D2 twoseater

 

 

A further development of the single seater is the two seater. Besides the demand for an extra seat there was also the need for a very large cabin with an even floor, a high payload and a longer range. As engine the very common Rotax 912 S is chosen.

The planform of the basic wing is the same as that of the D1. Overall dimensions are 1,2 x bigger than the D1, which gives it in theory 1,44 x as much wing area, in practice this is 1,5 x due to the turtledeck that extends behind the wing.

As with the D1 the wings are foldable to save the money for the hangar and the monowheel landing gear with steering main wheel is also adopted.

A difference is the tail wheel. In the D1 this is mounted in a fixed belly fin. While flying the suspension is in the out position, so that half of the wheel is in the airstream, giving extra drag. With the D2 the belly fin is attached to the wheel fork and goes up and down with the wheel, so the wheel protrudes only the minimum.

Getting in and out is also different. With the D1 you have to walk over the rear part of the wing and hold on to the fin. Because of the wide cockpit and smaller fin this is no longer possible in the D2. Therefor a removable ladder is used to climb onto the wing.

The main landing gear is at the same time more simple and has more travel so that the turning circle is smaller than with the D1.

The D2 has one stick in the centre that can be operated by the 2 pilots, as a consequence 2 gas levers are installed. The brake lever, operating the hydraulic disc brake of the main wheel, is mounted on the stick, the oil reservoir is integrated in the handle.

In the D2 prototype all the instruments are on the left side of the instrument panel: EFIS, ASI, altimeter, slip indicator and autopilot, on the far right are the engine instruments, Engibox, voltmeter, propeller lever, and radio and transponder, keeping the centre console free for the iPad for navigation. On the right side is a glove compartment. Of course this can be adapted to ones personal preferences.

In the tunnel is the fuel selector with fuel pressure indicator, in this way no fuel lines are inside the cockpit.

The wings can be folded like with the D1. The stringers of centre section and outboard wings main spar are connected with brackets and inner hex.socket bolts. These bolts can be tightened by means of a long spanner that goes in via the wingtip through a plastic tube. Tightening is by torque: the long key has to turn 45°back after tensioning, this secures the right torsion. The advantage of this sytem is that there are no tight fit parts in the wing connection that can wear. The bolts are industrial bolts that are commonly availabe and can be changed easily.

 

The empty weight of the D2 prototype is only 275 kg, giving it a payload of 325 kg, so more than its own weight! With a tank content of 2x 120 ltr the endurance can be as long as 8 hrs, at a speed of 200 km/h the fuel consumption is 15 l/h, endurance 7,5 hrs with ½ hr reserve, so the range is 1500 km (without reserve).

At a speed of 240 km/hr the consumption is 18 l/hr, this gives also a range of 1500 km.

The structure is of aluminum with ribs made from hard foam, this, together with the light but powerful Rotax, gives the very light airframe.

The cockpit is of the sliding type, giving the possibility to taxi with the cockpit open on warm days.