>From 200 feet you could get half a loop in.... JR ----- Original Message ----- From: "Graham Watts" <[EMAIL PROTECTED]> To: "Discussion of issues relating to Soaring in Australia." <aus-soaring@lists.internode.on.net> Sent: Thursday, September 18, 2008 1:06 PM Subject: Re: [Aus-soaring] 180 degree turns - teardrop
> Agree Terry. > > Mike Valentine would have said 'This type of maneuver should always be > watched from a safe distance' > > > > > > Terry Neumann wrote: > > Texler, Michael wrote: > >> To throw the cat amongst the pigeons. > >> > > Thanks Michael, This pigeon admits to being quite alarmed by some > > aspects of these papers =-O . > >> Here are some links with attached research, regarding the best way to do a 180 (if required). > >> Any comments or disagreements? > >> > >> OK, if people want to poo-poo this, please provide a rational and reasoned explanation why (i.e. use a scientific and objective argument). > > I certainly won't poo-poo it, because I'm not strong on scientific and > > reasoned discussions with professors who are clearly expert in their > > field. As Mike says ".....They did the math.". Therefore as an > > exercise on paper it is quite credible. > > > > Unfortunately however, math or not, the history is that a lot of > > people who have attempted this option died in so doing. This > > suggests that whatever the math might say, it's a helluva risky > > manoeuvre which frequently fails to work out as the theory > > suggests. The concept might be plausible, even convincing, but this > > is no consolation if you are in the wreckage, or perhaps worse, if you > > are one of those who is put in the dreadful position of being the > > second or third person on the scene of the accident. (The first > > person BTW is the pilot - the second may be the instructor who was > > demonstrating the exercise). > > > > The difference between theory and practise is often much greater than > > the theory would suggest. IMHO this one such situation. > > > > As for turnbacks at 200 ft? Not if I'm around thank you! Especially > > if I'm on the inside of the aircraft. > > > > The other problem with a theoretical approach to a situation like this > > is that it might indeed be achievable with an above average pilot, but > > a pilot with lesser ability (or experience - probably both) sees it > > done once effectively by the club hotshot, programs himself to > > consider the same option if it happens to him, but when it does, he is > > 50 feet lower, 5 knots slower in speed, about the same number of > > seconds behind what the aircraft is thinking, and a tad excessive with > > the rudder....... You can guess the rest. > > > > It's usually much easier and quicker to derig the aircraft in the next > > paddock than to have to pick up all the pieces on the airfield. > > That's still how I would prefer to approach an event like this. I'm > > not sure if this is sufficiently rational or reasoned, but wreckage on > > the ground has a way of re-evaluating theoretical argument - often > > very dramatically. > > > > Terry > > (With apologies for possibly excessive cynicism, but pigeons can be > > like that if the cat is significant ....) > > > > > >> http://www.nar-associates.com/technical-flying/impossible/possible.html > >> > >> http://jeremy.zawodny.com/flying/turnback.pdf > >> > >> "Conclusions A simplified model of the turnback maneuver after engine failure during the take-off climb segment has been developed. The model shows that optimum conditions for returning to the departure runway result from climbing at Vmax , executing a gliding turn through a 190-220deg heading change, using a 45deg bank angle at 5% above the stall velocity in the turn using a teardrop shaped flight path." > >> > >> P.S. Thanks to Daryl McKay for providing these links. > >> > >> > >> _______________________________________________ > >> 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 > _______________________________________________ > 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
