Firstly, MOSP 2 Section 23.4 states that reflex launching is no longer considered a satisfactory launch method and permission for such launching may not be granted.
As I recall the rope we used was 12mm ployprop that had a stretch of around 1.4 times. The problem with his type of launch, apart from the nose high attitude at the start and low speed as Terry describes, gliders that sit on the nose skid need to have the tail held down to prevent the tail skid banging hard into the ground. The car we used was a short wheel base Toyota 4WD. The rope was snaked out at the glider end and the car started near the glider. The car was driven to 80kph and the rope hissed as it was dragged out. Once the rope was tight, the glider was launched immediately into the air with no ground run. I did a few launches in both a K13 and Zephyrus. With both the tail skid hit the ground with great force and the glider was airborne. We eventually managed to have someone hold the tail of the K13 down but you couldn't do this for Zephyrus. One had to closely monitor the speed and ensure you released if it got below safe. It seemed to take an eternity for the "power to come on. I would not like to do one of these launches in a slippery machine. It should also be pointed out that this method was being trialled, not as a normal method of launching, but so that a glider could be launched off a beach to slope soar the sand dunes down Anglesea way. Terry can tell you how successful this venture was! Chris -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, 25 November 2009 9:05 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] Reflex car launching Hi Ron, we did some reflex launching at Bacchus a while back (10-15 years?) and it was good fun. We used aerotow rope, approx 1000 feet if my memory is correct - the stretch meant that you could actually get (slightly) greater altitude than that. I can't remember the car speed as it took off down the runway, but 60-70kph sound familiar. You'll just have to try that one. The speed was certainly a lot less than people think it needs to be. The really exciting part is after you leave the ground and due to the reduction in drag the rope starts to shrink (un-stretch) which gives you the same feeling as a cable break or loss of power with a winch lanch. If you keep the nose down the rope continues to shrink and you have a major problem, so the solution is to trust in some greater being and just keep pulling back and hope that the rope really hasn't broken - not a good feeling and goes against all of your training. If you pull back the rope (eventually) goes tight again and you have a lovely launch. We did it for a while but then fear took over and we resorted to normal auto tow, with heights achieved not much less than the reflex. Terry On Wed, Nov 25th, 2009 at 12:07 AM, Ron Sanders <[email protected]> wrote: > Does anybody remember the old "reflex launch" I am not sure if it > was > ever legal but at Cunderdin I can remember sitting in a Kooka and > upon > the ready advice the car took off straight down the runway at full > bore with no uptake of the slack or anything---the shock was > absorbed > by a flexible (nylon??) rope section which somewhat later after its > rapid extension would give back all that energy after which you then > did a "normal" auto tow. I am after approximate lengths of rope and > stretch part that people might have used in those days if anyone > remembers. > > Might do it again for a laugh one day!!!!!! > > Ron > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
