---------------------------------------------------------- Lightning-List Digest Archive --- Total Messages Posted Wed 08/11/10: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:21 AM - Re: Lightning Elevator flutter (robert keen) 2. 06:22 AM - Re: Lightning Elevator flutter (robert keen) 3. 07:29 AM - Latest newsletter (flylightning) ________________________________ Message 1 _____________________________________ Time: 06:21:38 AM PST US From: "robert keen" Subject: RE: Lightning-List: Lightning Elevator flutter Yes I am sure you are correct I am currently removing gap seal and retaping wing roots, I am sure it will fix the problem. This is the only change to the aircraft from new. Cheers Smokey From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of Dave Sent: Tuesday, 10 August 2010 9:22 AM Subject: Re: Lightning-List: Lightning Elevator flutter Smokey I have an Esqual, installed gap seals, had stick "shimmy" thinking it to be "flutter". Removed gap seals and all is good, this was happening at 135 to 140. My question, do you have gap seals on? Dave ----- Original Message ----- From: robert keen Sent: Sunday, August 08, 2010 5:13 PM Subject: RE: Lightning-List: Lightning Elevator flutter Nick, I have experienced elevator flutter twice at around 140 knots indicated. I was told by the Australian agent Dennis, that it would be a loose tape under the wing. I have not yet retaped the wing joint yet, but I would like the Mass Balance figures so I can check the elevator myself. Can you send me the info please? I will keep you posted on what I find. Also do you have the mass balance figures for the ailerons? Should the Lightning have bungie cords on the elevator pushrod to hold some weight? Thanks Smokey. From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of flylightning Sent: Thursday, 5 August 2010 11:06 PM Subject: RE: Lightning-List: Lightning Elevator flutter No. Did you experience this or just simply asking? The prototype was mass balanced at first but when looking at light sport and saving weight we removed the balances and retested. There was no evidence of flutter. We dive test every LSA Lightning to Vne, 180knts IAS ( 208mph) with proper attempts to induce flutter with no issues. It is required by the ASTM on every aircraft. Nick Otterback Arion Aircraft, LLC _____ From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of robert keen Sent: Thursday, August 05, 2010 3:06 AM Subject: Lightning-List: Lightning Elevator flutter Has anyone had a problem with elevator flutter? Can anyone tell me the mass balance limits of the lightning control surfaces? Thanks Smokey http://www.matronics.com/Navigator?Lightning-List http://forums.matronics.com http://www.matronics.com/contribution http://www.matronics.com/Navigator?Lightning-List http://forums.matronics.com http://www.matronics.com/contribution Internal Checked by AVG - www.avg.com 18:25:00 href="http://www.matronics.com/Navigator?Lightning-List">http://www.matronic s.com/Navigator?Lightning-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c Checked by AVG - www.avg.com 18:25:00 ________________________________ Message 2 _____________________________________ Time: 06:22:23 AM PST US From: "robert keen" Subject: RE: Lightning-List: Lightning Elevator flutter All is in good condition and I think it is the gap seal on the elevator, will know soon. When I experienced the flutter like symptoms it was not possible to hold the elevator from moving up and down, it ceased as soon as I slowed a few knots and It only lasted a couple of seconds as I was increasing speed slowly at the time. Cheers Smokey From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of N1BZRich@aol.com Sent: Monday, 9 August 2010 1:12 PM Subject: Re: Lightning-List: Lightning Elevator flutter Hi Smokey, I don't want to totally disagree with your flutter assessment, but I kind of doubt that what you felt was true elevator flutter. Here is why - Many other Lightning builders, during the 40 hour phase one test period, have flown their Lightnings to Vne without any hint of flutter. And in the case of the prototype, Nick and I have flown it to well beyond the published Vne in several different stabilizer/elevator configurations. First, with the full aerodynamic and dynamic counter balance, they with a lesser modified configuration (not as large an aerodynamic counterbalance), and finally with no aerodynamic counter balance at all. In each case, absolutely no flutter, or to be more specific not even any indication of flutter. So if your airplane is having a problem, something may be different about your airplane. But lets not totally rule it out yet until we know more from you. So can you give us some more information to go on? For example, you said it happened twice at about 140 knots indicated. Was that the first two times you had your Lighting to 140 knots? Or has it been beyond that before with no problems on other occasions? When it happened, what did you feel (or see) to make you think elevator flutter? Was the stick moving? If so, could you freeze the stick with hand pressure? What did you do to case what ever was happening to stop happening? Did it stop immediately whey you did that? How much flying time on your airplane? Have you checked the elevator control system to see if there is excess slop in the system? Is anything looser now than before? I have seen at least one case where some rod end bearings developed some slop and the extra slop did cause some minor aileron buzz but no real buffet. Do you have the modification with the elevator trim tab? If so has that tab been there all along? And if so, how is the hinge for the tab? Has it loosened up? Sorry for all the questions, but these kind of things will help diagnose the problem and come up with a fix. As Dennis hinted at, with no tape between the wing and the fuselage karman, you will probably have a higher stall speed and some strange buffet feelings, but it is not flutter. So you might want to check that area. Other than the above, I can offer no other suggestions until we hear more from you. Nick will certainly jump in here when he see this on Monday morning. Rest assured that the Lightning is one of the more thoroughly tested designs out there. It is way stronger and thus safer than it has to be, but that is the basic design philosophy that Arion goes by - better than the others. I look forward to hearing from you. Blue Skies, Buz In a message dated 8/8/2010 6:15:48 P.M. Eastern Daylight Time, smokeysmail@bigpond.com writes: Nick, I have experienced elevator flutter twice at around 140 knots indicated. I was told by the Australian agent Dennis, that it would be a loose tape under the wing. I have not yet retaped the wing joint yet, but I would like the Mass Balance figures so I can check the elevator myself. Can you send me the info please? I will keep you posted on what I find. Also do you have the mass balance figures for the ailerons? Should the Lightning have bungie cords on the elevator pushrod to hold some weight? Thanks Smokey. From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of flylightning Sent: Thursday, 5 August 2010 11:06 PM Subject: RE: Lightning-List: Lightning Elevator flutter No. Did you experience this or just simply asking? The prototype was mass balanced at first but when looking at light sport and saving weight we removed the balances and retested. There was no evidence of flutter. We dive test every LSA Lightning to Vne, 180knts IAS ( 208mph) with proper attempts to induce flutter with no issues. It is required by the ASTM on every aircraft. Nick Otterback Arion Aircraft, LLC _____ From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of robert keen Sent: Thursday, August 05, 2010 3:06 AM Subject: Lightning-List: Lightning Elevator flutter Has anyone had a problem with elevator flutter? Can anyone tell me the mass balance limits of the lightning control surfaces? Thanks Smokey http://www.matronics.com/Navigator?Lightning-List http://forums.matronics.com http://www.matronics.com/contribution http://www.matronics.com/Navigator?Lightning-List http://forums.matronics.com http://www.matronics.com/contribution Internal Checked by AVG - www.avg.com 18:25:00 =================================== t href="http://www.matronics.com/Navigator?Lightning-List">http://www.matronic s.com/Navigator?Lightning-List =================================== ms.matronics.com/">http://forums.matronics.com =================================== tp://www.matronics.com/contribution">http://www.matronics.com/contribution =================================== Checked by AVG - www.avg.com 18:25:00 ________________________________ Message 3 _____________________________________ Time: 07:29:54 AM PST US From: "flylightning" Subject: Lightning-List: Latest newsletter Buz, Once again a great newsletter this month. As an update Ricks lightning has flown and seems to be doing well, only comments are its alot different than his Maule! But in a good way. Not sure what number we have here but Mark the "potentate of numbers" and other things can tell us. As an update on the new top secret homebuilt project going on here we are 9 weeks along and should be completed in time for Sun n Fun! 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