Hobbico NexSTAR EP Instruction Manual page 17

To know if the sun is above 25 degrees in the horizon, place
the fuselage roughly 90 degrees to the sun and then look at the
shadow of the wing on the main landing gear. If the main landing
gear is completely inside the wing's shadow, then it is safe to fl y
with the PA-2 module adjusted to the desired gain. If any sun hits
the main landing gear, then it is best to set the gain of the PA-2 to
zero or to disconnect it. Flying with the PA-2 module active under
this condition may produce less than desired results.
The PA-2 is not an autopilot. It will not fl y the airplane for
you. What it will do is return the airplane from virtually any
attitude to straight-and-level when the sticks are released
(provided there is enough altitude to recover). The gain
determines how fast it stabilizes your airplane. To adjust the
gain, rotate the screw adjustment in the PA-2 module fully
counterclockwise (zero gain) and then rotate clockwise to the
position you desire. After extensive testing, we have found
that the optimum gain for inexperienced pilots is around
35% of the total gain. As you progress in your fl ying skills,
gradually decrease the gain on the unit until you effectively
turn it off by setting it to zero gain (fully counterclockwise).
Experienced pilots may feel fl ying an airplane with PA-2 a
bit awkward. The reason is that experienced pilots usually
fl y airplanes with neutral stability (or close to neutral). During
fl ight they bank or pitch their airplanes to different attitudes and
then they release stick pressure for the airplane to remain in
the attitude they put it into. Your NexSTAR EP Select with PA-2
wants to fl y straight and level so in order to keep the airplane
in a bank or in a pitch attitude, the stick needs to be held in a
given position. Otherwise, the NexSTAR EP Select will try to
go back to level. As the gain is decreased, this feeling will also
decrease. Because of this, it is recommended that your fl ight
instructor reads this section of the manual. Also, note that the
PA-2 module offers stick-operation priority. That is, when the
sticks are operated, the PA-2 sensitivity decreases accordingly
as they have priority in controlling your airplane's servos. The
sticks always have control priority.
Because of the constant corrections the PA-2 tries to make,
the receiver batteries will discharge faster than in an airplane
without PA-2. It is important to check your battery's voltage
before every fl ight and to recharge them if necessary. As a
rule of thumb and after many hours of testing our prototypes
were never fl own with a receiver battery voltage less than
5.0V. Some radio manufacturers recommend a cut off voltage
of 4.8V, but remember that the PA-2 is making your servos
draw current from your battery much more often than on a
regular radio system. It is always better to play it safe and
recharge. Use a Hobbico Digital Voltmeter MKIII (HCAP0356)
to check the battery voltage before every fl ight.
After connecting the PA-2 sensor to its module and setting its
gain, the PA-2 will be ready for a short test. This test is to ensure
that the unit is making corrections in the adequate direction. It is
very important that you perform this test before your fi rst fl ight
and after modifying any setting in the PA-2 module. There are two
ways of performing this test. Perform the one you prefer:
Indoor Test: For this test you will need a fl ashlight.
❏
1. Turn on the transmitter and then the receiver. Make
sure that the PA-2 Pilot Assist Link is "ON" by activating the
2-position switch on the transmitter face labeled "Ch.5 Gear."
❏
2. Point the fl ashlight beam toward the front of the PA-2
sensor. The elevator should move down.
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