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Downunder

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Everything posted by Downunder

  1. Downunder
    The rotax has a built-in generator on the rear of the engine, attached directly to the crankshaft. This powers the ignition system and supplies power via the Regulator to charge the battery.
  2. Downunder
    That's the first time I've heard of duty on aircraft parts. As I understood it, duty was dropped when gst come in. Interesting.
  3. Downunder
    Do you know what a shill is Skippy?
  4. Downunder
    There is no "open market" for new Rotax engines. They are one brand and one manufacturer. New engines are only sold by Rotax dealers..... I imagine aircraft manufacturers obtain them at a better price but are probably contractually restrained from selling just engines. Other companies like Honda also keep a close hold on their products and subsidiary international branches. Alot to do with brand and market protection, not only profit.
  5. Downunder
    Hard enough to tune with one carb on a 4 cyl......and even more difficult on a 6 cyl. Spend the rest of your life playing with runner lengths and carbs or be done with it and fit electronic fuel injection (with individual cylinder mixture adjustment).......if you want perfection. Accept the mixture variation of a carb fed engine or put your head in the sand with egt monitoring of one cyl. As far as the 912 manifold goes. The front two cylinders run rich under 5000 but all evens up from then on with even egt's.
  6. Downunder
    Definately have 2 mag switches. I don't like key start, especially one with the mags included. I would prefer a momentary switch for "start". No alternator on 912, though it is a factory option. (I know someone with one for sale) Battery/starter cable is critical with the 912. Longer length, greater diameter. Multistrand will give you more capacity again. There are calculations online. Use good quality. From memory 16mm2 is the minimum recommended by Rotax. My battery in behind the seat and 16mm2 multistrand is adequate. Further away and I'd probably use bigger dia. Use industrial lugs on cable ends, not automotive. I use carbon grease on connections. Do use a battery isolator..... one with a key. Failure to set up correctly and you will start "doing" sprag clutches..... not an inexpensive exercise. Use a good battery. Not only helps with good starting but I think it helps stabilise the regulator which is a known failure point.
  7. Downunder
    An aircraft may glide better without the prop as it has less drag. In an ultralight you push nose down to maintain airspeed when power is lost. This is virtually instant, power lost-nose down. The instructor will train and test this. I always get it in my bfr. They want to see you push the nose down straight away..... The GA theory of "use airspeed and momentum to gain altitude" does not apply.
  8. Downunder
    https://www.recreationalflying.com/threads/heres-an-odd-question.68345/
  9. Downunder
    Who's the dealer?
  10. Downunder
    https://generalaviationnews.com/2013/06/27/rotax-912-is-better-than-predicted/ Note...120 degrees Celsius has got to be wrong. Should be Fahrenheit. ...........91 octane fuel stated is American MON rated fuel. Basically same as our 95 RON rated fuel.
  11. Downunder
    Basic info on the engine and list of aircraft the engine is fitted to... https://en.m.wikipedia.org/wiki/Rotax_912 The 912 uls is a 100hp carburetor fed engine. (The most popular 912) The 912iS is a fuel injected uls, and uses about 30% less fuel. The 912 ul is the 80hp version, carburetor fed. The 914 is the 115hp turbocharged engine. The latest is the 915iS. A 140hp fuel injected, turbocharged engine.
  12. Downunder
    100hp is 20hp MORE than the Jab ....... The 912uls is the most popular light aircraft engine in the world. It has it's quirks but if set up correctly is super reliable. The preferred fuel is unleaded. 95 or 98. This will save you money not only in purchase price but in less servicing and reliability throughout the engine life which is 2000 hrs plus. Mixing avgas in at any ratio is not problem. I would think at 80kts you maybe using less than 17lph depending on prop and weight set up. Parts are more expensive but I think there is less major servicing throughout the engine life. There are may experienced Rotax mechanics around. I don't find the servicing difficult but it would be slightly more complex than a Jab..... perhaps more on par with a water cooled motorcycle engine.
  13. Downunder
    https://www.flyingmag.com/technique/accidents/aftermath-pattern-failure/
  14. Downunder
    I chose # 2 for all the above reasons. There is FAR more aircraft to choose from in the market and ownership costs are close to identical I would think. I probably would not buy one under 600kg mtow either..... If you fly a 2 seater as a 1 seater, you can then carry a massive amount of gear, so not really "30kg bags". I know somebody with a #1. Not my cup of tea..... There's the odd #1 pilot that will go places but most go in circles around their ctaf or farm. Seeing the same tree, road, fence over and over would drive me insane, but if it floats their boat, good for them.
  15. Downunder
    Does that mean he doesn't get knowledge, contacts and leverage for his AVIATION businesses which ultimately end up as cash in the bank? I'm not saying it is wrong, but he is not running the RAA for purely altruistic reasons......
  16. Downunder
    You'd be amazed the number of times the Forrest caretaker has had to run some jerry cans down the railway line road to aircraft and helicopters making precautionary landings at one of those strips...... Depending on how rutted and muddy the road is, you wouldn't be there too long...
  17. Downunder
    I think he means the fixed horizontal cable tie down found at airports that you tie on to has the spring/flex inbuilt. However I have camping ropes that I can use with the extentions springs you describe for tieing down if I choose them.
  18. Downunder
    Aircraft are NOT 600kg tied down......from 300 to 400 with fuel and gear. Wing section defines the lift generated. Depending on wind strength and direction, the wings can get a rocking motion happening putting "snap" loads on components. I've seen this work pegs out of the ground so personally (with a high lift wing) try to secure it to cables or blocks. I always fuel to full asap if needing to tie down to get as much weight in as possible.
  19. Downunder
    https://beacons.amsa.gov.au/ There are a few brands. Prices around $300 aud. https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=plb&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=extendable+prybar
  20. Downunder
    Unless you're a proffesional pilot flying city or major regional routes, ozrunways on an apple or android device of your choice is hard to beat. If you have a tablet or smart phone it is free to try. Ozrunways also have adsb-in capability. I had jepessen maps initally in my Dynon. It was fairly poor and expensive for a country rec pilot. More commercial oriented was my impression.
  21. Downunder
    Would rubber lubricant be suitable? https://www.penriteoil.com.au/products/rubber-grease
  22. Downunder
    I think there maybe more value in purchasing an aircraft with what you want already installed. I can't see the 172 I mentioned gaining anywhere near the 50k that was spent. Instead of purchasing an average 172 and spending that amount, there would be more value in a newer 172...
  23. Downunder
    It's easy to sit here and write about mech pump failures and "simply" turning on the electric pump. And it's easy to discuss that the engine "should" keep running under gravity feed. We also talk about engine failures and how easy it "should" be to glide to a suitable landing area, however the dead and maimed results indicate it may not be as easy in practice as in theory. The aircraft was designed WITH a functioning and servicable mechanical pump. I'd stick with that.
  24. Downunder
    Rotax fuel pumps have a drain hole between diaphragm and engine to drain fuel from any leaks. Maybe your pump has one Too? My concern with the diaphragm would be deterioration in the context of time in service. Heat and time are the enemy of any rubber or synthetic flexible material.....discounting the long term effects of the fuel used. If the pump is "branded" and disassembly is possible, you may be able to source parts or get one cheaper than an aircraft manufacturer can supply. But..... If it's 22 years old unfortunately I would recommend complete replacement and be grateful for it's long and reliable service.
  25. Downunder
    Yes, electric supercharger is more accurate. https://en.m.wikipedia.org/wiki/Electric_supercharger It's just a concept I think about occasionally. In a fixed pitch prop at WOT, rpm reduces on take off and climb. A supercharged boost in rpm, hence power, would allow shorter take of distance and faster climb out. Either a standard climb angle at a faster speed or greater angle at published climb speed. Batteries carried would allow X minutes of use and be recharged by the engine. I wonder if an inline RC EDF motor/unit (or two) could be used? Being smaller and lighter than a conventional turbo type turbine and housing.
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