On 13/04/2011, at 18:28 , stephenk wrote: > A tug upset from too low would mean the tug pilot had a lot of forward stick > and at release would pitch down. Scary but controllable. I have never heard > of an upset like this (I imagine it could happen, just doesn't seem to). I am > also guessing there is some assymetry which prevents equivalent high/low > upsets (ie power of the glider elevator might be stronger pushing down on > the glider = pulling up on the tug than the perhaps weaker effect of glider > elevator lifting to pull the tug tail down). >
probably because the upset happens slower and is more frightening to the glider pilot, so they release earlier. I've had a number of situations where being in low tow was much more dangerous to the glider pilot than high tow. Behind a low powered tug in a ballasted glider - the tug decides he wants to climb out at 50 knots, not the 75 really want, and hits the house thermal at the end of the strip, then pulls back in it - I have no where to go except down, and initially with zero aileron control. Releasing here will result in a crash, so I hope the tug has enough forward elevator to get back down to me as I have no way of getting up to it. This has happened to be 3 times, and each time I was in high tow to begin with - had I been in low tow, I may not be here now !!! I've flown a vintage glider on a short rope - it simply didn't have enough forward elevator to maintain low tow at the slowest speed the tug could manage. Trying to stay there would probably have resulted in an uncontrolled transition to high tow and then beyond - so low tow would have caused the too high upset. I've flown a glider with a C of G hook and had the canopy scratched by the rope rubbing against it in low tow - which results in reduced visibility in flight. Ignoring the future safety implications, any "normal" mode of flight that causes damage to either the tug or glider is wrong, and should really be reported. At the end of the day, the most important factor is the safety of BOTH the glider AND the tug, not one or the other, and I will make a decision based on the situation, but with a default assumption of low tow. If the tug pilot is unhappy that I want high, he can refuse to tow me. In the situations above, a short rope if either a major cause of the problem, or makes it worse. If I'm presented with a short rope, expect me in high tow. In any situation, a C of G hook and a short rope is asking for trouble _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
