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Geoff_H

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Everything posted by Geoff_H

  1. I used to like the ADF to get the cricket when crossing the nulabor ? Shame that they closed them down, well maybe not. I used to hate night flying on an ADF, VOR was much easier. Geoff
  2. A GNS430 has a VOR tuner in it. Independent of the GPS section. I had a GNS 430 and it had a faulty tuner. I had to upgrade to WAAS to get it fixed. Cost me a fortune. Geoff
  3. Some 20 years ago I had an experience with "shotgun Sally" at Bankstown. I can't remember why, but I was entering the area from.a non standard approach. Then decided to fly to the standard approach point and report on arrival to that point. Well I accidentally called over the transmission of another aircraft. I thought that the controller, shotgun Sally, was calling me, she talked so quickly all that I could understand was the ending of her transmission was "qubeck", I was flying an aircraft that had a call sign ending in"qubeck". Well that slowed her rapid aircraft handing right down, did she give me a dressing down over the air. I was ever so cautious at that point. She gave me instructions to fly for a centre runway landing. In the following short time she must have changed the instruction to the left runway. I was certainly not answering any call that I was not sure of, so I never sent a confirmation reply. As I was on final descent I noticed a twin lining up on centre, I was confused and reluctant to report it owing to my earlier dressing down. The I got a very distinct instruction " clear to land on Left". I reported that I was on centre and given immediate go round. Things went normally after that. Some ATC official called me on my way home and said that they would be reporting me! Well after I replied to CASA with a written report saying that Shotgun Sally was difficult to understand and what had happened I never heard another thing. Not even that the issue was resolved or dropped. I avoided Bankstown like the plague after that. Geoff
  4. Words You Should Not Use copied from the latest Mooney magazine “For” and “To” sound exactly like “four” and “two”. Used in the right combination of numbers, these words can be confusing and lead to miscommunication. Here’s an example: “Center, Mooney 257KW climbing to one thousand.” You can see how this can be miscommunicated as 21,000 feet. How about Mooney 257KW descending for 5000 (45,000 feet?). Instead, try to keep it simple, concise and understandable. “Denver Center, Mooney 257KW, four thousand two hundred, climbing one zero thousand."
  5. Parachute canopy that is.
  6. How does the manufacturer ensure the 20deg nose down. Are they 2 connections to the canopy or 3?
  7. Does anyone have a parachute installation on the aircraft? If so what is its deployment method? Has anyone ever been in an aircraft where a aircraft parachute has been deployed? What do I do if there is a problem with the attachment position in an aircraft where the CofG is close to everything, or where do you place the connection?
  8. The reliability and security of an engineering design is given a rigorous design review of which the probability of failure is a part. First we look at the consequences of failure of the piece of equipment. We assign a failure consequences number. A consequence of minor nuisance gets a small number, many deaths and large financial cost the most. Just large financial costs gets a high number! Then each subsystem gets analysed by a team of independent experts and analysed for failure in a dedicated set of ways, over/ under temperature, load, height (tanks etc) and so on, including any other failure. Then each failure system is analysed for ways of preventing the failure, the corrective action. If it is human intervention the probability is 0.5 of failure. If the failure is owing to an equipment failure then maintenance, replacement within failure times, and replacement are looked at to mitigate the impact of the failure. This is a quick, and lacks some details in trying to keep it brief. When it came to a separation of the moving parts of a gas turbine, we used to say it was contained within the casing until the Qantas A380 engine incident. We don't always get things safer with this system, but it is far safer than no system.
  9. Thanks "emu" you have clarified the science better than I ever could. I am at the bottom end of the spectrum so I am not so good at explaining things.
  10. I find it very interesting, fun and not so difficult. I have retired now but still dabble.
  11. When you are determining the safety of a system for controlling some piece of apparatus you have to look at each part of that system and them calculate the probability big failure. Should the probability be low then a physical inspection of the system is required at a frequency that is significantly shorter than the failure probability. If for example you have a control system that keeps the altitude constant and uses a human that can only see an altimeter, nothing from outside then you have to put 0.5 as the probability of his failure. If an electronic control system is used to keep the altitude then the system usually calculates a fairly low probability of failure. So an inspection/testing regime will be developed. Hopefully an inspection is calculated to be greater than 100hours. I did a lot of work with TMR (tri modular redundant) system uses three computers checking each other and all three must agree to execute a control function. These systems of have a reliability of one failure every million operating hours. I designed these systems for gas turbines.
  12. It's what the requirements are for failure probability. I tend to agree with it. It's about a decision required to stop a catastrophic result. It's an Australian standards thing.
  13. During my career I did a lot of failure probably studies. The surprise to me was that if a human was responsible for preventing a failure then the failure probability of the human was 0.5, limit switches were 0.0001. in other words a human is the weak link, making a wrong decision every second time.
  14. My project has two engines. Each can have two spark plugs, I have chosen a single on each engine to keep the weight down.
  15. Sure that both mags on a single drive has less reliability. But the loss of reliability is so low that it's minor. Mooney's J series have Lycoming engines in this configuration. You can get a dual conversion kit, if one gear goes, it will probably destroy that drive and all drives will be cactus. How many Mooney's have come down owing to the mags? None that I have known, I elected to overhaul the existing one. If you want to increase the reliability of your aircraft with such little increment in reliability buy a twin.
  16. I use carbon infused nylon. It's specific density is a little over 1. The parts have to be redesigned to take advantage of nylon/carbon features. Steel .050 inch can be replaced with 0.250 inch nylon/carbon with a honeycomb centre of 30%,-40%. What really has to happen is that every printed part has to be re-engineered to seeing it can be replaced.
  17. I have been experimenting with 3d printed load parts to replace steel parts
  18. A single seat twin. A little similar to a cri cri
  19. My project
  20. Methane gas in reciprocating combustion engines have another problem. For a given cubic capacity and compression ratio the brake horsepower is significantly lower. As the flame velocity is quite low pre-ignition is not a usual problem. Hydrogen on the other hand has a flame velocity 10 times that of methane. Hydrogen makes a better bomb lol.
  21. Maybe you are right. Should I leave the underwing engines out.?
  22. I have been building my own design for 5 years now. I have come to the conclusion that I am stupid ?
  23. Using solar to make hydrogen from water using solar is good. It just needs an excessive amount of solar cells. One solar sell on a sunny day will produce enough energy to drive a Tesla 4km. With the losses of manufacturing hydrogen it would travel significantly less.
  24. It might be cheap before the government pits taxes and excises, and a 3cent for 3 year levy. Bit it is a greenhouse gas so they will add a carbon tax and it will be more expensive than petrol. Lol
  25. My project is not a lot. It is my own design. It is the second aircraft project I have been building over the last 20 years. There was a gap of 7 years when I owned the Mooney and basically worked in WA. However I regret not building at lest someone else's plans. A particular piece of folded light gauge aluminium took me 6 goes to get right.many parts have rebuilt at least once. I love the design part, after all I still regard myself as an engineer albeit a retired one. The maths is fun, the building disappoints me, I am not so great a tradesman. Over 70 so building hours per day significantly down. I try to do a little each day, a lot somedays. My current say home no matter what, covid-19 for over 70's, has me enthused with the wife only demanding some yard work (no shopping) things are happening. Geoff
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