DF-02 ready to go into production

[MIO]

Hello everybody,

I want to give you the actual state of affairs on the fully enclosed single-seater DF-02. After 2 years of engineering and testing, the machine is ready for serial production. We will start it within the next weeks, when we have finished german and french microlight homologation.

What's new? Just the most important:

- Rotor and rotorhead: We use the new AVERSO rotor now (extruded aluminium blades) with a new GyroTec rotorhead.

- Test flights: We flew 62 hours on the prototype now.

- Speed: We made 200 km/h IAS. IAS is very near to TAS.

Distribution in the U.S.: We have not decided for a distributor up to now.

Price: The ready-to-fly machines with french or german homologation will be at 29.000€. Pricing for kits is not made yet.

Website (also in english language): www.gyrotec.de , Email: info@gyrotec.de

Video in flight: http://www.youtube.com/watch?v=wWZiHVvFHwI

I am at your disposal for further information.

Regards,

Michael

[Victor Duarte]

Hi Michael,
congratulations !
Your machine is just beautiful and the building is just impressive, each detail is perfect.
I had the occasion to see it fly at le bois de la pierre and it flies sooo well and it's indeed VERY VERY fast.
and, last but not least, you are a kind person that is always willing to listen and always available to give any information.
I wish you the best, you deserve success.
and if you have success, you muit bring some champaign next year :party:

Victor

[jos]

Mihael, you have a winner!!!!

JOS

[Timchick]

Looks great. Can't wait to see one here in the US.

[Mike G]

Michael
I'm happy to see you're ready to put your gyro on the market after all your efforts. Well done.
Where are you based now, the last time we met was at St Ciers.
Can you give any more data comparing the Averso blades to the Sportcopter blades. What differences did you find?

Mike G

[MIO]

Michael
Well done.
Where are you based now, the last time we met was at St Ciers.
Can you give any more data comparing the Averso blades to the Sportcopter blades. What differences did you find?

Mike G

Thank you, Mike.
I'm still at St. Ciers, but no more very long. Last important thing I want to realize here is a dynamic rotor test (3g lift, will be 570/min :flame: at Cognac military airbase (details are secret - surprise, if it works as I want!)
Difficult to compare the finest details of the rotors because I changed the head at the same time, and because I have 7,45m rotor diameter now (sportcopter: 24ft-7,32). Nevertheless:
First of all much higher moment of inertia, roundabout 140 kgm². Reason is the strong extrusion and steel in the blade tips. As the hub bar is 3kg less heavy than SC and the head is nearly half the weight of SC head, the whole system is however just 500g heavier.
It's logic that prerotation takes a little bit longer, but I reach 270/min without wind, 300 with 15 kts wind, which is sufficient.
The max horizontal speed is the same, but gliding angle is quite better (4), and less power is needed at lower speed. OK, the increased diameter, but perhaps because SC is not 8H12 airfoil, too. I think for very lightweight pilots (Julien flew it yesterday) 7,30m or 7,20m will be better. On the other hand, for high altitudes the 7,45 is better - Julien had 600ft/min climb at 8000ft. Without much fuel, I (80kg) can make the approach at 50 km/h now.
With increased inertia, the machine is more stable, means: more comfortable at rough weather and easier for beginners with the Averso rotor. For fast manoeuvers, the SC was more agile - what I personally like a lot. For making slalom in the forest, you need a stronger hand now :rolleyes:
I changed the offset to 25mm. So you can use a trim to adjust the speed you want. The SC system has advantage of lower stick forces (not an advantage for beginners) and of great feeling of the rotor, but for journeying the SC was tedious: 2 minutes without speed control, and I had taken or lost 500ft altitude and 10 km/h airspeed.
The rotorbrake is effective (not to compare to sportcopter), the upper prerotatorparts are nearly the same (Wunderlich parts, thanks to Tom for continuing the enterprise!).
Well, you see that the change of the rotor brought some advantages - but this was not the reason for changing.

See you at St. Ciers?

Michael

[Schlagschrauber]

Hi, dear gyro friends!

In fact I'm new in this forum. But I'm the lucky guy who was the first prospective customer who tested Michael Obermaiers DF02 and so I want to tell you about this experience.

If you remember his postings (“MiO”) in this forum you will know that he is developing the DF02 gyrocopter based on the design of the DF01 of the experienced French constructer Francois Dedieur. Francois unfortunately died February 2006 shortly before the first flight of the DF02.

Since the DF01 this construction underwent a lot of improvements which took Michael much longer than he had ever expected but all together make up a really nice machine. I will describe some of these modifications later on in detail.

I met Michael first at the "Tannkosh" event in Tannheim, Germany (48°00'35.6" N 010°05'57.5" E) about one year ago. Before this meeting I had sent him a bunch of emails with all the stupid beginners questions (I have a PPL since 1981 and some 500 flight hours VFR and IFR but I had no gyro knowledge or experience except one flight on the backseat of a German MT-03 gyrocopter).

Seeing his prototype I closely examined each visible detail and asked for many constructional solutions. Michael never lost his patience and enthusiasm while explaining me all his ideas, solutions and the reasons for his modifications. After a demo flight this afternoon my trust into this machine and its constructor grew.

These were the main features that convinced me from the GyroTec DF02:

The closed Cabin: a closed cabin extends the period significantly in which you can use your gyro in Germany. If I want to fly from A to B it increases the probability to arrive dry. And if I really want to have the wind around my ears I still have the option to remove half of the canopy and fly a "ragtop".

The two-stroke engine: I expect that the two cylinder Hirth engine with the dual ignition and electronic multi point injection will reduce the operation costs without a significant influence on the reliability. The power-to-weight ratio is arguing for itself. And after a look under the cowling of the DF02 I simply hope that the simpler an engine is the less can break down.

The full-aluminium rotor with high inertia: understanding physics you will see the performance- and safety reserves. Initially Michael used Sportcopter rotorblades and -head. But the French Averso rotor "Stella" (extruded aluminium) is still heavier and in combination with Michaels robust but sophisticated rotor head it proved to be the even better combination. There are absolutely no vibrations on the stick.

The overall performance: low mass, high power and this inert rotor allow spectacular manoeuvres. I have seen the 200 km/h test flight with my own eyes. All the performance data on Michaels homepage are real measured values - not calculated or extrapolated as on the homepages of some competitors.

The usage of high-quality standard parts and proven solutions: wherever acceptable in terms of safety best-practice solutions will be used ( airframe welded with real aviation steel, high performing brakes from mountain bikes on the main gear and as a rotor break, ...)

The stability: I know from my own experience about the insufficient directional stability of the fully enclosed two-seater Magni M19 and I heard about some other constructions having the same problem. I never saw any problems of this kind and I also didn't feel any instability during my test flights.

Last but not least: the price! In fact I'd also rather fly a two-seated gyro and impress my female, young, beautiful co-pilots but in reality I was busy most the time to find paying passengers (flying in Europe is real expensive!). So with a limited budget I expect to have the most fun in an affordable single-seater. And if there really will be a young, good looking girl: I will show her heaven in any Magni, MT-03, Piper, Cessna, Rockwell, Diamond, ...

Michael Obermaier also suggested to learn flying in France (as he did) and so I went to the place where he is doing his development and test flights at St. Ciers-sur-Bonnieure (LF1652): 45°51'03.8" N 000°15'57.4" E in the beautiful department “Charente”.
I also had Eric Changeur as a teacher and while having a great time there I made my French gyro licence. Unfortunately there are no unified European regulations yet and so I continued to also get a German licence.

I kept in close contact with Michael and I also met him at the AERO 2007 in Friedrichshafen. Here I saw that Michael had done a lot of delicate work. He also has thought about some simple but effective features which I never saw in any other gyro.

Just to give you an example: the main gear brake and rotor brake levers are both in a most convenient position. Both can be dosed precisely and have an easy but reliable locking mechanism. As soon as I set take off power the gear brake releases automatically.

Further improvements were:

the new rotor head (7075T6 aluminium)


improvements on the electrical trim


optimization tests with many props at different blade angles


new outside and interior design


modifications for better functionality of the avionics (antenna positions, ...)


And finally I returned to France four weeks ago to repeat some emergency exercises (engine failures, outlandings, ...) with Eric Changeur and to make up my final decision about "to buy or not to buy" the DF02.

Michael was also there to finalize his work for the French and German microlight homologation. Being fascinated by all the progress I asked Michael if I might test his DF02 prototype. After some flights on the Magni M16 I convinced him that I'm already "ripe" for his “baby”.

And now all about these two test flights:

First of all: for a "king size" man as I am (106 kg = 234 lb weight over 174 cm = 5 ft 8.5 in length) it is actually not possible to fill the tank completely and to stay "microlight" at the same time! (As a consequence I glued a photo of the DF02 on my fridge that should help me to reduce my weight: my plan is to be able to operate the DF02 longer than 2 hours at a time legally!

Despite of my embonpoint the DF02 fits like a glove (but you shouldn't be thicker or much taller than I am: A new canopy shape will help you if you are taller. But your weight should not exceed the 210 lb. You can't betray the physics and gyros react on overweight with considerably reduced performance.

But back to my flight: close the canopy, master on, ignition 1 and 2 on, fuel pump on, coolant pump on. Prop area clear? Starting engine!
The engine starts with a typical 2-stroke sound, it runs smoothly at 2500 RPM or above. It reacts immediately on changes in the throttle.

The warm-up of the engine is much shorter than with a 4-stroke engine (lower mass!). There is no oil pressure or oil temperature. Instead you have 2 CHT and 2 EGT indications.
Radio on, release the rudder lock (to take care of the control rods on this bumpy grass surface) and start to taxi immediately.

The nose wheel steering is very direct; the landing gear struts absorb all bumps of the meadow sufficiently. After rolling 150 m to the runway the engine has reached the required temperature.

Approach Sector(s) clear? I taxi into position, engage the gear breaks and lock them, release the rotor break, engage the prerotator (mechanic via cardan and bendix). The rotor can be accelerated quite fast. Beyond the 200 rotor RPM I pull on the stick back completely and increase the motor RPM continuously to beyond 260 RPM.
When reaching take off power the gear breaks release automatically and someone is kicking in my back!
At least that’s what it feels like!

I reduce the angle of attack of the rotor as soon as the front wheel lifts off and some split seconds later the DF02 is airborne.
In the first moment I'm a little bit confused about the engine torque: it is just the opposite of what I had experienced 250 times on Rotax-driven Gyros. And then my reactions are definitely too explicit: Flying the DF02 is like wearing wings on your own back: incredibly direct!

But maybe it's just because this is the most lightweight plane I ever steered through the air: only a third of a DA40 Katana, a fourth of a Cessna 182, 65% of a MT-03 or Magni M16 gyrocopter!

With 80 km/h IAS at 6300 motor RPM I perform my initial climb, approximately with the same rate of climb as in the 115 HP Magni. At higher RPM the Hirth engine sounds more pleasant. But a good noise absorbing headset is no false investment anyway. Beneath motor and prop I can't perceive the rotor or airflow noise. After levelling off the speed increases to 120 km/h and I reduce the power setting: I'm not in a hurry!

Now I have some turns and manoeuvres on my program. I recognize that I have to get used to these very direct reactions on my control movements: I have to use the tips of my toes for the rudder and my fingertips for the stick. (I'm always comparing to the Magni which I was used before!)

It was really pure fun when I tried to imitate some of the manoeuvres that Michael had shown to me several times. But my first approach is just much too fast and I decide to do an overshoot first. But the second approach is perfect and I also succeed to perform a good landing: the rotor inertia really helps! No vibrations or stickshakes!

Apply the gear breaks, pushing the stick forward and against the side wind, turn around, return to the hangar, stop the rotor, cut off the engine, switch off all electrical systems, open the canopy!

I feel very enthusiastic in this moment! Great! I have dreamt to do this for more than one year and now I did it! Michael is crouching beneath the cockpit and listens interested to my first impressions while I'm still relaxing in the cockpit.

I already wanted to climb out and celebrate this moment with a little beer, but Michael offered me to repeat the whole thing once more. So we checked the fuel and I started for another flight. Now I wanted to extend my tests but sunset and a CB (with at least one flash of lightning) north of the field made me return earlier than I wanted.

I think that also the second landing was very acceptable. But nevertheless I'm looking forward to the moment when I will have the skills to control this machine as good as Michael does and to use its full potential.

We pushed all the gyros from the apron into the hangar before they would get wet from the thunderstorm and while the first drops were falling on the tin roof of the hangar we finally had our "after landing beer": Michael and I were celebrating his 200 km/h test flight (108 kts) and my "maiden" flight!

Conclusion:
The DF02 met all my expectations, and I'm going to buy one with the German homologation.
It lasted very long to bring the construction to this state but I think that the result is a really well developed microlight multi purpose gyro:

at the same time it will be a fun machine and a machine for trips over 200 NM (if you do not need much more luggage than underwear, a toothbrush and your credit card),


it can be operated semi-open or closed


and I think it will be affordable.


If you doubt in what I told you:
I recorded some of Michaels test flights with my digital photo camera and set them into YouTube:

http://www.youtube.com/watch?v=wWZiHVvFHwI => one of Michaels demo flights (with Musik - I like this clip).


http://www.youtube.com/watch?v=AU9mQjH5_jU => the same flight (but without music - Michael prefers this one).


http://www.youtube.com/watch?v=eMSj9WOOD7U => just another test flight of Michael during rainy weather conditions.


http://www.youtube.com/watch?v=iyqBe7eFYUo => the start and 2 overshoots during the flights I described above.


Perhaps I'll be making some more videos out of my raw material - just search from time to time with the keyword „GyroTec“.

Best regards, Holger

[greeny]

And I thought it WAS in production ..

At least the 'preliminary' one I am building from drawings - see picture with some of the smaller parts of the frame.

[MIO]

We made a rotor test at about 600 rpm.

http://www.gyrotec.de/images/Videos/FlyingCarTrailer.wmv

Warning: We refuse any responsibility if you do tests like that.

[airbiscuit]

I've been looking at some video's of the DF02. It really looks nice. I thought about the Xenon, but I hear the insurance is really high. Besides, I don't know that any of my famly/friends would go for a ride. Does anyone know the status of the DF02?

Thanks Scott