes and requires little high-siding in turns. Unlike a
flexwing, the ATOS does not react to short control impulses. A properly flown
turn requires a slight pull-in on the control bar, since the spoilerons create a
small amount of pitch-up when they are actuated. It is possible to lose a
significant amount of airspeed if one flies a series of roll reversals without
paying attention to airspeed.
Spoileron
actuation of 50% or more creates a strong yaw moment, which can be advantageous
when entering a thermal, for example. Higher speeds can cause excessive yawing
which can lead to PIO yaw oscillations in turbulent air. Such oscillations
dampen out quickly if the pilot avoids any roll input to the glider.
Above 40 mph and
with flaps at 70°, or above 45 mph with flaps at 0° to 15°, pilots should use
reduced control inputs. These speeds are reached when the base bar is roughly
even with the stomach.
In order to verify that the trim speed is correct, and
that the glider does not exceed Vne an airspeed indicator should be carried on the glider.
Do not attempt to
spin the ATOS C! Spins can cause the glider to exceed its design load limits!
Spin Prevention:
Incipient stalls can be
stopped by centering and pulling in slightly on the control bar. Depending upon
the hang-point position and the height of the pilot, a stall can begin when the
base bar is pushed ahead of the head of the pilot. While thermaling in smooth
air the base bar will normally be between the eyes and the nose of the pilot.
For
normal thermaling 15° of flaps is optimal. Larger thermals or broken lift often
require flatter turns and less flaps. In turbulent air 5° of flaps works best,
since this permits higher speeds.
Above
40 mph the best L/D glide is achieved with a flap setting of 5°. With this flap
setting the glider reaches its best L/D at around 33 mph, and even at 40 mph the
L/D has not deteriorated significantly. In light sink one should not fly any
slower than 40 mph.
The flaps should be fully deflected prior to landing,
since the glider has the lowest stalling speed at this setting. The glidepath
can best be controlled by varying airspeed, rather than flap setting. For first
landings we recommend pulling full flaps at 150 feet and flying a long final
leg. The flare window is comparatively large. Best landings are achieved by a
strong flare late in the landing phase.
Typical mistakes: Flying the final leg too
fast combined with roll inputs, which creates strong yaw movements. Flap
adjustment during the landing phase without paying attention to the actual
landing point. Getting too slow when going upright on the downtubes. The hands
should be no higher than the midpoint of the downtubes, so that it is still
possible to pull in on the control bar to increase airspeed if needed.
Tip: To keep the flap control cable from coming loose,
throw it over the front of the base bar. This keeps it out of the way, and even
an accidental pull on it will not pull it out of the cleat.
A flap setting of
15° is optimal and permits good speed control. In addition, the glider will
reach its maximal towing altitude at this setting. It is essential to maintain
adequate airspeed by keeping the base bar roughly even with the head of the
pilot. Flying slower results in less altitude gain, and less speed reserve. A
stall on a winch tow is a very dangerous event and requires quick and correct
action!
15° flaps are
optimal with no head wind. With increasing headwinds, lower flap settings are
indicated (5°). The ATOS will be more stable at lower flap settings, and the
trim-speed of the glider is higher. Important:
Avoid flying below the towing aircraft! The downwash from the towplane can cause
a very strong pitchdown moment. This is especially true for trikes.
The ATOS C lands
easily even with the flaps undeployed. This is especially useful if one
experiences a weak link break at low altitudes. Concentrate on airspeed and
glidepath, and don‘t worry about the flaps if you experience a line break
shortly after launch.
·
Adjusting trim speed
Optimal trim speed lies somewhere between minimum sink
speed and best L/D speed. The glider should trim to approximately 30 mph with
the flaps fully retracted. Slower trim speeds mean that the glider could be
easily stalled by pushing out minimally on the control bar. For initial flights
we recommend a higher than normal trim speed.
The glider will trim about 3 mph faster if the cover
bag is stowed in the D-tube during flight, which corresponds to moving the
hangpoint forward about ½ inch.
Trim speed can be adjusted by moving the hangpoint. It
is best to move the hangpoint no more than ½ inch at a time. If the velcro no
longer holds securely, it is very important to replace both the hangloop and the
velcro on the keel. Otherwise, trim speed and handling could change in flight.
The
composite materials used in the construction of the ATOS C wear and break quite
differently from conventional metals. Aluminum and steel are ductile and show
characteristic deformations when they are damaged or overstressed, although
metal fatigue due to repeated loads beyond the elastic limits of the metal can
create very small cracks that are very difficult to detect.
Composite
materials generally do not deform if they are overstressed. Other means of
determining damage include visual inspections at points of high load
concentration, signs of delamination, or testing the stiffness of a component by
applying a load to it. These methods of inspecting composite structures require
some skill and experience. For this reason we recommend an inspection by an ATOS
dealer if there is any possibility of damage to critical components.
A
dealer inspection is required every 200 hours, or two years, whichever comes
first. The following maintenance items should be completed by the owner. In case
of questions, please contact a dealer or the manufacturer.
The
factory adjusts the control cables to have about ½ inch of play to either side
before the spoilerons are actuated. This should be checked before every flight
by lifting the nose and moving the control from side to side.
During
the first few hours of flight there is some stretching of the cables. This does
not affect the safety of the glider, but if there is more than an inch of slack
the cables should be adjusted. This can be done via the adjustment screw on each
of the spoiler levers.
Whenever
the spoiler cables are adjusted it is essential
that the stop cable be adjusted as well.
To avoid damage to
the spoileron rib and lever, the spoileron cable has a stop. This consists of a
cable between the spoileron cable and the keel, which limits the travel of the
spoileron cable.
·
Adjustment of the stop
cable
The
spoileron cable must be able to produce a full 80° of spoileron deflection. At
this deflection the stop cable should be taut. If the stop cable is too short it
will not be possible to achieve the full spoileron deflection, reducing roll
control authority.
Adjust
the length of the stop cable to provide about 80° spoileron deflection, and
check before every flight.
Spoileron cables must be replaced every 200 hours, or
every two years, or whenever they show any visual wear or damage. The spoileron
steel cables which connect to the control frame, and which double as front
control bar cables, must be replaced every 100 hours, and should be checked for
wear and function prior to every flight.
All
pulleys should be checked for wear and damage. They should turn freely, and
without play or noise. Check all of them at least every 50 hours.
Ribs can be checked visually, and by touch. Squeezing
the rib can show weak or damaged areas, either through a characteristic
crackling sound, or via a deflection of the material.
The connections between the ribs and the D-tube should
be checked especially carefully by pushing the end of the rib up and down a bit.
Again, sound and deflection can indicate some damage.
Rib 6 also holds the spoileron lever, and should be
checked especially thoroughly. Look for any damage to the lever or its
attachment to the rib.
Check the outer
ribs and the tip wand if they have contacted the ground during a landing.
The bolts which attach the downtubes to the keel should
be checked and lubricated ever 50 hours or 20 flights.
·
D-tubes
The
D-tubes can be easily damaged through point loading, either during transport, or
if they are placed on rocky ground. Damage to the leading edge nose section of
the D-tube can be detected by running your hands over the D-tube and feeling for
dimples, dings, soft spots, or depressions. Minor damage in this area can often
be repaired by epoxying a carbon fabric patch over the spot after filling the
area with an epoxy-microballoon mixture. Contact your dealer for help.
However,
damage to the D-tube in the area of the spar, or anywhere along the innermost 5
feet of the D-tube, may require a complete replacement of the affected D-tube.
Only a dealer or the factory can determine if the D-tube can be safely repaired
in these areas, or whether a replacement D-tube will be required. Crashes which
cause major damage to the keel, or transport which may have created heavy point
loads to the D-tube, also require an inspection by a dealer, even if there is no
immediately apparent damage to the D-tubes.
If the
sail has gotten loose the cord at the tip wand can be tightened, as can the rib
tighteners. Adjustments may be necessary after the first few hours of flight.
Damaged cables, cords, or webbing should be replaced as soon as it is detected.
Pay special attention to rib number 6, which holds the spoileron lever, and to
the tip wand cords.
·
Sail webbing
It is
essential that the webbing, which attaches the rear of the sail to the keel, be
taut when the wing is fully set up. Loose webbing means that the wing will not
have the correct sweep, and the CG will be off, both of which will affect flying
characteristics and safety.
Wing
sweep should be checked every ten flights, or whenever temperature and humidity
could affect the sail. To check the sweep of the wing, attach a thin cord or
string to the rib tighteners of the outermost ribs. This string should cross the
keel at the hole, but in no case more than ½ inch ahead or 1 inch behind this
hole, when the keel is held horizontally. If this is not the case, adjust the
webbing at the keel to produce the correct wing sweep.
Check the flap
cord every ten hours. The attachment points between the lines and flaps are
especially vulnerable to wear and damage, and should be checked often.
Replace
the flap bungee if it has weakened to the point where the flap will not fully
retract when there is no tension on the flap cord.
It is
possible, however, that the bungee is strong enough, but the velcro attachment
between flap and the lower sail is too tight. Loosening this attachment and
moving the flap further back can correct this problem. It also possible to
tighten the bungee at the point where it attaches at the front end of the keel.
After
extended use, all seams, straps, and attachments of the sail should be visually
inspected. The zippers should move freely. Storage in a dry, cool place, and
minimal UV-exposure increase the life of the sail. If necessary, tighten the
webbing which attach the sail to the keel.
Vne with 0 - 15° flaps
50 mph
Vne with 70° flaps
50 mph
Maximum positive load
+4g
Takeoff weight range
90-152 kg
Span:
42 feet
Aspect ratio:
12.1
Flap range:
0 - 70°
Wing area:
146 ft2
Weight:
77 lbs.
(Weight is approximate due to the use of composite
materials)
We are happy to answer your questions and appreciate tips and suggestions
about our products. Additional information can be found on our website
http://www.a-i-r.de/
The A-I-R team hopes you will enjoy many pleasant and safe flights on
your ATOS.