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Everything posted by FlyRatz

  1. Glide Ratio

    yes, I know this behaviour. However at 1400 and below. Hmmm, how accurate is our tachometer? At 1600 all ULS in my hangar are smooth and stable.
  2. Glide Ratio

    How do you call such Instructors? Big ball guys?
  3. Glide Ratio

    Corey, I will do the same test with engine stopped and prop without windmilling. I expect a small amount of a better glide if the engine is stopped. My expectation comes from the experience, that a windmilling engine at idle can lead to a surplus of thrust, if the idle RPM at ground is high. The CT I flew for the test has a idle RPM at ground of about 1600. I am convinced, that this produces drag and not thrust. We will see. I need to wait for better weather and will test again. Markus
  4. Glide Ratio

    You are lucky, wednesday we compared the climb performance and the glide ratio of our CTSWs. I had a logger running while my companion did not. Here are the figures: CTSW 2007, takeoff weight 1027 lb, glide at 65 kn, -12° flaps, engine idle (fixed pitch prop), winds calm (see metar). The result is a glide ratio of 13.2. GlideRatio-DMASV-metar.pdf Glidepath-GoogleEarth.kml
  5. Would you be so kind and share your source with me? A lot of 100 is reasonable for me.
  6. Oh oh, you remind me on something. End of last year, I had bad luck with replacing the doughnuts. I bought the rubber parts from a FIAT Dealer and got rubbish. They lasted for exactly 4 weeks and needed to be replaced again. I got a bad batch as it turned out after inspecting them. The rubber was soft and clammy. As far as I know, FD buys the parts at the same source as I did. So it could be, that you get a bad batch as well if you buy it at FD. Just for your info.
  7. Sinking Floats

    While discussing floats, I have a new theory why one could have a sinking problem and others may have not. Premise: The floats are made of foam, which is closed porous. Airplanes cycle between different altitudes which leads to different atmospheric pressure between takeoff, cruise and landing. If the inner pressure of a foam bubble in relation to the outer atmospheric pressure exceeds a certain limit, the foam structure, building up a bubble, will crack. Conclusion: If an airplane is operated often at high altitudes while the departing and landing fields are at low elevations, this might lead to sinking floats more often, than in the other case. What do you think? Is this theory intelligent or completly idiotish? I think, this could explain why some Rotaxes has problems with floats regardless the float generation used.
  8. Hi swarm intelligence :-) is one of you aware, that the original drip trays do not fit the new cylinderhead design? Rotax has now a CHT-sensor at Cyl#3 just close to the thread where the right side drip tray is mounted. If you have a Dynon and need this CHT-sensor, you will have problems to mount the drip tray. I directed a question to the FD-Headquarter how to solve this, but got no answer until now. As far as I know, there are a lot more CTs in your country equipped with Dynon EMS and the new engine than in Germany. If one of you guys have this config, could you please take a photo of the situation where the right dip tray is bolted? How do they deviate the CHT-Sensor? I am a little bit disappointed by the new FD management. In all Interviews I hear, that they work hard to improve the customer relationship. If you have a concrete question, they dive very deep. Greetings from cold and hazy Germany Markus
  9. Drip Tray and the new cylinderheads

    Hi Roger, There are voices from inside, if you crank the prop very slowly by hand: You want to listen? Click here Chatty gear Edit: Oil is AeroShell (red) Friction test done and friction is at upper limit Gearbox is quiet when cold
  10. Cost to replace/overhaul the engine.

    Labor: I did a replacement recently. I am slow and I am scrupulous and it took me about 70 working hours to replace the engine. My guess is, a man like Roger or Corey could do it in the half?(But they will propably cost at least the double )
  11. Drip Tray and the new cylinderheads

    Boys, do you remember my thread Be careful with the threads on your engine? You see on the pictures the replacement engine while the installation was in progress. There is no need to be nervous about untightened nuts, open hoses or something similar you could see on the pictures ;-) @Bill: you have a sharp eye. Indeed there is very little clearance between the tray and the fuel bowl. For an inspection of the bowls, you need to either remove the carbs or the trays. The latter will be the preferred option. btw: Today the new engine has 3 hours flight time in the logs and the first problem arises. The gear is very chatty if the engine is warm and if you move the prop by hand. Grrrrrrrrrr :-(
  12. Drip Tray and the new cylinderheads

    Hi guys, i come back to this topic with the final solution. FlightDesign created new trays which fit the new cylinder head. The bird is back in the air. Enjoy the pictures
  13. Let's talk about grounds. Again.

    Sounds comprehensible to me. Fingers crossed that holy Ohm left the plane
  14. Be careful with the threads on your engine

    Thanks Corey for asking. I discussed again with my Rotax representative and they persist in their view of things. My interlocutor told me, he had a discussion with the engineering of Rotax in Austria and they actually do not allow to use HeliCoil despite the fact, that there are HeliCoil inserts at some threads of the case (Parts catalog figure 72-20-00-1, item #2). He assumes, leading edge air foils is wrong with their assessment. Now the ship has sailed. The replacement engine is on the way to me.
  15. These days I have some trouble with a 912 ULS, 1400 TSN. The engine has a defective crankshaft bearing. So far so bad. I tried to organize an overhaul at our local service center but Rotax denied to reuse the housing because of a damaged thread. The thread in question is the upper thread for the engine mount on the right side. This is where the long bolt comes in. To my surprise Rotax does not allow to repair the thread using HeliCoil or equivalent. They told me, that even the thread for the crankshaft fixation tool may not be repaired. If the threads are questionable, the housing must be replaced. Unbelievable but true: If a thread is defective, your engine is probably scrap. Don't ask me, why the thread is damaged. When the engine was mounted, the bolt has been tightened using a calibrated torque tool. So be careful out there!
  16. Coolant system pressure leak test

    This little thing is cheap and does a great job detecting coolant leaks: UV Light I recently bought three of them and I appended the topic: "UV Light leakage search" to the Rotax inspection checklist.
  17. Be careful with the threads on your engine

    Hi Dick, Rotax did not say "it s your fault". They only speculated about the cause. I think speculation is just that: Speculation. Nobody wants to pay the cost for a real investigation of the cause. I accepted their offering of an engine in exchange. The old engine remains at Rotax. The bill reads as follows: 1. Overhauled engine in exchange with your defective engine 2. Plus core credit because your engine is completely unusable 3. Minus goodwill from Rotax I do not expect to get the old engine back because of 1. The engine in exchange is ~ 500 Euro cheaper than the repair and overhaul would cost. And it is about 2500 Euro cheaper than a new engine. But: If I would buy a new engine, they would not give me the goodwill AND they would hand me over a second bill for the disassembly and the inspection of my old engine. Racketeers ;-)
  18. Be careful with the threads on your engine

    That's nice! I am very curious what they say.
  19. Be careful with the threads on your engine

    Yes. We prefill the filter and when the spark-plugs are out, the engine is rotated until oil-pressure comes up.
  20. Be careful with the threads on your engine

    The disassembly was done by the service center. I have not seen the bearing. But the fact, that there are bronze coloured chips in the filter mat has a meaning :-)
  21. Be careful with the threads on your engine

    OK, here we go. On the pictures you cannot see the colour of the chips. The chips, pointed to with a blue cable strip, are bronze coloured. The very last picture is the smear of the magnet screw. Due to this situation, I decided to ground the engine. After disassembling, one crankshaft bearing showed defective (the one in the middle). All other parts of the engine were in healthy condition and an overhaul with a new crankshaft would be no problem, if only this shitty thread would be OK. How does this come, what is the cause? Because there are no other findings, it is impossible to determine the cause of this defect. Rotax said something about lubrication problems in company with air in the oil tubes. My opinion is, that if there was a lubrication problem, it would have affected not only one bearing.
  22. Be careful with the threads on your engine

    Hi Dick, at the 100h inspection we found some small chips in the oil filter. If you want, I can upload pictures of the findings. Markus
  23. Drip Tray and the new cylinderheads

    Aaaah, this is the difference. We have the FlightDesign Airbox and the trays mount to the cyl.head. hmmm. Any suggestions? Replace the FD-airbox with the Rotax?? Thank you Tom.
  24. Be careful with the threads on your engine

    Unfortunately no trade in value! Crankcase & crankshaft unusable --> No value! I negotiated a GoodWill of 900 Euros from Rotax because of the early defect. That's all! A replacement engine is on its way.... I can see no technical argumentation for being that strict with threads.
  25. 30° flaperon landings - can be fun - or not

    Excuse me for jumping into this topic. Recently I had some lessons in the Lockheed Super Constellation which is based in Zürich/Switzerland. At high angle of attack this bird develops more drag, than all the six engines are able to overcome. If you would flare this animal, it wont be able to do a go around. I tried it in their training simulator.....and crashed! My lesson learned: Different birds require different techniques when it comes to landing. In Germany we have a lot of short runways (~1000ft). Our acres are much smaller in size than in your country and our roads/highways are crowded and curvy. For an emergency landing you definitely want to be able to do landings at stall speed to have as less energy as possible at touchdown. This is why I teach it similar to Tom. The students learn to land at 15° with the stick all the way back. If they conquer this, I teach them to do the same at 30° and 40°. Later in their career, I have no problem if they do landings with a little more energy in the system as Roger prefers. But they need to be able to do stall landings if necessary. In an simulated emergency I only accept landings at 40° with the stick all the way back (exception: heavy wind with gusts) A good and safe 2018 to all of you, regardless your landing technique :-) Markus