If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
DG-300/303 owners...
|
#12
|
|||
|
|||
DG-300/303 owners...
On Apr 17, 1:11 am, Ann O'Rack wrote:
At 07:36 17 April 2007, wrote: On Apr 16, 3:48 pm, 'Dan G' wrote: On Apr 16, 9:26 pm, ' wrote: Such a major flaw in a wing spar should be replaced at the manufacturers expense IMHO. If Boeing shipped a plane that was discovered to have a flaw in it because their sub contractor failed to adhere to manufacturing specs or QA procedures, Boeing would fix the problem then deal with the sub. After all Boeing owns the paper for the sales contract. So what is different here? What is different is that the manufacturing company (Glaser-Dirks) no longer exists, would you expect DG to be responsible for a manufacturing problem in, e.g., an LS3 also? Yes they could come up with a better solution than they have so far but expecting them to pay for it just because they sell the spare parts is a fantasy. DG acquired the IP and remains of the old Glaser-Dirks. When acquiring the rights and user base to a company like that you cant just pick and choose what you take responsibility for. Also the 303's have been built by the new company so where do you draw the line? Plus DG also retained the original manufacturer (Elan/AMS). |
#13
|
|||
|
|||
DG-300/303 owners...
On 17 Apr 2007 00:33:55 -0700, "
wrote: So what is different here? Boeing is still in business. manufacturer of the DG-300/303 was Glaser Dirks which has been out of business for several years now. The current company DG Flugzeugbau merely does the service for all the former Glaser Dirks aircraft prior to the DG-800. It will only take one crusty in his DG flying the old placard speeds, making it clap hands and they are in a whole heap of trouble. The fact that no DG-300 ever loast its wings clearly proves that the structure is strong enough to handle the flight loads. This is a nightmare for DG300/303 owners, I almost became an owner last summer as I was looking at a DG303 acro. if you want to do aerobatocs in a 303, you're screwed. 99.9 percent of all other DG-300 pilots won't even notice the restrictions. Bye Andreas |
#14
|
|||
|
|||
DG-300/303 owners...
On Tue, 17 Apr 2007 01:39:59 +0100, John Schaffer
wrote: I have sent a email to the factory, with no reply. I am guessing that it would cost me $21K USD to get my wings fixed. Does anyone have any idea on the cost of new wings from the factory? Would it be cheaper for me? How often do you feel the need to fly with more than 450 kg and faster than 250 kph...? As long as you don't do that regularly, you can save a lot of money and simply apply the new restrictions to your airspeed indicator and POH. Bye Andreas |
#15
|
|||
|
|||
DG-300/303 owners...
That will not work.
Carbon fibre and glass fibre do not have the same stiffness. The carbon which is stiffer would have to carry the complete load and would break unless being designed/dimensioned to replace the complete spar. It makes no sense to mix the two in a spar like that. Best regards, Ola Røer Thorsen Steve Davis wrote: The wings are reparable so they shouldn't have to provide free replacements. Since it is a fiberglass spar cap and the problem seems to be limited to the wing root it MIGHT be possible to cut a slot into the rovings and embed some Graphlite carbon fiber rods into the spar cap. If this is doable the result could be a far stronger spar than the original design. I don't think you could do this with a carbon fiber spar cap but i'm not sure about fiberglass. http://www.marskeaircraft.com/carbonrod.html |
#16
|
|||
|
|||
DG-300/303 owners...
On Apr 17, 3:14 am, Andreas Maurer wrote:
On Tue, 17 Apr 2007 01:39:59 +0100, John Schaffer wrote: I have sent a email to the factory, with no reply. I am guessing that it would cost me $21K USD to get my wings fixed. Does anyone have any idea on the cost of new wings from the factory? Would it be cheaper for me? How often do you feel the need to fly with more than 450 kg and faster than 250 kph...? As long as you don't do that regularly, you can save a lot of money and simply apply the new restrictions to your airspeed indicator and POH. Bye Andreas Also, from your April 8 post: Apart from the max T/O weight (and the prohibition of aerobatics for the DG-303 Acro) none of this limitations is going to have any practical influence on aircraft handling, don't you agree? Andreas, do you own a DG-300? If not maybe you'd like to buy mine. I'm partly joking and partly serious with that comment. It's still a nice glider but it's not the glider I bought. Mine is not an acro but was approved for mild aerobatics and I did those aerobatics. I'll miss that. Also, I'd like to fly at 9.5 lbs/sq ft. or so sometimes. 525 kg isn't required for that but more than 450 kg is needed. With 450 kg only 9.0 is possible. The reduction in maneuvering speed is probably a bigger deal than Vne but I know people around here who have had trouble staying below 18,000 while at Vne. It's not very often though. ELAN seems to be the responsible party here. Are they still the same company? My understanding is they only split off the aviation division to form AMS but the original ELAN company is still the same. Please correct me if I'm wrong. Bob |
#17
|
|||
|
|||
DG-300/303 owners...
|
#18
|
|||
|
|||
DG-300/303 owners...
Andreas Maurer wrote:
Hi Bob, On 17 Apr 2007 16:58:55 -0700, wrote: Andreas, do you own a DG-300? If not maybe you'd like to buy mine. Thank you for your kind offer, but I (respectively my club) already own 2 DG-300... ... and the pilots who fly them regard stories about 18.000 ft cloud base and difficulties of staying below Vne as science fiction. What, you've never worried about the lift being too strong? You need to come west! Shawn |
#19
|
|||
|
|||
DG-300/303 owners...
'....and the pilots who fly them regard' might need
to be changed to 'the pilots who flew them regard' unless an inexpensive method of inspecting and repairing them is developed by someone. Thank you for your kind offer, but I (respectively my club) already own 2 DG-300... .... and the pilots who fly them regard stories about 18.000 ft cloud base and difficulties of staying below Vne as science fiction. ELAN seems to be the responsible party here. Are they still the same company? My understanding is they only split off the aviation division to form AMS but the original ELAN company is still the same. Please correct me if I'm wrong. I have no idea about the situation of ELAN - but I'm pretty sure that their product liability has expired. Bye Andreas |
#20
|
|||
|
|||
DG-300/303 owners...
On Apr 18, 12:30 pm, Steve Davis
wrote: '....and the pilots who fly them regard' might need to be changed to 'the pilots who flew them regard' unless an inexpensive method of inspecting and repairing them is developed by someone. Hmmm... I wonder who that "someone" might be. Whoever they are, they're pretty brave to get wrapped up in this mess. On the topic of inexpensive, that will have to be relative at best. From correspondence and conversation with various engineers and composites technicians, it appears that the scarf ratio for composite repairs is determined by the ratio of the shear strength of the epoxy to the tensile strength of the fibers. For a spar repair in E-glass, it seems to come out on the order of 40:1, and perhaps 15% greater for S-glass, let's say conservatively around 60:1. My guess, based on my experience with wet fiberglass layups, is that the degree of fiber "ondulation" will vary linearly through the depth of the spar cap. That is, the worst "ondulation" will be at the extreme outer fibers of the spar cap, and that there will be no ondulation at the inner (last laid) fibers, and half way through that depth the ondulation will be half as bad as the worst. The shame of that is that the extreme outer fibers of a cantilever beam are the ones with the greatest stress. Anyhow, if the "ondulation" varies as I guess, part of the inspection and repair process will be to assess what degree of "ondulation" is acceptable, and how much spar cap has to be ground away to get to acceptable fiber. Suppose, for example, that the "Ondulated" fiber were to extend down through 8mm of spar cap. Then you (or, more likely, the repair tech) would have to grind out a scarf that extends spanwise through 8*60=480mm, call it a half a meter of span plus probably the full length of the spar butt, call it a full meter. After grinding that out, you'd have to build up the material removed by laying in new straight rovings. After executing the spar scarf, you'd have to repair all the collateral damage inflicted on the wing skin when trenching down to the spar. Probably the easiest way to do that would be with a prefabricated patch panel, made in the original wing mold, that encompasses the sandwich directly over the first half-meter of spar plus 50mm or so chordwise fore and aft of the spar. The repair tech would fit this patch panel, splice the inner skin, and execute an outer skin scarf around the perimeter of the patch panel. After that, gelcoat, sand, and polish to hide. That is just my own half-informed guess at what the spar repair entails. Your actual mileage has already varied. The response to my own emails to DG has been on what I would call the chilly side. Their position on this matter seems to be holding firm as follows: * Supplementary explanations of the problem and surrounding issues (such as the one I posted earlier) are unhelpful, since the explanation posted on the DG Web site clearly addresses all aspects of the issue. Beyond that, only "experts" are qualified to understand the problem. * Photos of affected spars are unhelpful because only "experts" are qualified to read them, for everyone else they are just frightening. * The inspection must be performed by DG-trained workers. Regarding some of the repairs I've seen suggested, such as splinting the spar with Graphlite rod, I think that those are non-starters at best. I think that the only reasonable repair schemes are those that restore the structure to its as-designed strength and stiffness. Repairs that substantially alter the stress distribution through the structure could well cause other unknown and unexpected problems. Thanks, and best regards to all Bob K. Disclaimer: I'm the guy behind: http://www.hpaircraft.com/hp-24 I'm an amateur - don't try this at work! |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Beech Duke Owners/ex-Owners ple help... | Stanley | Owning | 12 | June 10th 16 12:36 AM |
DG-300/303 owners... | Marc Ramsey | Soaring | 34 | April 22nd 07 05:07 AM |
SHK Owners | [email protected] | Soaring | 1 | February 7th 06 07:37 PM |
R22 owners please help with AD 2004-06-52 | rotortrash | Rotorcraft | 20 | April 28th 04 04:33 PM |
Any UH-1 owners in here? | Jim | Rotorcraft | 7 | October 6th 03 02:33 AM |