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#41
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Todd Pattist wrote:
For high performance gliders I'm surprised no one has mentioned that the installation of gyro instruments is prohibited in competitions. That's why our gyros are installed with nuts with a small hole in them, so you can cover the iinstrument with a piece of cardboard and seal it. Stefan |
#42
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Todd Pattist wrote:
Training gliders are for training, and no one gives instrument training in gliders that I'm aware of. Well, we've got a T&B in our Blanik, and if I can get the thing on power, I plan to do at least the lifesaving IMC training in it... At least a few glider pilots have told me they've landed after dark too, in the horizonless desert. I myself have been in horizonless smoke (thankfully in a glider with a T&B). I've been in that same glider (briefly) disoriented in craggy mountains, solved by a glance at the T&B. I suspect there's a bit of "too expensive" and "if it's installed they'll be tempted to use it" in there too. That said, I've seen them in rental 2-32's and a club Blanik, but they don't seem to be common. The "tempted to use it" comment is apt. Despite warnings not to practice emergency procedures solo, and signing a form to that effect, I've had pre-license (power) students fly solo IMC and do spins on their own. There's no substitute for (bad) judgement... For high performance gliders I'm surprised no one has mentioned that the installation of gyro instruments is prohibited in competitions. Last I looked, you couldn't even install a Cook or Bohli compass. That these gliders then regularly don't have this equipment is unfortunate. Is the rule really "can't be in the aircraft" or is it "can't be operational?" One would hope the latter is sufficient. Panel space was an issue, and I suppose there is some current draw. And I'd expect it might be hard to find an A&P (mechamic) to install one on a switch More good points. If I flew at all regularly in wave, I'd seriously consider installing a T&B, but my glider is experimental, so I can do what I like.. From a private e-mail, one sender mentioned neither the rental 103 nor Discus he flew in Minden had T&Bs... I want to point out to those who perhaps are considering installing a gyro in their glider, that a Turn and Bank and a Turn Co-ordinator are two (slightly) different things. A T&B has a gyro on a plane so it only gives rate of turn information AND IS MUCH LESS SUSCEPTIBLE TO TURBULENCE. The TC has the gyro slightly canted so it gets a tiny bit of roll information displayed too. Although the TC is easier to use for inexperienced IMC pilots (because it acts a tiny bit like a AI), it is much less useful in tubulence, which is often when it is most critically needed. I'm not at all a fan of a TC. Be careful when buying something too, because modern instrument makers put mixed displays on the gyros. If it looks like a TC (little airplane wings) it might not be, and if it has a little needle and doghouses, it might not be a T&B. I'd be careful at initial purchase to make sure what I got, and then get an old hand to test fly it for you and make sure it doesn't move on the initial roll-in or during dutch rolls... As far as current draw, that's another thing I can't speak to. Ultimately I suppose whether one installs a T&B is an individual decision... Todd Pattist - "WH" Ventus C (Remove DONTSPAMME from address to email reply.) -- ------------+ Mark J. Boyd |
#43
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Ian Strachan wrote:
This sort of training is less sophisticated than that conducted in professional aviation, but is effective in a sport aviation environment. IMHO. Others have made the point that above 8/8 there is no substitute to having at least one gyro instrument. Even the humble turn and slip instrument will do! It's cheap, cheerful and works safely with little battery power. I'm glad to hear you folks over there do this. And I bet you have few IMC related accidents, eh? -- ------------+ Mark J. Boyd |
#44
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In article 418cee9a$1@darkstar, Mark James Boyd
writes snip I want to point out to those who perhaps are considering installing a gyro in their glider, that a Turn and Bank and a Turn Co-ordinator are two (slightly) different things. A T&B has a gyro on a plane so it only gives rate of turn information As I understand it, some of your US turn-gyro instruments have a panel presentation from the turn-gyro not with a needle but with an aircraft. I have seen these and think that they are seriously misleading, particularly for the inexperienced instrument pilot. What I mean is that they can mislead the pilot into thinking that he is getting angle-of-bank information from the instrument when he is in fact getting rate-of-turn from the standard Sperry 1920s design of spring-constrained rate-gyro system. As I said in an earlier posting, this was a simple and breakthrough system for retaining control in cloud, but the rate gyro is just that, a measure of rate of change of direction. More precisely, direction in the plane at right angles to the basic spin direction of the gyro. In my recollection, turn gyro instruments are set up in the lab so that a rate 1 turn takes 2 minutes to go through 360 degrees. If my recollection is right, a rate 1 turn gives a 180 heading reversal in one minute. On "limited panel" we used to practice these as so-called "pattern turns". AND IS MUCH LESS SUSCEPTIBLE TO TURBULENCE. Compared to what, and why?? The TC has the gyro slightly canted so it gets a tiny bit of roll information displayed too. You will have to explain this, I do not understand. Rate-of-Turn is related to steady bank angle, of course, but these are not quite the same, particularly in turbulence or when recovering from "unusual positions". A simple Sperry-type rate-gyro instrument gives an output in rate-of-turn whether it is by a needle (rate 1, 2, 3 etc) or a (misleading) aircraft silhouette. The gyro spin is in the direction of the longitudinal axis of the aircraft. Also the gyro could be made to spin in either one way or the other (clockwise or anti-clock, of you like). In an aircraft turn instrument, the gyro is designed to spin in the direction so that application of "G" increases the needle indication rather than decreases it (the so-called G-error for turn indicators). The consequence is that if you wire up the DC to your turn indicator the wrong way, the gyro also rotates in the wrong way and you lose its sensitivity under G. Such as in a spiral dive when you could pull the wings off because as you pull the needle moves to the middle and you think that the wings are nearly level, and so pull harder. But they ain't anywhere near level, just think about it ...... So, fit a turn gyro instrument and make double-sure that the DC is wired the way it was intended. Test it by flying in VMC with the gyro on, make a steady rate 1 turn and then pull a little G. Make sure that the needle deflects further, not goes towards the middle. This could save your life if you ever get in an inadvertent spiral in cloud. -- Ian Strachan Ex military Instrument Rating Examiner Lasham Gliding Centre, UK |
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