20
Faults do not cure themselves!
This test can only be carried out if the wireless band is undisturbed and no further
remote control transmitters are being operated, even on other channels! Such trials
are not advisable on high mountains due to the extremely strong field strengths and
overshoots by other transmitters. If you are unsure about anything do not under any
circumstance fly your model, even if you are very keen to try it out and the spectators
demand a first flight demonstration.
The First Start
The first flight can be carried out in different ways: at a slope site from a hand launch,
at a flat-field site or via an aero-tow.
Aerotow
is the best (safest) method to launch your Alpina 3001 for the first time. Do
not forget the usual arrangements between you and your tug pilot!
At a slope site:
Wait for a good upwind phase and throw the model diagonally
downwards. Let the model initially flop – gaining speed is half the battle! If necessary
adjust the trims to achieve straight and level flight and maintain speed. Then fly
control switch curves to test cornering characteristics, control throws (roll, pitch and
yaw). Be sure to extend the air breaks/flaps briefly at height to get to know the
behaviour of the model.
If there is sufficient height, check the centre of gravity at the same time. The
procedure for checking the centre of gravity described in the following is a fine-tuning
of the centre of gravity. This method requires gentle airflow and a precisely balanced
centre of gravity; it fails in strong winds or when severe balancing errors are made.
During strong winds it is very difficult to trim the normal speed as it is very hard to
estimate the actual speed in relation to the ambient air.
The model is being trimmed in normal speed; this is considerably higher than the
pitch speed. The model must not undulate or appear "spongy" and heavy to control.
The flaps are on "neutral".
Now – provided the model is flying at a safe height – briefly apply down elevator to
place the model in a steep dive. Then allow the elevator to return to neutral
immediately and observe the flight path. The centre of gravity can be considered to
be about right if the model recovers in a gentle upward arc (100 m) without any
further control inputs.
The centre of gravity is too far forward if the model bounces quickly out of the dive
and climbs steeply.
Action:
Remove lead ballast from fuselage nose, trim depth a little.
The centre of gravity is too far back if the model shows no tendency to recover, or
indeed if it even begins a steeper nosedive.
Action:
Intercept the model immediately. Add lead to the fuselage nose and secure,
trim height a little.
