>>Terry was trying to impress air show crowd by demonstrating the strength and >>flexibility of a modern glider wing. He simply cycled the flap lever very >>rapidly several times and in quick succession.
Without having timecode on the video it is difficult to be certain but he must have been moving the flap lever at about the limits to human muscle speed back there. That's certainly impressive. >>By doing so he deliberately induced a wing flex that is well within the >>capabilities of the aircraft. In other words, NO FLUTTER AT ALL! If it looks like a duck, quacks like a duck.... Maybe it was part of the duck which seemed to fall off the wing and stopped it quacking! D On 05/05/2011, [email protected] <[email protected]> wrote: > Hi Derrek > > I agree, the comment that the glider can be loaded with water ballast > to 1.2 tons appears to be a mistake > on the part of the air show commentator. After fliying with Terry > Delore in this particular ASH 25 I can > confirm that it was not modified to carry more water ballast. > > But more than anything else this episode highlights the dangerous > practice of jumping to conclusions (and > mistaking a deliberately incuced wing flex for flutter) after just a > very superficial observation. > > Terry would never continue with an aerobatic display after > experiencing flutter. He is a very responsible > pilot and didn't set some 20 or so world records without knowing what > he is doing! > > Kind regards to all! > > Bernard > > ----- Original Message ----- > From: "Discussion of issues relating to Soaring in Australia." > @lists.internode.on.net> > To:"Discussion of issues relating to Soaring in Australia." > Cc: > Sent:Thu, 5 May 2011 11:05:50 +1000 > Subject:Re: [Aus-soaring] Re NZ ASH on youtube. > > At 1:53: > "Maximum weight of this glider when fully loaded on a World record > with 2 > pilots and water ballast is 1.2 tons" > > I bet that's a test condition that the designer didn't envisage... > > Is the glider modified, or was that comment hyperbole or ignorance? > > -----Original Message----- > From: [email protected] [1] > [mailto:[email protected] [2]] On Behalf Of > Mike > Borgelt > Sent: Wednesday, 4 May 2011 6:47 PM > To: Discussion of issues relating to Soaring in Australia. > Subject: Re: [Aus-soaring] Re NZ ASH on youtube. > > At 05:50 PM 4/05/2011, you wrote: > >Well Aerodynamicists, is it really fluttering after the anhederal? > >Peter Heath - > > It looks like he had landing flap deployed then went to negative. In > the > Schleicher gliders the landing flap transfers the lift to the inner > part of > the wing and the tips then hang down or at higher speeds could even > lift > downwards, hence the anhedral. > > Sure looks like flutter to me, initiated by the impulse of moving the > lift > outboard suddenly. This probably isn't a test condition that the > designer > envisaged. > Fortunately the flutter was damped and ceased after a few > oscillations. > > Mike > > Borgelt Instruments - manufacturers of quality soaring instruments > since > 1978 phone Int'l + 61 746 355784 > fax Int'l + 61 746 358796 > cellphone Int'l + 61 428 355784 > > email: [email protected] [3] > website: www.borgeltinstruments.com [4] > > _______________________________________________ > Aus-soaring mailing list > [email protected] [5] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring [6] > ----- > No virus found in this message > Checked by AVG - www.avg.com [7] > Version: 10.0.1325 / Virus Database: 1500/3616 - Release Date: > 05/04/11 > > _______________________________________________ > Aus-soaring mailing list > [email protected] [8] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring [9] > @lists.internode.on.net> > > Links: > ------ > [1] mailto:[email protected] > [2] mailto:[email protected] > [3] mailto:[email protected] > [4] http://www.borgeltinstruments.com > [5] mailto:[email protected] > [6] http://lists.internode.on.net/mailman/listinfo/aus-soaring > [7] http://www.avg.com > [8] mailto:[email protected] > [9] 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
