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Geoff_H

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Everything posted by Geoff_H

  1. Without a pitch change my thoughts are on something else in the engine or airframe that is vibrating at it's natural frequency when an engine frequency is near that frequency. When they dug a tunnel under my house I mapped the vibration and amplitude when the machine approached 50 metres down in sandstone. I found that the house had a natural frequency of approximately 50 hz, the tunnel boring machine actually only had very small amplitudes at this frequency. You may have something similar, maybe air ductwork or a panel. To find this you would have to put your hand on various parts and see what moves. Difficult around the Engine I admit. By the way this is only a wild guess, don't spend too much time or money on it. Geoff
  2. Does the pitch of the vibration change with Engine speed?
  3. The cause could be plaque. Only shows up on calcium score. All other tests do not show it. What causes it in low risk people I don't know but a bit breaks off, into your heart and stops the valves from working. Not so nice.
  4. If you are fit and healthy and want to know your risk of dropping dead get a calcium score. I am no cardiologist but mine tells me it is an indication of how much plaque that you have in your arteries that may break off and go into your heart and block it. Stress tests will also help to a lesser extent if they ultrasound your heart under stress. But don't rely on me, I am an amateur.
  5. Maybe you should see a certified, the one that you would use maybe. Ask him/her then make your decision. I just think that if the experience for you is not the building, then don't.
  6. I must admit my clash with CASA was around 2000, many things may have changed since then.
  7. As an aside the advertisement that I placed for making moulds should have read "person needed to make aircraft moulds. At your place" and so on. Advertiser printed "person needed to make aircraft. Moulds at your place" and so on. What a difference a full stop placement meant. No wonder CASA called and threatened.
  8. Yes KRviator it is 51%. I had better pay attention to the details. Some one may have built only 50% and had their aircraft rejected. Personally if one doesn't do as much as possible they would probably be better buying a built aircraft.
  9. When you build an aircraft, even fast build kits, you will put at least 500+ hours into it. At $30/hr that would add $15k, and make something like a onex cost $90k. Might as well buy a factory made craft
  10. I have no idea how CASA handle the sale of a partially built aircraft, the did have a group monitoring the amateur building, maybe not any more. In the 70's there were a lot a accidents, world wide, from home built that were not registered, that's when they introduced experimental class. Our was a carbon copy of theirs some 20 years later
  11. CASA told me it had to be me. They were quite annoyed that I was advertising for someone to do some work.
  12. You should keep a log of your building. You could invent entries, but also expect inspections along the way. Answering intelligent questions to the inspector could be difficult and give you away
  13. It has to be you. The specifications for experimental are for aircraft development or the learning of the builder. In the 70's it was stated that with the rules of the day the Wright brothers would never have been allowed to fly their aircraft. I was building a moulded aircraft some years ago. I advertised for someone to build the moulds. The publisher of the advertisement left a full stop out of the advertisement and it read like I wanted to get someone to build the aircraft for me. CASA called to tell me that it had to be 50% by me. As an aside no one answered the advertisement and I gave up. Maybe you could make a group of people, make the aircraft and do little, but make the paperwork look like you contributed an equal share, might work. But look at the fun that you would be missing out on.
  14. To be in the vh experimental class you must build 50% yourself
  15. Yes.i did it on a vh licence. Unsure what other restrictions are.
  16. The RAAF give you an authorization number. When requesting clearance to enter military CTA you will have to quote this clearance if your aircraft is not based at the aerodrome. If just passing through restricted zone civilian traffic controller will organise it
  17. Hi Callahan, I am 69, about to be 70. Have you checked the vibration damper in the gearbox input? Geoff
  18. Hi Nev, The aircraft is single seat. 12 ft long, 16ft wingspan. Cramped as can be, looks a little like a coffin at present (LOL)
  19. Thanks. I didn't realize that gliders use sidesticks as the pilot is recumbent. I can calculate all the forces and moments etc, I can't open any of the NASA cr1975 documents, do they contain any ergonomic data? Any glider pilots that can tell me what makes a good system and bad system, do any of them wish that they had a joystick?
  20. I am at that point in the design and construction of my little aircraft that I must commit to either a side stick or a joy stick. I have never flown an aircraft with a sidestick. Has anyone here done that? I read a report on the Sirrus 22 that said that the sidestick was the cause of accidents as it used springs for pilot feedback nor aerodynamic force. The sidestick has less movement and hence must have a different feel to it. Also the problem/advantage with a sidestick is that the pilot can be recumbent and hence present a smaller frontal area, but lying down more pushes the CofG back, not nice, I would have to compensate by moving engines forward, possible but adds to the weight.With a joystick recumbent is not possible as you have to reach the joystick between your legs (shh). Any thoughts or suggestions Geoff
  21. Loved them. Especially the rocket near the bum design, must try that
  22. Imagine the research needed to develop a good, and safe, control system. Love the fact that someone is trying, what aviation is best at doing.
  23. In WWII pilots we're trained at Temora with one hour in the classroom and then one hour of physical fitness followed by daily flying. These were you guys! In my late 20's I would do one hour of flying per day after 8 hours of work, that maxed me out. Now nearly 70 I would be lucky to learn at a max of 1 hour per day. I guess it's a matter of how much you learn in a day, any extra flying is just wasted money
  24. Have you checked out the condition of the vibration absorber's in the gearbox?
  25. In a 2 stroke miss. Can be due to gummed up rings. Usually at higher loads, not sure that gummed up rings is the problem, usually occurs after a long period of not being used
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