Having recently been towing when i had a complete engine failure. And the subsequent discussions with the glider pilot (an instructor) he did not see the wing waggle or the tug disappear out of sight. All this occurred very quickly. and he was in low tow. There would be very little chance of a glider pilot recognising a tug problem in high tow and having time to react. This incident can be read about in GCV Airflow available online Mark
Date: Wed, 13 Apr 2011 22:37:10 +0930 From: diob...@gmail.com To: aus-soaring@lists.internode.on.net Subject: Re: [Aus-soaring] Where to sit on tow? Now that makes sense, thanks for the explanation Stephen :) On 13 April 2011 17:58, stephenk <steph...@internode.on.net> wrote: Peter, yes. Mike two posts below described one. The Tasmanian accident, while never officially given a cause, was _very_ strongly suspected of being this type of accident. The older set of UK accidents were like this, I haven't read the new ones, but it would be a fair bet they are too. I'll describe the chain of events again as I am sure Dion is not the only one to misconstrue the situation. As the glider goes higher above normal high (line astern) tow the tail of the tug is pulled up. To counter this the tug pilot applies back stick. Higher glider => more back stick and also greater load on the rope*. Now in this situation if the glider releases or the rope breaks, the tug has the stick a long way back and, despite whatever speed they are doing, the tug pitches up rapidly (ie less than a second) and stalls. If there is any yaw this will cause a flick roll. *Can also get to the point where neither end can release due to too much load on the rope and the mechanical advantage of the release(s) not being enough to get over centre. 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). Regards SWK On 13/04/2011 1:51 PM, Peter F Bradshaw wrote: Are there any reports of tow induced tug stalls? On Wed, 13 Apr 2011, Dion Stuart Baker wrote: It works both ways, of course. If you get too low, you pull the tail down and cause the tug to stall. I'd say a stall is more dangerous than a dive. A dive takes less time and height to recover from. Dion On 13 April 2011 13:11, DMcD<slutsw...@gmail.com> wrote: _______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring -- I am leading a campaign to save innocent trees from destruction. If you wish to print this email, please use criminal trees that deserve to die. _______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
_______________________________________________ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
