Prototype-Testing in Lesce, Slovenia 2004

"If Friedel doesn't manage to break it then it's ready for production." That's what you can hear from Wilhelm Dirks all the time. Therefore he agreed very much with my plan to take the DG-1000 Turbo prototype to our annual vacation in Lesce-Bled; a place we visited now for the 6th time in a row.

Let me share my experience flying the DG-1000 for 2 1/2 weeks all across the Alps, with the “return to home insurance” provided by this little engine in the back. Each day I had the "problem" to find a partner to fly with me, since my wife prefers to remain firmly on the ground, as you know. However the problem always resolved naturally and led to excited comments from those flying this ship for the first time. Not only that it handles nicely, it has apparently very good glide performance and is particularly quiet.

I have never before flown any glider with such a low noise level. You only have to treat the canopy frames with a little bit of wax to keep them from gnarring. The whole ship provides a very solid impression, surely a good value for the money. But this is nothing new for pilots having already experience with the pure glider version DG-1000S.

New was however the engine and the pending questions about its reliability. Here again this flying vacation provided a positive experience. Sure, some problems came up, but finding them was a purpose of my trip. If the mechanic didn’t secure the exhaust screws with Loctite, then of course they will get loose, as to be expected. However we could easily tighten them again, secured with heat-resistant stop nuts. A similar problem showed up with the battery cable.

But to find those things, we fly our prototypes extensively - nothing unexpected therefore. My trip resulted in 26 improvement requests, which will be incorporated over the next weeks. Then the ship becomes ready for testing at large.

This is what I observed in particular:

The engine management with the new “DEI-NT” is very easy, as mentioned earlier. The almost fully automated system is very reliable. The simplified control procedures eliminate opportunities for mistakes almost completely. This is particularly for flying clubs an important safety improvement. Programming of the DEI used in these flights was not yet finished; it will provide even more capabilities in its final revision. The engine started immediately every time and ran smooth. The noise and vibration level was very low; noise reduction headsets became never necessary. The electric starter is another safety benefit. It allows a full check-out of the engine systems on the ground. Also, briefings including engine operation for transitioning pilots can be done safely on the ground instead in the air, another important advantage for club operations.

The engine has sufficient power to enable a safe return to the home base. Climb performance, currently 160 ft/min (0.8 m/sec), will improve with the final propeller. Currently we use an adjustable propeller to discover the optimum engine speed. The relatively large propeller has high efficiency, also due to the small frontal area of the engine.

The generously dimensioned tank holds 5 US gallons (19 liters). The refueling system is similar to that of the DG-808B, however with one improvement: The DG-1000T has the fuel line connector and control switch located in the engine compartment; eventual fuel spills will not cause unpleasant odor in the cockpit. Refueling is very simple: Just connect the refueling hose, drop the open end into the fuel container and press the yellow button. The onboard pump stops automatically when the tank holds 5 US gallons (19 liters). There is hardly a way to make this simpler.

Equally reliable operated the solar generator, which is smoothly integrated into the fuselage similarly as in the DG-808. Even with the two soaring computers and frequent trials of the engine, we had always enough electric energy available from the main battery with 12 Ah capacity. The installed second battery was actually not necessary.

The new trailer built by Axel Anschau is painted in trendy silver metallic. This looks nice, but requires a stronger ventilation to keep the temperatures under control. At least it is distinct from the “fashionable white” of all the other trailers. Do you like it?

We had no stress with the technology and could fully enjoy the wonderful flights with this extraordinary aircraft. Here we are circling above the Triglav, the highest mountain of Slovenia (2.850m):

 

- k-f-weber -     Translation: Manfred Koethe

Final Choice of a Motor

The Goebler-Hirth motor that I tried in Lesce performed its task well, but the power was not as high as the manufacturer claimed.  With its use, the climb capability of the DG-1000T was somewhat poorer than that of the major competitor's.  It is our intention to bring out an aircraft which, in every aspect, has the best results. 

Because of this, we have decided to use the 2 cylinder Solo Motor 2350C that has been used in other similar aircraft.  With our large, specially developed propeller, we expect a clearly better climb capability along with a very low amount of vibration. 

We will keep posting further developments.  Here is an additional page with the

Technical Data for the DG-1000T