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Bruce Tuncks

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Everything posted by Bruce Tuncks

  1. Bruce Tuncks
    Apart from the insurance aspect, I wish you well OME. I'd like to come n say gday, but the insurance is a problem for me too.
  2. Bruce Tuncks
    Me too old K. I have never believed in insurance. Why would they pay me when they could use the money to advertise? When I told too much of this around the club, they made me Insurance Officer. Did I reform the paying? I wish I were more brave, but the club was paying about $50,000 in premiums and collecting about $20,000 a year in claims. all our claims were payed out wonderfully. It would have taken somebody braver than me to bet this pattern would continue.... What if a passenger flight caused a young doctor to become a quadraplegic? So I am no longer any sort of officer and I like that.
  3. Bruce Tuncks
    I like your arguments ARO, but if you are correct then there would be more auto conversion engines in use in planes, maybe an enterprising type will fit one to a kit plane and do it well. In the meantime, I reckon KG has a good argument in that they are different beasts. He didn't even mention the rpm deal. I like my Jabiru with no gearbox, but auto engines run too fast for a direct drive. Yes I know that the Rotax has a gearbox. There was an auto conversion I have seen where a V8 was being used in a Pawnee tug plane. The reduction drive was a short toothed belt and it was destroying itself against a flanged pulley wheel.
  4. Bruce Tuncks
    ARO, your math says that a plane engine has a failure once in a MILLION km, if flown at 100km/hr. I reckon my cars have been less reliable than this.
  5. Bruce Tuncks
    The last cockpit smoke event I have heard of was caused by a Li-Ion battery shorting out internally. I thought that they subsequently banned such batteries.
  6. Bruce Tuncks
    They were on the early spitfires ( float carburettors ) but not the later ones. I like the idea of a simple mechanical injector.... how does it work?
  7. Bruce Tuncks
    There was once an instructor who used to show his confidence in a student by throwing the control stick away . One day a student got a spare stick and pretended to throw his away too. I dunno if the instrutor died of a heart attack or not.
  8. Bruce Tuncks
    A mate of mine was captain of a Fokker Friendship which was flying back from the N of SA with a bunch of miners who had been loaded evenly through the half-full plane. When it had become quite nasty to fly, my mate found that all the miners had congregated to the back of the plane to play 2 up. When he told them to resume their allocated seats, they said to get f#cked. OK, he replied, then we are all going to die. Well this worked.
  9. Bruce Tuncks
    There is a true story that agrees with your comments nev, but I must admit to not really understanding just what was happening. On my Mosquitp glider, the tailplane was fixed with a bolt at the front, and a slight amount of wear could be felt as a "clunk" when the tailplane went from lifting to pushing down. I could make the clunk happen just by flying slow enough, say 45 knots. At this speed, the tailplane transitioned to lifting I think. In the olden days, wings had a "center of pressure" which moved back as speed increased. This was changed to a moment, since it was embarrassing to have a wing where the center of pressure was behind the trailing edge. Getting back to the Mosquito, I finished up putting some foam rubber near the bolt and this stopped the clunk completely.
  10. Bruce Tuncks
    The fuel supply was so uneven that I worked on it to the extent of putting vanes downstream of the carby before I was happy. In my mind, the flow out of the carby was not completely atomised when it entered the inlet manifold. So I deliberately deflected some "droplets" that would have flown past the earlier cylinder offtakes into the no 1 and 2 cylinders.
  11. Bruce Tuncks
    My old falcon didn't have a limp home mode that I knew of, and I had no way to get near 40 psi to pump fuel in. I do see that the uneven supply of fuel to a Jabiru engine can be fixed with an injector. But how do you get redundancy with this?
  12. Bruce Tuncks
    A real annoyance used to be how a battery charger would not work if the battery to be charged was below some voltage. Is that something like what happened with the Diamond? I think newer battery chargers do not have the same limitation..... I think I have seen how they will charge up from zero volts.
  13. Bruce Tuncks
    My strong guess is that the 1" did not change the damping to underdamped or even critical. I wish I knew more, but I would have to have a disposable ballast setup like Harry Schneider used once. ( a bag of sand with an emptying pull-string) to test this out. Sorry, but I only ever heard of one guy who flew like this. He won the championships, but he was pretty good anyway. Would he have won if he had just used the approved figures and bolted lead inside the fin? I think so, but who knows? Incidentally, test flying is very difficult to actually do in practice. I once tried to figure out if turbulators helped a Mosquito glider, and if so, just where to stick them. I had sections of turbulator-tape ahead of pitot tubes connected to a spare vario . I thought that a differential comparator setup would be the most reliable, so there was an identical setup on each wing . Well, I was only after an improvement, not solving unknowns. Well, after several weeks, I gave up! it was all too hard. The wings are NOT identical and I found no position of turbulator tape that improved things (as measured by the pitot tubes ) at all speeds and flap settings.
  14. Bruce Tuncks
    Cars are not completely reliable these days. There we were, me and the missus, on the hume, in our falcon, going past wangaratta when the engine stopped! It was the fuel-pump, which is inside the fuel tank and has a cheap sparking brush-motor. Apparently the atmosphere inside a petrol tank is too rich to ignite, please don't test this with a match. (I since heard of a guy who got home using his model-plane peristaltic cranking fuel-filler pump. He said it was hard work cranking on an upgrade ) The pump works at about 40 psi, the guy who replaced it was impressed that planes had 2 fuel-pumps but he reckoned that most of his customers would ignore the failure of one pump and keep on as usual. When a similar thing happened on my old P76, I got home ok using an air-bed pump to put a few psi into the petrol-tank. I know now that putting oxygen in there is a bad idea. And I reckon there is a lot to be said for the old-fashioned carburettors.
  15. Bruce Tuncks
    We would wear a chute and sit in the glider on scales inside the hangar to get the figures to calculate just how much lead. It never occurred to us to go back behind the aft limit, but the point we all aimed at was that limit. Except for this quite fat mate, who was quite slow in races and we didn't figure out it was the c of g which was hurting him. I realize now that we also could have carried more water-ballast, although it would have been safe but illegal to use "unused" cockpit weight allowance quite safely as water-ballast extra. In the olden days, Libelles had a rough airspeed of 135 knots, and we used to do start-runs at this speed, full of water. Glasflugel had used an old standard in their certifying. The most recent AD was to reduce this to 89 knots or so. But no wings were ever ripped off using the 135 knots idea. Maybe I'm lucky that we didn't use the extra water-ballast, but my guess is that we were just a little slower and the wings were strong enough anyway.
  16. Bruce Tuncks
    Bosi, that sounds ok to me. I think you can measure angle of attack with a spirit-level, but I never tried that. I was really quite happy with the climb performance of the Libelle anyway, but I did move the c of g back.... there is a mounting-point for lead bits just forward of the rudder for this purpose.
  17. Bruce Tuncks
    Never tried any spins in a Libelle. The airbrakes are very effective and it comes down real fast if you open them. I think you can maintain a 45 degree downwards at rough airspeed but I've never tried that either. Gosh what a boring pilot huh. The only real spin I induced in a glider was in a Ventus in Nevada. I was framing a picture of a snow-flecked mountain-top with the camera at the clear-vision panel and framing the pic with the rudders. So I didn't see the ASI or anything else, but that Ventus sure kicked into a spin. ( I was about 17,000 ft at the time, and all alone, so there was no danger at all ) Actually, I reckon height is too hard to get and too easy to lose anyway, especially in a glider. So aerobatics of any sort never appealed.
  18. Bruce Tuncks
    I just read a report about a "battery failure" that caused a twin to crash... there is a real downside to using fuel injection setups which need electrical power to work. I well remember Rod Stiff rejecting the idea on reliability grounds, and this sure proves him right.
  19. Bruce Tuncks
    Well this guy survived ok as well Nev. As I said though, for the reasons you have stated, I personally was law-abiding .
  20. Bruce Tuncks
    I'm sure it was illegal nev, but he sure showed it went well. I wonder if the "certified" CG position is not compromised by "safety" considerations... But, as I said, I was too afraid to find out.
  21. Bruce Tuncks
  22. Bruce Tuncks
    The best Libelle pilot ever ( gosh I'm showing my age here) was asked where he liked the CG.... "an inch behind the aft limit" was his reply.... then his eyes grew big... "Bugger, I forgot to tell those whackers who bought it about the lead in the tail" We also had a glasflugel 304 at the club. This thermalled very well with a light pilot, but very poorly with a heavy one. For Spacey's benefit, the tail loads are usually DOWNWARDS so extra lead there reduces the induced drag... but there is more to it than this, the overall performance is better for some gliders at aft C of G. Personally, I was too scared to go back behind the aft limit, but I well remember Harry Schneider fixing a bag of sand with a string pull-tie to the rear fuse of a new glider they had designed and were certifying. I dunno how far behind the aft limit they had to demonstrate spin recovery at. The string was clearly there to empty the sand out if spin recovery was not happening.
  23. Bruce Tuncks
    Sorry I missed the bit about "already solo".
  24. Bruce Tuncks
    He certainly does not sit in a deck chair with a radio. He teaches stuff like Zulu time and notams and stuff like that.
  25. Bruce Tuncks
    At Adelaide, we had/have an instructor who teaches the theory etc on the ground, and he does a pretty good job I reckon.
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