This version is based on the idea to obtain an aircraft with an improved operative range and an incremented cruise speed. To obtain this we have decided to change the wing, introducing a delta configuration, remove the tailplane increasing the foreplane surfaces and replace the two original turboprops with three Williams International FJ33-2 turbofans that provide to the plane a thrust of 21,75 kN. These engine are positioned two under the wing and one in the tail.

In the first solution we had positioned the two nacelle at 30cm from the fuselage, but after we had noticed that this configuration cause the creation of a transonic speeds of air flow, we have decided to increase that distance to 50 cm. This because we can imagine this narrowing as the pinched part of the De Laval nozzle. As we know in this point there is the maximum speed and the minimum pressure, so it is possible for an aircraft that flies at speed next to transonic to generate in proximity of narrowing a transonic flow that increase the induced drag, and that cause an inefficiency of aerodynamic structures. Analysing the features of the new airplane and its needs, as for example the necessity to equip it with three engines, we have decided to remove the tailplane, increase the foreplane surfaces and move the wing backward. Thanks to an analysis of the moments of forces generated by all lifting surfaces we were able to maintain unchanged the barycentre location moving backward the wing of only 9 cm and increasing the foreplane area from 2,19 m2 to 2,40 m2. To generate the needed moments and forces, we have introduced some new mobile surfaces. First, to compensate the lack of the tailplane, we allow the symmetric motion of the foreplane that becomes a canard.

Canard:
The foreplane, that in the P180 has only the function of stabilizer, in the P180 3xFJ33-2 has a new function, now it has to replace the tailplane. To obtain this we have transformed it into a canard that, with an increase surface of 2,40m2, is able to create the needed moment of forces necessary to make the plane to take off. We have also maintained the two edge-flaps positioned under the tail useful to maintain a good cruise stability and to create some additional lift forces.

Wing:
In the beginning the Piaggio P180 has a straight wing with a profile that is not a standard Naca but a internal Piaggio Standard. At the root it has a PE 1491 section and the tip the PE 1332G. The new installed wing has a Delta configuration, this in order to take advantage from the adding of thrust that improves the max speed of the plane. For this wing we will use Standard Naca profile. The percentage thickness of these sections is lower than the original one at the root to compensate the improved chord and remain the same at the tip to support the weight of the winglets. To obtain an acceptable variation in speed (however not superior to 10%) we had to sweep back the leading edge until 20°, and to maintain the same wing loading without increasing the drag coefficient we have to reduce the wing span at 13,20m and increased the root chord at 2,50m. For the root section we used a NA63A411 while at the tip we maintained a profile similar to the original one, but NACA (NACA 4412).

As we can see the induced drag result increased from the original value (0.092 instead of 0.082). Because of this we have decided to apply the winglets that reduce the creation of wingtip vortices to induced a 5% decrement of the drag coefficient (CdI) necessary not to obtain a too high value of the drag during the take-off. To increase the efficiency of the wing is possible to apply a series of parallel vortex generator that force the flow go straight above the wing reducing the possibility of flow separation (cause a loss of lift) with the creation of turbulent flow

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Wing Materials:
The wing is one of the most stressed part of the plane, in fact this structure must resist torsion, blending and traction forces created from the action of thrust of the engine and from the drag of the air flow on the aerodynamic section. For this reason we must use different materials to build the wing. The internal structure of the wing is composed with 2 main spars and 16 ribs that make possible the maintenance of the wing shape also when high stressed, typically in the last moments of the flight when the fuel tanks are empty and so cannot oppose their weight to lift force. As in the original version the wing is made in aluminium while the mobile parts are made of composites, but this version has a delta configuration of the wing that make possible to reduce the wing weight without compromising its structure.

Lift distribution on wing:
As we can observe in the graph below the higher lift is concentrated in the part of the wing near to the fuselage more than in case of the original wing so that the extremity stress results inferior as the structure complexity needed to support it.

Fuselage:
The structure of this plane is the same of the original one except for some little changes needed to sustain the new wing, the canard and the third engine. So the central former, originally used to sustain the turboprops, was removed and the posterior one was moved backwards. The introduction of the central engine inside the plane requires the use of two air inlet positioned on the sides of the fuselage, above the wing, while nothing of the structure has to change because the formers and the stringers, used to sustain the tail, can be used also for the engine body. On the nose, to introduce the mobile canard, we have to change the sustain of the foreplane mounting two bearing to make possible the rotation around its axis.

Engines (turbofan):
To increase the thrust we have mounted three Williams International FJ33-2 turbofan engine, two under the wing and one in the back of the fuselage. This one is positioned inside the structure, because after a fast analysis we notice that that third engine could caused some aerodynamic noise and structural problem. To made possible this solution we had to introduce two air inlet above the fuselage.

Weight analysis:
The presence of three engines and the new position of the wing can involve the regression of the CM, that instead remain almost in the same position. This because the total weight of the engines is almost the same of the turboprops previously mounted, the weight of the wing is lower and the mass of the tailplane removed is not negligible (105,33 kg). As it is possible to observe from these values the Center of Masses moves backward of only 1.6 cm, thing that gives us the possibility to maintain the landing gear in the same position as on the original plane. The same is for all other things inside the fuselage like fuel tanks, but also systems and equipment.

Landing gear:
The landing gear of the modified version of the Piaggio P180 is the same of the older one, in fact for all the taxing phase the plane is supported by a tricycle. This arrangement as one gear strut in front, called nose wheel, and two main gears slightly after the gravity center. These are allocated in the sides of the fuselage under the wing.
Wheel distance (nose-back): 5.79 [m]
Distance from the barycentre to back wheels: 0.40 [m]
Load on back wheels: 2x23922 [N] ≈ 2438 [kg]
Load on nose wheels: 3550.59 [N] ≈ 363 [kg]

Cockpit:
This plane is provided with some of the most advanced flight control systems. The cockpit of the P180 3xFJ is essentially the same of the original version, it changes only in some flight controls for the engines.

Flight Controls: Control surfaces are connected to the pilot controls via cables in a closed loop system. Primary controls are made up of ailerons, canard (as elevator) and rudder. The control of the rotation of the nose wheel and the rudder is made with a couple of pedals hinged on the cockpit floor, in dual-pilot control configuration.

The pitch control system in an all moving canard assembly. The canard provide primary pitch control and is made up of two separated surfaces hinged to the fuselage nose.

Differential ailerons provide roll control. In the original version the aileron is equipped with a trim tab on its right, while in the modified version we have to adopt electro-mechanical systems to apply small corrections that enables the pilot to control the plane improving the handling qualities.

The flap systems consists of two mechanically independent sets of flaps: main wing outboard and inboard flaps. Each set of left and right flaps is mechanically interconnected and the operation of all flaps is synchronized by an electronic control unit that controls the power supply to the flap D.C. motors.

X-Plane model:
Additionally to see if our version might fly we have created a simplified model on X-Plane a flight simulator with FAA-certification for flight training. After this test we have notice that the plane has some stability problems, as showed in the images below, but in general it can fly without many difficulties.