Electronics needed

Servos to be used for Vtail donít need much power, but they have to be precise.

Personnally,I use graupner C271, 12g servos with ball bearing.

If you only use 15mm servos, more powerful and solid in case of hard landings , you can still make internal linkage on flaps, but it will have to be external on ailerons.

If you want internal linkage on ailerons, you have to use servos of a maximum width of 13mm, and locally reinforce the wing with an aluminium tube (as shown on the web page).


Servo locations are outlined on the underside of the wing, be aware that it is necessary not to change these places as local reinforcements are done; a little mark shows the location of each control horn on the ailerons and flaps (microballoons reinforcement) .

Maximal size for battery is 5 cells of 43/17mm, 2 in the front and 3 at the back.

Receiver needs to perform well and being not too big, asSchulze alpha8w, antenna must be lengthened and extend out of the fuse tail by at least 50cm to overcome carbon interferences.


1.    Center of gravity

CG is at 83 mm from the leading edge. With a big battery (as described) it needs about 50 to 100 g of lead in the nose. For the first flight it is best to put 25g more in the nose to start safe setups.


2.    Control set up

Positive (+) values refer to down movement of the control surfaces and are measured at the root.


Vtail setup :

elevator :†††††††††††††††††††††††††††† +9††††††††† -9

Rudder :†††††††††††††††††††††††††††††† +7††††††††† -7

Flaps compensation :†††††††† +1 †††††††† (elevator 1mm down when the flaps are down)

Airbrakes compensation :+3 †††††††† (elevator 3mm down with maximum airbrakes)


Ailerons setup :

Aileron function : ††††††††††††† +20††††††† -28†††††††† (when flaps are used the aileron differential is increased)

Elevator function:††††††††††††† +7††††††††† -7†††††††††† (when the elevator is fully up the ailerons are lowered by 7 mm)

Airbrakes function:††††††††††† †††††††††††††† -28

Flaps(using as ailerons) :†† +15††††††† -15††††††††


When airbrakes are maximum, to keep control, ailerons must still be reactive, total range of ailerons is 35mm up


Flaps setup :

Aileron function :†††††††††††††† +12††††††† -18

Elevator function :†††††††††††† +10††††††† -10

Airbrakes function :†††††††††† +30

Flap fonction(4axes) :†††††† +18††††††† -18


When airbrakes are maximum, flaps donít move with the aileron stick (so maximal range of flap is 30mm down).

3.    Race setup


Use of flaps :

Constant use offlaps is not recommended during the race (only snap flap).

Flaps are only used during climbing, maximum value in light to medium wind (3 to 15m/s) (+18 flaps, +15 ailerons).

In strong winds (>15m/s) flaps have to be used at a correct value to climb in front of the ridge, to stay in the maximal lift of the slope

Snap flap must never be desactivated, for races, aerobatics, thermal flights or landings.


Ballast :

The 5 tubes inclued in the kit must be filled with lead, each of them will then be about 190g, and are used to increase the performance depending of the wind speed.

Sections used on Alliaj are low curved (1.2%) and thin (8 to 7.5 %) ; As a consequence, this model doesnít need much ballast.

Despite a lot of pilot thoughts, the ballast weight only depends on the wind speed, not the lift nor cross wind.

Then Alliaj will race :

-empty from 3 to 5m/s

-with 1 ballast from 5 to 7m/s

-with 2 ballasts from 7 to 10m/s

-with 3 ballasts from 10 to 15m/s

-with 4 ballasts from 15 to 20m/s

-with 5 ballasts from 20 to 25m/s.


The only law which can modify this rule is the altitude of the slope, because of the lowerair density