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Nobody

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Posts posted by Nobody

  1. I wonder if they argue about aviation on the renewable energy forum?..

    Perhaps I was being too subtle. I was trying to point out that if pilots won't look out for aviations interests do we really expect aviation to get any attention and support from anyone else. This thread is a classic example of how Australian Pilots won't band together to protect their interests. They are much happier squabbling about(but still important) non aviation topics.

     

     

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  2. I have sent the letter below to my local member. Hopefully others on this site will agree enough to send something along the same lines to their members. If we don't speak up then the silliness will get passed.

     

    I write to you, my local member, to ask that you vote against the “Air Services Amendment Bill 2016” recently proposed by Adam Bant in the House of Representatives. The proposed legislation is poorly thought through, illogical and asks for things that already exist. This bill, if implemented, will have a significant negative impact on general aviation in Melbourne and Australia more generally.

     

     

     

    The proposed bill contains an amendment that would prohibit aircraft from flying within 5km of Melbourne at a height less than 2000m. This would mean that small aircraft ravelling west from Moorabbin airport or into Essendon airport would be required to operate through the controlled airspace associated with the large transport aircraft around Tullamarine airport. Small aircraft operating in this area are already required to operate above 1000 feet under the civil aviation regulations. At such a height the noise emitted from a small aircraft is significantly less than other general city noises like trams and vehicle traffic. The proposal unnecessarily restricts aircraft movements for no benefit.

     

     

     

    The proposal to allow for anyone affected in any way by air traffic to require Airservices Australia to review flight paths is unworkable. This would divert the limited resources of Airservices Australia into endless reviews even where no adverse impact to people on the ground is demonstrated. It will provide the opportunity for vexatious complaints to clog up the system diverting resources away from Airservices Australia’s other essential tasks.

     

     

     

    The proposed legislation also asks for the creation of an “Aircraft Noise Ombudsman” despite the fact that such an organisation already exists to resolve complaints about aircraft noise.

     

     

     

    Please don't vote for this proposed amendment.

     

     

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  3. I don't think that the residential expansion and changes in land use will lead to higher wind speed on sea breeze days for a few reasons.

     

    Firstly the sea breeze relies on convection of the inland air creating a void for the sea air to move into. Soon after the sea breeze arrives the convection diminishes. This is not really because the cool air stops the heating but that the air becomes stable as there is now cooler air under the warmer air and the air has become stable. see the earlier discussion about stability here Weather Conditions Analysis. What this will mean is that the sea bree affect is itself in equilibrium. The sea bress destroys the conditions that create it.

     

    When you look at sea breezes around the world they all have about the same peak velocities (approx 20 knots) despite wide variation in the terrain that causes them.

     

    A good discussion of sea breezes is in the book by Frank Bethwaite "High Performance sailing" https://www.amazon.com/High-Performance-Sailing-Faster-Techniques/dp/1408124912

     

     

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  4. I just looked up Vans price for an o-320 for fixed pitch prop, ie the cheapest 160hp engine. US$26700 OR ABOUT 36000 A dollars, plus freight of course. Not sure what a Rotax would cost and they don't make 160hp models anyway, but 1 Lycoming would be cheaper than the equivalent hp in Rotax engines.

    Yenn, This is exactly my thinking, an experimental lycoming is not bad value per horse power, compared to a rotax. If you take the price for the price for the 912 in USD as $17692 from here then you get $176/HP. If you take the 0-320 numbers in your post you get $166/HP.

     

     

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  5. The continued anti technology attitude displayed in this forum is frustrating. The modern technology has the ability to provide audible warnings that means that the head can be out of the cockpit.

     

    The "seat of the pants feel" as you approach the stall changes significantly in a steep turn. The increased G loading results in a higher stall speed in the turn and the higher airspeed means that the controls still feel effective and heavy at the stall, making it hard to "feel how" close you are to a stall. It is why the turn base to final is so deadly.

     

     

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  6. The requirement for certification is copied from 14 CFR 23.207 below. The 5 knots worth of warning is hard to achieve through aerodynamic methods/buffeting alone and so most aircraft need some audible warning.

     

    Roundsounds, over 100 years after the first flight pilots continue to crash aircraft and cause injury and death by stalling. Significant research from the USA has shown that Angle of attack indicators, with audiable warnings, significantly reduce the rate of loss of control incidents, to the extent that the FAA has relaxed the rules requiring engineering approval to fit them to existing aircraft to encourage wider adoption.

     

    a) There must be a clear and distinctive stall warning, with the flaps and landing gear in any normal position, in straight and turning flight.

    (b) The stall warning may be furnished either through the inherent aerodynamic qualities of the airplane or by a device that will give clearly distinguishable indications under expected conditions of flight. However, a visual stall warning device that requires the attention of the crew within the cockpit is not acceptable by itself.

     

    © During the stall tests required by § 23.201(b) and § 23.203(a)(1), the stall warning must begin at a speed exceeding the stalling speed by a margin of not less than 5 knots and must continue until the stall occurs.

     

    (d) When following procedures furnished in accordance with § 23.1585, the stall warning must not occur during a takeoff with all engines operating, a takeoff continued with one engine inoperative, or during an approach to landing.

     

    (e) During the stall tests required by § 23.203(a)(2), the stall warning must begin sufficiently in advance of the stall for the stall to be averted by pilot action taken after the stall warning first occurs.

     

    (f) For acrobatic category airplanes, an artificial stall warning may be mutable, provided that it is armed automatically during takeoff and rearmed automatically in the approach configuration.

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  7. Consider an rv-9. They have good varying capacity, good efficiency and will cruise about 140knots very economically.

     

    A few SAAA guys here in sydney have recently rebuilt Lycoming engines for their RVs. They buy a core and get a LAME to help take it apart. They then send the parts out for inspection and machining, buy new experimental cylinders, sell the old ones to someone overhauling a certified engine and help the LAME put it back together in a weekend. The engine was working out about $18k

     

     

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  8. The diesels that do have promise for aviation use are 2 stroke. You trade off fuel efficiency but gain Power to Weight ratio. They need forced induction to run. Check out the wilksh automotive engine as an example that has been under development for a while. An rv-9 has flown with this engine.

     

     

  9. Here's a thought. The Wx Balloon Data was based at Perth AP so more or less sea level (not sure exactly) however I was flying 130kms East at Aerodrome Elevation of 1000' so when looking at the data and relating it to say my AP level of 1000' would the 0 altitude on the data graph still relate to me or would it be the 1000' line which is the elevation of where I was flying at the time. Certainly the ground temperature at the airfield was nearer the 17C mark as shown at 0 Graph Altitude.

    This is not really an easy question to answer however it is very likely that the temperature profile in atmosphere early in the morning has more to do with proximity to the surface than the absolute altitude. Ie would would probably find that the general shape was similar. What is important is the rate of change with altitude, if the air temperature drops by more than 3 degrees for every 1000 foot gained it will be unstable. If doesn't matter is it is 25 or 15 degrees.

     

     

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  10. A good explanation is in one of the classic gliding texts (eg Meterology for Glider pilots by Wallington or the one by Reichman but the exact name escapes me) but my explanation is:

     

    There are a few concepts to understand:

     

    1. Air that is less dense than air around it will rise. This is the well known phrase "hot air rises" expanded a bit to take into account humidity.
       
       
    2. Air doesn't mix very well with the air around it. That is a pocket of hot (or cold) air will stay together as a "clump", it does not become the same temperature as the air around it for a long time.
       
       
    3. When you compress air it gets hotter, and when you lower its pressure its temperature gets colder. The pressure in the atmosphere changes at a reasonably well known rate. The pressure change equivalent to a change of height of 1000 feet is 3 degrees at the heights we typically fly.
       
       
    4. Something is stable if it returns to its previous condition after a disturbance. If there is nothing returning the thing to its original condition it is unstable.
       
       

     

     

    Now imagine that you had the power to just move bits of the atmosphere around at your will. Imagine that you could take a chunk of the air from the surface at the time and location that the trace was taken and move it up to 1000 feet. The air temperature at the surface in that trace is 17 degrees. Now in raising by 1000 feet the temperature of that parcel of air will drop by 3 degrees to 14 degrees. But in looking at the trace the temperature of the surrounding air is 12.5 degrees at this level. So this parcel is now hotter than the surrounding air and so it will continue rising. At this level in the atmosphere the air is unstable. If it is disturbed and moves upwards then is will continue to rise. The reverse is also true. A parcel of air at 1000 feet is 12.5 degrees. If it somehow is moved to the surface it will gain 3 degrees because it is compressed. It will now be 15.5 degrees. But the air at the surface is 17 degrees and so the parcel of air being moved down is colder than the air around it and so it is more dense and wants to sink to the bottom. We have looked at it over a 1000 differential, but it happen over a smaller scale and that starts off the process. A little bit of wind over the surface and something will rise a little bit and then because it is less dense than its surrounds it will keep going.

     

    The unstable atmosphere (having a temperature reduction greater than 3 degrees per 1000) will be constantly trying to resolve the buoyancy imbalance constantly inverting itself. It will be turbulent and bumpy. Often it will lead to thunderstorms if it is unstable to a high height.

     

    What is interesting in the trace you posted is that is is capped by an inversion. Imagine doing the same thing but taking the parcel of air from 1200 feet up to 2200 feet. The air, when at 1200 feet would be 12.5 degrees, but when raised up to 2200 feet with have cooled to 9.5 degrees. On the day you posted the trace for the surrounding air at this height is 16 degrees. The parcel we have moved up is now colder that the surrounding air and it will settle back down to original height. In reality when the air is in this condition there is very little vertical movement and the flying is smooth.

     

    The dark green lines on the trace represent a reduction of 3 degrees per 1000 feet increase in height. Where the ambient temperature reduces by more than this ( ie the blue line is flatter than the dark green lines) then the air will be unstable and the flying bumpy. The graph shows this was the case below about 1300 and this aligns well with what you experienced.

     

    Moisture (cloud formation) complicates things a bit.....

     

     

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  11. If there is a chance that the report could land you in trouble, why take that chance?

    This is where GA does it right. In Australia there is theATSB ASRS

    Aviation Self Reporting Scheme

     

    and in the USA NASA ASRS

     

    ASRS - Aviation Safety Reporting System

     

    Broadly, these schemes allow someone to avoid prosecution if they report the incident. The view is that better data to prevent future accidents is better than punishing past accidents.... Not sure if RAAus has something similar.

     

     

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  12. I have downloaded the version of Solidworks that the EAA membership allows you to have. I think that this is the basic version without the FEA but seems very powerful. It works a bit differently to other CAD packages and so it is a bit of a steep learning curve. Will come in handy for quite a few projects.

     

     

  13. I actually think that this announcement is bigger news than you guys give it credit for. For a start the review isnt being undertaken by CASA but by the "Bureau of Infrastructure, Transport and Regional Economics." The other part that is interesting is that "Mr Chester will also ask the General Aviation Action Group, formerly a subgroup of the Aviation Industry Consultative Council, to report directly to him in future." This gives the industry and pilots the opportunity to ta;l directly to the minister who can hopefully get CASA back into line.

     

     

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  14. Some good new perhaps. It seems that CASA have been pushed into reviewing the medical requirements for Private pilots.

     

    Industry Action forces Progress on Class 2 Medical Reform - Australian Flying

     

    http://www.theaustralian.com.au/business/aviation/general-aviation-review-may-pull-sector-out-of-dive/news-story/5567e3e4d9dfc094d2cb12dbf0d0aeaa

     

    The above link way require that you subscribe. If so just click the link below and then the article.

     

    the australian general aviation review - Google Search

     

     

  15. In a similar vein RAAus say our ident should be for example thirty six, forty four, whereas I laways say three, six, four, four. I have never been queried by centre about this and I am not sure who made up the RAAus method and when. I am sure my method is safer than RAAuss and easier to interpret.

    I will have to dig out the reference but i think that the numbers as groups of two is the preferred way of giving a long rego in the USA.

     

     

  16. Working out the total cost of a kit is hard to do as many kits don't include everything. The things that they leave out are very dependant on personal preference. For instance one person may be happy with a minimalist interior while anther want full leather with carpet floors and side panel. This can easily cost a few thousand dollars to be well done. One person is happy with a mechanical altimeter, handheld radio and ASI with an ipad backup. Another wants a full dual screen G3x system with transponder and engine monitoring, in which case allow $15k and up. It also depends on how you want to do things like wiring. Aircraft grade tefzel wiring can cost a fir bit hen it is all added up, pvc coated is a lot cheaper and works just as well until it doesn't.

     

    One way to get some idea it to look at the cost of the RV-12. Vans supply a full kit including just about everything. For instance there are a lot of parts that you need to install an engine beyond what rotax give you. Each of these is not that expensive but they all add up. You can look at the parts list in the vans FWF kit and they get an idea of what all the extra parts will cost.

     

     

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  17. The issue is partly to do with the location of the Airpark. Before it was built you could have the crowd line at the northern end of the aircraft parking just south of the taxiway. The display axis would then be parallel to this to the north. Unfortunately this is directly over the new houses. The only option is to move the crown line south to the south side of the aircraft parking and, while the show is on, restrict people from going into this area. The map below should make it clear.

     

    )/@-32.219439,148.2277101,2008m/data=!3m1!1e3!4m5!3m4!1s0x6b058312b152f6db:0x851a53a507dd6c9f!8m2!3d-32.216!4d148.2247

     

     

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