separate the various cables associated with the turbine and the turbine electronics from the cables associated with
the receiving system, i.e. servo extension leads and the like. The cable looms can be secured in the model using
self-adhesive cable tie fixing pads.
In our models we linked the two rudder servos to a single receiver output by means of a Y-lead. The nosewheel
steering servo is also linked to the same output using a second Y-lead.
When you are setting up the retract units and the steerable nosewheel please note that A) the nosewheel must be
exactly “dead-ahead” at the centre position, and B) the steering cables must not get tangled when the gear is
retracted (Fig. 21). The parts required to steer the nosewheel are not included in the kit.
The pressure tank for the pneumatic retractable undercarriage, and the turbine gas tank, are installed forward of
the nosewheel former (plenty of foam padding is sufficient). As can be seen in Fig. 21, we fitted the turbine gas
tank standing upright, secured to the noseleg former with a cable tie. For this arrangement you will have to drill
your own holes.
If you have built the model exactly as we have described, and installed the recommended airborne RC
components and turbine system (JetCat P 80 / P 120), then the Centre of Gravity should be more or less correct
without requiring much ballast. Check the CG with the tank empty and the canopy in place.
The Centre of Gravity of the model should be located about 95 - 100 mm forward of the front edge of the
wing joiner tube.
The next step is to program the radio control system; we recommend the following control surface travels as a
starting point:
Elevator travel
+/- 25 mm
)
Aileron travel
+/- 20 mm
)
20% Exponential
Rudder travel
+/- 8 - 10 mm
)
Both control surfaces on each wing panel should deflect by exactly the same amount up and down.
The two surfaces on each wing panel work in parallel, operating as mixed elevators and ailerons (elevons).
A typical programming procedure for the mc-24 radio control system is included in the building
instructions.
When programming the system and setting up the control surfaces it is important to ensure that the
travels are completely symmetrical and synchronous, i.e. if you apply up- or down-elevator, all four
elevons should move an equal distance up or down. This ensures that the model will actually climb
straight ahead when you apply up-elevator, rather than flying a roll!
Calibrating the elevon travels is very important to the model’s control response and general flying
characteristics, and we strongly recommend that you measure the deflections carefully using geometry
measuring instruments (setsquare etc.) while you are in the peace and quiet of your workshop - not at the
flying field.
The model’s appearance is improved considerably by picking out the canopy in a contrasting colour, masking it
out along the moulded-in lines. Apply the decals supplied in the kit to finish the model off nicely.
Before you test-fly the model, check that all control surface linkages are really slop-free, and secure all locknuts
with a drop of Thread-locker fluid. Check that the retract system works with 100% reliability, that all three legs
lock when extended, and that the turbine and its associated system components are in order.
Check that you have programmed all the control surfaces to deflect in the correct “sense” (direction), and that the
travels are as stated.
Carry out a comprehensive range check with the turbine running.
Are all the installed components properly mounted and adequately secured? Could they tear loose,
