Jump to content

Leaderboard


Popular Content

Showing content with the highest reputation since 15/06/19 in Posts

  1. 3 points
    Its all Ok Councils now have access to landing fees on all RAA aircraft to cover it Just more services provided for our benefit we should pay for
  2. 3 points
    I have a test rig to test the CDI modules I make. It currently can only get to 2000 rpm...BUT I have a new one that is not finished yet but workable. Its driven with a large AC servo motor and it is geared 2 to 1 with a toothed belt and pulley. I can now spin the generator up to 5300 rpm. Its scarey by the way looking at the flywheel running at that speed. My mate who is a guru with electronics (he used to design and build the transmitters on the satellites that deliver your sat tv into remote areas for Optus) is designing a new regulator for the Rotax system. This will allow Lithium batteries and of course normal style etc to be used and safeguards are built into it to prevent overcharge and over current. We did some testing last week on my new test rig and its looking impressive. To get to the voltages that are produced out of the Rotax generator we had a cro on it and also a fluke. At 5300 rpm there was 28v RMS coming out and that equates to 39V peak so you better make sure your capacitor is at least 40V in spec NOT 25v Dont forget the frequency is also extremely high at that RPM. Roger has gone away on a flying holiday as of saturday up to Townsville and over to Darwin in his World Aircraft "Spirit" so if any of the forumites up that way come across him and his wife say hello. Roger will continue working on it when he gets back. The best thing is we are testing in real world by using my test rig and can load and simulate all sorts of issues
  3. 2 points
    Here is a copy of article. Dear Forumites Herewith an incident I had with diesel in petrol. I'm sharing this to create awareness, so here goes: On Saturday I decided, on short notice, to fly to a meeting Outjo to Otjiwarongo (1/2hr), and from there to Tsumeb (2hrs). From the word go I was late for the meeting and had less than an hour to get my Hawk ready. I needed petrol and found my normal fuel container 3/4 full. Which was weird, because I always empty them (What doesn't fit in before a flight gets added after), but what was inside looked and smelled like unleaded, so I just added petrol at the pumps to fill them completely and off I went. During warming up I noticed a little bit of blue smoke coming from the exhaust when looking at it against the sun. By the time I got the hangar doors closed I had already forgotten all about it. En route to Otjiwarongo I found that I burned 11.8l/h instead of the normal 11.0 @ 4,900rpm, but put it down to weird and ignored it further. The EGT's looked slightly lower than normal, but the weather was cooler so that explanation was tagged to the problem. In Otjiwarongo all was normal. I even took a friend for a short scenic flight before I departed to Tsumeb. During the pre-flight in Otjiwarongo I didn't check the oil level. How much oil can one lose in 40 minutes, right? En route I noticed that the 912 UL seemed to run slightly erratic, the revs dipped from 5,000 to 4,800 every now and then. When I applied full throttle the engine responded fast and willingly and settled back on 5,000 easily. This puzzled me, but it was turbulent and I was busy dodging rain showers, so I found another convenient explanation: Obviously the turbulence I ran into caused the motor to labour every now and then. Problem analysed and explained away. On landing in Tsumeb I found my oil container brim-full and every drop of oil that couldn't fit into the tank (which was a lot) spread evenly over the tail feathers. After a whole day of trying to find an explanation (it isn't easy at all to explain 1.5l of oil gained during the flight) I latched onto a possible solution and traced the fuel supply. The "petrol" came from a diesel car that was wrongly filled with petrol at the pumps. The mixture was drained and stored for further use. I had actually witnessed the whole operation and was also concerned that "my aircraft fuel containers" were used for the job, but I'd mos know about it and not forget. Right. The 912 is fine. Except for a red face, so is the pilot. The spark plugs were cleaner than I have ever seen them, it looked like a layer of coke had been loosened from the pistons. We drained and refilled both oil and fuel and changed all filters. The magnetic oil plug was clean except for a single sliver of metal. I'll have the oil analysed to check, but the Hawk behaved very well during the flight back to Outjo, which was conducted at ample altitude for a possible emergency landing. I fly a low compression 4-stroke. With a higher compression engine like the 912 ULS the story may have ended differently, or finally. Thus to repeat my instructor's lessons: • Don't be rushed when tending to your aircraft. • Make sure about your fuel supply. Repeat, make *sure* about your fuel supply. • Don't take deviances from normal lightly. My fuel consumption wasn't normal, neither were the lower EGT's and definitely not the fluctuating revs.
  4. 2 points
    Don’t let the cheaper price of any safety item dictate your purchase decision. You hope you never need it but, if the day ever comes you want it to be reliable and work the best it can. Cheers, Jack.
  5. 2 points
    The "radiator" cap on the Rotax is designed to hold pressure to a certain point and then release coolant into the "over flow" tank/bottle. The cap is also designed to allow coolant to flow back, as the system cools down (in cruise/decent & engine off) the coolant is then drawn back into the cooling system. That's why you only fill your overflow between 1/4 & 1/2 to allow room for the hot coolant to be temporarily stored (if your overflow fills to the top excess fluid will be dumped. If you have doubts about the condition of your radiator cap - purchase a new one (much cheaper from your Ducati Motorcycle dealership)
  6. 2 points
    Downunder I can assure you the later modules will fire a bit lower than 150rpm. Rotax used to quote I think 220 or 240rpm firing but it was usually around the 200 for the older modules. The latest modules will fire at 150 regularly so still be very carefull when burping the engine
  7. 1 point
    Still a WIP, then: Two people briefed on the matter told Reuters that an FAA test pilot during a simulator test last week was running scenarios seeking to intentionally activate the MCAS stall-prevention system. During one activation it took an extended period to recover the stabilizer trim system that is used to control the aircraft, the people said. https://www.theguardian.com/business/2019/jun/26/united-extends-ban-on-boeing-737-max-after-regulator-finds-new-problem
  8. 1 point
    And its done, it took 2 months of active work on it. Lets hope cooling works.
  9. 1 point
    I had a good one and sold it to a friend for his daughter's use and she totalled it in a few days. Easy car to work on (RWD 5 speed man.) Copper said she would have been killed in anything else. Finally admitted she was going a "BIT quick". Nev
  10. 1 point
    Just select Quick Plan and enter your waypoints - then no reference to your current location.
×
×
  • Create New...