Flight test of new "all-metal" aeroplane from the Czech Republic. Prepared by the Test Department.
Small aeroplane which flies HIGH – ALTO
Inspired by several bestsellers from the American school of the eighties, the Alto TW 3300 aircraft promises a racing performance. This will doubtlessly be achieved as soon as the machine is set up. Once characteristic feature is the unusual wheel used to steer the craft.
Sauro Salvucci (Aviomarche) presents a new model from the Czech Republic. It is called the Alto. We don’t know what the real meaning of the word “alto” is in its original language, but if we take its literal translation into Italian it doesn’t seem a particularly suitable word to define this plane, which looks flimsy yet promises racing features. The shape of this aircraft is reminiscent of the RV 7 Van´s Aircraft and Sonerai II. The Alto TW 3300 is made entirely of metal and consists of a fuselage and ribs in a rectangular cross-section rounded at the top and connected with reinforcing struts. The cockpit is a natural extension of the fuselage with a retractable cover at the front, which gradually flattens out to a fireproof partition to which the steel engine bed is screwed.
The engine covers are made of fibreglass. The undercarriage is spurred, with the main landing gear fitted with fibreglass springs and with a cogged wheel connected to the foot gear-control lever. The wing is rectangular in shape and is equipped with an aileron and a flap. The engine is a six-cylinder Jabiru 3300, 120 horsepower at 3,300 rpm with a direct twin-bladed propeller. Considering the high rpm speed the diameter of the propeller is unavoidably limited, and as “nothing is for free” as regards aerodynamics, the traction is also reduced with respect to the performance as supplied. The manufacturer is fully aware of this fact, which is why they have announced the introduction of a new version of the Alto which uses a Rotax 912 S engine fitted with a reducer, allowing for greater traction at the expense of horsepower.
The manufacturer has, with foresight, reduced the maximum speed to 250 km/h. With the increasing performance a threshold of 300 km/h is easily accessible.
Small aeroplane which flies high – Alto
It is very easy to climb onto the wing once the landing flap is fully open. This time it is easier to access the pilot’s cockpit thanks to a handle at the top of the fuselage and a completely clear floor. The cockpit is spacious, snug, and fitted with two comfortable seats. The console is equipped with the basic range of flight instruments. The wing-flaps and top rudders are controlled using two steering-wheels in the middle of the console, providing ample leg space.
At first glance it seems that the mechanical design of the drive-chain connected with the steering-wheels is not the best solution. We definitely noted a certain flexibility of the system and residual friction.
The lever for the lift flaps and the trim controls are situated on a central column and are easily manipulated. Visibility at the front is slightly limited by the height of the console panel and reduced by the heat-moulded glass. Closing the cockpit and starting the engine works perfectly.
When taxiing the machine is easily controlled with the foot pedal to a turning radius of six or seven metres. If you need to turn the plane in a narrower curve it is best to use the brakes, which are highly efficient. Two fibreglass leaf springs ensure good suspension, even on very uneven surfaces. Let’s start the engine and fly! We take off at 70 km/h, after 14 seconds of acceleration. When ascending the climb-rate indicator remains at 4 m/s. Both performances are somewhat weaker than expected. Longitudinal static stability is a little more modest at all speeds. Sideways stability is low, almost non-existent when banking the plane, while in-flight stability is excellent, with levelling off being rather fast.
When in cruise mode the anemometer is at 200 km/h. The nose of the plane hardly dips, the machine slips lightly into the air and easily reaches the speeds of VNE 250 km/h as stated by the manufacturer and which seem rather restrictive for this particular plane. We assume that it is easy to achieve VNE in direct flight with a slight increase in engine traction.
| Comfort, cockpit|| 10 Ample space available, thanks to steering-wheels|
| Handling on the ground|| 8 Easy to control|
| Taxiing, landing run|| 9 Good suspension, efficient damping|
| Start, take-off|| 8 Good steering control, although performances somewhat weaker than expected|
| Longitudinal stability|| 7-8 Slightly positive|
| Sideways stability|| 7-8 Good direct-flight stability|
| Speed loss|| 9 Standard, the nose of the aircraft drops slightly|
| Cruising flight|| 8-9 Good performance, slightly "jumpy" handling|
| Steering control|| 9 Adequate for this type of machine|
| Maneuverability|| 8 Excellent at high speeds, somewhat less so at lower speeds|
| Landing|| 7 With care. Longer sliding|
The forces controlling the ailerons and the top rudder are weak. Likewise, the ratio between the forces expended on controlling the aileron, the top rudder and the foot gear control lever need to be adjusted.
When approaching stalling speed the aircraft behaves in the traditional manner, with a slightly premature loss of the effect of the ailerons. The nose dips gently and the controls are sufficient to maintain the plane during controlled speed loss. The craft is easy to control like this using the foot gear control lever, although it must be done in time, as reactions are somewhat fast.
When gliding with the engine at minimum the performance of the machine is rather high, certainly over 14. The performance also remains high when approaching the ground and leveling out with the lift flaps fully extended. In the final phase at 120 km/h and with the engine still at minimum the climb-rate indicator does not rise faster than one and a half metres per second, forcing us to land as if we were in a glider.
The landing run is up to 150 metres, without braking.
All in all we think the Alto 3300 is a small, extremely elegant and good-looking machine which will certainly appeal to those who love high speeds. The aircraft has all the potential to be a fast machine.
From a certain aerodynamic point of view we would appreciate better stability with this machine. To improve the controls it will be sufficient to adjust some of the settings which are naturally typical for this prototype. Our overall assessment of the Alto 3300 is without a doubt a positive one, especially if we consider how it is expected to develop in the future.