Geoff_H

I once read an article and if my memory serves me right, it was about CA retractable Cherokee. The author said that the extra weight of retractable reduced speed of the aircraft, the lack of drag increased the speed. It was claimed that it only gained 5knots. Hardly worth the expense. I expect that the extra weight would push the landing speed above the minimum. The aircraft seems to be risky to purchase. Iay have to remove the retractable.

How is stall speed of a modified RAA project determined? Using manufacturers data and calculations of weight effect on stall speed or by observing on landing? Looking at a project that can be expected to have a weight increase based on modification. But not sure it will have stall speed above RAA max

I found another partly finished project for sale. It is the right weight and landing speed but has retractable undercarriage. I thought that this was not allowed in Recreational aircraft. Am I right?

I await your advice on availability, let me know. I will suspend my research. Cheers PS I still have not found a property to store my current project

Skippy you don't seem too keen to sell. Maybe you will do it yourself! When lockdown is finished I will contact you to see if you are still selling. If so I will go to the Oaks.

What constitutes a tyre kicker? Someone that looks but doesn't buy? I once bought an aircraft on first sight. A stupid purchase. These days I do much more research. Seen quite a few aircraft, only bought one. Sometimes one does research by seeing what is available and prices until a real bargain is discovered or that special aircraft is found.

I could not agree more. I love building and fixing things far more than flying. I am a career engineer. I was 14 when I found out what an engineer was, that was the moment I knew I was going to be. Even in retirement I still love being an engineer.

At the end of the day I feel that it is a risk vs benefit issue

Has its SIDS been done? I overhauled an engine a few years ago, I did most of the grunt work under the direct supervision of a LAME. Cost me $40k! After you have an aircraft restored you have spent a fortune or spent thousands of hours and what do you have? Often a very out of date aircraft or a patched aircraft that is hard to resell. What if you bought an old or damaged aircraft and soon after getting it you realise that it is just not worth it, now you have to get rid of a large amount of sheet aluminium and steel or composite junk. Not a cheap exercise. The engine and instrumentation can have value, but you have to find someone that wants it. I think that before purchase a significant amount of investigation and analysis. Not simple. I would prefer to look at the major project killer items before I go look at the aircraft.

I have been researching the aircraft for a while. Two problems, is it repairable with moulds and where could I store and where could I repair aircraft. Limited workshop space, completed aircraft will not fit in my garage. Started researching a few weeks before covid lockdown, about to go to the Oaks for research. Then lockdown. I will resume after lockdown. No point trying to remotely solve issues.

I am interested. Not knowing what instruments etc that could be sold of it ends up impossible to be fixed.

The way that I remember it is that the restoration of Muja was proposed by Kempe in an attempt to make a fortune. The result was dismal. Similar to Transfield and Collinsville.

I was contracted to Kempe for design services. I had previously worked on the restoration of Collinsville where we had problems with boiler leaks due to rust under lagging throat had sat in the cold elements for years. I mentioned that to Kempe, they told me that that had checked for corrosion and shut me down. Then they had the steam pipe rust failure. Not a site I was going to work in. However I had the Mooney then and could have flown in and out from time to time, however got consulting contract with a Sydney Water job, a water turbine generator the a BHP contract and didn't want anything else to do with it.

Current electricity generators are very frightened of investing huge money in a power station only to have it stopped and the money lost. Take Redbank Power station. Killed by Labor government. If Liddell was shut down today the price of electricity would increase and it's present owner would make more money. Liddell was first commissioned in 1971 with a design life of 20 years. In 1988 a study did woyon what was required to extend the life to 2000. How it still operates I don't know. I know its output is severely reduced. They really don't care how energy is generated, they just want to be doing it. There is huge money in electricity. In the 1990's Yalourn power was sold for a very large amount of money, the new English owners found that they were sold a pup, not nearly enough return on investment. On learning how much the Victorian government got for power station sale every other government wanted to sell their power stations. However there were no buyers as the buyers realised that there was not the profit in it. In NSW the government decided to make the power stations much more profitable. So renewing Poles an Wires was introduced. Substations the didn't have a power supply was built and power stations now had heaps of potential expansion installed and a huge increase in price of electricity from poles and wire increases. We essentially pay a tax for the money that the government got for the sale. They built a few gas turbine stations, none combined cycle (much better efficiency and less emissions per kWh) cheap and profit making. A few years ago the bulk price of electricity averaged out at $140/MWh, $0.14/kWh, I pay a lot more than that for retail power, nice little earner. Some gas turbines are installed and don't get used until the price of electricity goes high (one I know does not operate until the price goes above $6,000/MWh). After all a gas turbine can go from Zero to full load in 10 minutes. During the recent Queensland power failure the loss on power was made up by gas turbines just sitting and waiting for such a price rise. It went so high that a in 5hours the profit amounted to 10% of the gas turbine purchase price.

It pays to thbe green and know that black lives matter if you are going to be allowed to mine the community assets. I have knowledge of these situations but cannot supply information as I am bound by confidentiality agreements from when I was actively consulting. Hey I reckon that we should go renewable for several reasons, one being emissions another saving of critical assets for future generations. I just don't think that we are going in the right direction.

Not an untruth, but the situation could be misconstrued from what is written. I am fully in favour of renewable energy. But without a planned transfer and analysis of the situation we will see blackouts before too long. The attached file shows what happened in the recent Queensland failure. Gas came to the rescue. As older coal generators give up the ghost we will have little or no backup to cover failures. x1.png.pagespeed.ic.0VmDUTsi93.webp

I have worked on the Newman installation. What you read is half the truth. How is the mine powered? There used to be 3 GTs. I worked on one.

Wind generator costs about. 1.5M/MW. Gas turbines similar price. Diesel engines much cheaper. But you still need full capacity for when the wind does not blow. So wind capital costs are twice plus outback installation costs which could be extremely expensive...I have worked on outback mines they are expensive. Truck driver gets $200k+a year. So wind costs $90M+ extra, 6W typical load

Just one item on a wind generator is a crane to assemble it. I don't know if you have ever ordered a large crane but they are mega expensive. And take as long time to get into the outback. Cells produce rated output at 20deg junction temperature. You are getting a nice output at the moment. What is the outside temperature where you are? Cells are specified with a degredation rate as junction temperature rises. It gets very hot from electrical resistance while generating. I have often thought of using Peltier effect devices to cool the junction and increase the output, around double the rated output in summer. Same could work for decreasing charging time of ev's

Output

It's the max panel put

Most of what you read about renewable resources on the internet is published by persons or companies with a agenda. The greatest con is to quote MW not MWh. Every now and then I do a sanity check on the figures few rarely give statements that are honest

They were looking at 3 to 5 MW. He is a Greenie but is also a very capable engineer. He told me that he couldn't get one sold on economic grounds. 4 times the cost of running gas turbines and diesel engines.

What put are you getting in winter?

I have time of use metering. I have significantly cut my electricity bill by scheduling things like the pool in the middle of the night all washing and drying eccetera is done before 14 in the afternoon my underfloor ventilation system only works at the cheap time. Another problem I have is that my roofs face East West so panels would stick up at a funny angle who the roof. Just about every calculation I have done as shown that the return on the investment is not that great I would love to disconnect totally from the grid but the cost of batteries was astronomical. I did a lot of work with organic Rankine cycle generators that just use panels getting heat like hot water heat off your roof. It would use hot water tanks for heat storage. The efficiency was so low that I would need some 80 panels in the backyard to give me freedom from the grid. Still looking. I just replaced my roof the old one leaked too much. The replacement roof cost me $20,000 I investigated getting Tesla like PV tiles in my roof. Quote came back at $70,000 with 5 kw of panels, not quite sure if the 5k was actual or nominal but either way its not economic.