A aviation & planes forum. AviationBanter

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.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Taurus glider for sale



 
 
Thread Tools Display Modes
  #21  
Old April 21st 19, 03:43 PM posted to rec.aviation.soaring
Bob Kuykendall
external usenet poster
 
Posts: 1,271
Default Taurus glider for sale

On Saturday, April 20, 2019 at 12:17:15 AM UTC-7, Chris Wedgwood

Slovenia has never been a Soviet Republic. Check your history.


Thanks for the correction, Chris, my bad!

--Bob K.
Ads
  #22  
Old April 21st 19, 04:04 PM posted to rec.aviation.soaring
Bob Kuykendall
external usenet poster
 
Posts: 1,271
Default Taurus glider for sale

On Saturday, April 20, 2019 at 11:07:40 PM UTC-7, 2G wrote:

There is a reason why fiberglass gliders are painted white: they can't withstand high temperatures...


It's a bit more complicated than that. We could have blue or black or red composite gliders if we really wanted. Unsurprisingly it comes down to economics.

There are epoxy resin systems that can be used to achieve a Tg well above those achieved by darkly colored surfaces exposed to direct sunlight. We're using one such system right now on some aircraft parts that for a variety of reasons must be painted black.

However, compared to the MGS285 system that has become the de facto standard for European sailplane manufacture, those high-temperature systems are generally some or all of:

* More expensive
* Harder to mix and use
* More toxic
* More sensitizing

Furthermore, for some such systems, the parts must be subjected to elevated post-cure just to make them tough enough to demold. And then they must get an even hotter post-cure after all the parts are assembled.

All of these reasons that high-temperature systems are a pain to use make them more expensive to use, and for no easily justified reason.

There is a critical temperature called the "glass transition temperature" which is where the plastic starts transitioning from a solid into a liquid.. A typical glass transition temp for fiberglass is 100C, well below the temps seen in that hanger fire. The fact that they canopy melted demonstrates that the temp was that high for some period of time.
https://en.wikipedia.org/wiki/Glass_transition


Our tests have shown that exceeding Tg does not necessarily weaken a composite structure; depending on a variety of factors it will quite likely regain all its former strength and stiffness once it cools down. Furthermore, the melting of the canopy is not necessarily an accurate indicator of the temperatures reached by the rest of the structure; clear acrylic plastic absorbs a lot of wavelengths that reflect off of a white painted surface.

--Bob K.

  #23  
Old April 21st 19, 05:18 PM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 253
Default Taurus glider for sale

On Sun, 21 Apr 2019 07:43:04 -0700, Bob Kuykendall wrote:

On Saturday, April 20, 2019 at 12:17:15 AM UTC-7, Chris Wedgwood

Slovenia has never been a Soviet Republic. Check your history.


Thanks for the correction, Chris, my bad!

Life in the former Yugoslavia wasn't all that different from life in
Soviet-era Czechoslovakia, Hungary, Romania and Bulgaria. At least that's
my impression from visiting/travelling through those countries during
1973-1991.

Dealing with border police and banks was much the same in all of them, so
I'd expect aircraft construction and regulation to have been pretty much
in line with Russian practise before 1991, with only gradual changes
until they joined the EU and came under EASA.


--
Martin | martin at
Gregorie | gregorie dot org
  #24  
Old April 21st 19, 07:15 PM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 564
Default Taurus glider for sale

On Sunday, April 21, 2019 at 8:04:21 AM UTC-7, Bob Kuykendall wrote:
On Saturday, April 20, 2019 at 11:07:40 PM UTC-7, 2G wrote:

There is a reason why fiberglass gliders are painted white: they can't withstand high temperatures...


It's a bit more complicated than that. We could have blue or black or red composite gliders if we really wanted. Unsurprisingly it comes down to economics.

There are epoxy resin systems that can be used to achieve a Tg well above those achieved by darkly colored surfaces exposed to direct sunlight. We're using one such system right now on some aircraft parts that for a variety of reasons must be painted black.

However, compared to the MGS285 system that has become the de facto standard for European sailplane manufacture, those high-temperature systems are generally some or all of:

* More expensive
* Harder to mix and use
* More toxic
* More sensitizing

Furthermore, for some such systems, the parts must be subjected to elevated post-cure just to make them tough enough to demold. And then they must get an even hotter post-cure after all the parts are assembled.

All of these reasons that high-temperature systems are a pain to use make them more expensive to use, and for no easily justified reason.

There is a critical temperature called the "glass transition temperature" which is where the plastic starts transitioning from a solid into a liquid. A typical glass transition temp for fiberglass is 100C, well below the temps seen in that hanger fire. The fact that they canopy melted demonstrates that the temp was that high for some period of time.
https://en.wikipedia.org/wiki/Glass_transition


Our tests have shown that exceeding Tg does not necessarily weaken a composite structure; depending on a variety of factors it will quite likely regain all its former strength and stiffness once it cools down. Furthermore, the melting of the canopy is not necessarily an accurate indicator of the temperatures reached by the rest of the structure; clear acrylic plastic absorbs a lot of wavelengths that reflect off of a white painted surface.

--Bob K.


Yes, it is always more complicated than what most people are interested in reading. But in the case of this glider, the manufacturer clearly considered it to be unairworthy, period. Further, without having the glider fully instrumented with thermocouples, no one can say how hot, and for how long, each part of the glider got. Absent such data, the only safe course of action is to declare it unairworthy unless the manufacturer details an inspection and test regimen that can assure the glider's safety and continued airworthiness.

Additionally, changing the serial number is a blatant effort to disguise the damage history of the glider and constitutes fraud, in my opinion.

Tom
  #25  
Old April 21st 19, 11:01 PM posted to rec.aviation.soaring
Scott Williams
external usenet poster
 
Posts: 190
Default Taurus glider for sale

On Wednesday, April 17, 2019 at 3:08:53 AM UTC-5, wrote:
In the Wings and Wheels classified ads there is listed a Taurus selflaunch glider for sale.
Originally it was N797SD, sn 107T503LSA. Currently carrying a different N number and serial number, but it is the same glider.
This Taurus was involved in a hangar fire about 4 years ago in Memphis, Tn. While the flames did not reach the glider temperatures were high enough to melt the canopy Plexiglas. That is a temperature of about 325 F.
The manufacturer, Pipistrel d.o.o of Ajdovscina, Slovenia has declared this glider un-airworthy and will provide no customer support. They are shocked that it has not been destroyed and is now considered safe for flight.
Caveat Emptor
Robert Mudd Pipistrel dealer and service center.


Of course the seller could just tell any potential buyer that the glider is declared unairworthy by the maker/type certificate owner. Might hurt the value though.
  #26  
Old April 22nd 19, 01:56 AM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 564
Default Taurus glider for sale

On Sunday, April 21, 2019 at 3:01:51 PM UTC-7, Scott Williams wrote:
On Wednesday, April 17, 2019 at 3:08:53 AM UTC-5, wrote:
In the Wings and Wheels classified ads there is listed a Taurus selflaunch glider for sale.
Originally it was N797SD, sn 107T503LSA. Currently carrying a different N number and serial number, but it is the same glider.
This Taurus was involved in a hangar fire about 4 years ago in Memphis, Tn. While the flames did not reach the glider temperatures were high enough to melt the canopy Plexiglas. That is a temperature of about 325 F.
The manufacturer, Pipistrel d.o.o of Ajdovscina, Slovenia has declared this glider un-airworthy and will provide no customer support. They are shocked that it has not been destroyed and is now considered safe for flight.
Caveat Emptor
Robert Mudd Pipistrel dealer and service center.


Of course the seller could just tell any potential buyer that the glider is declared unairworthy by the maker/type certificate owner. Might hurt the value though.


If the seller were going to disclose that he would have put it in the ad, which he didn't. The ad has been cancelled - wonder why?
  #27  
Old April 22nd 19, 03:26 AM posted to rec.aviation.soaring
Echo
external usenet poster
 
Posts: 99
Default Taurus glider for sale

Speaking of complicated, I have direct knowledge of this one, and it's a lot more complicated than you realize. Just know that the manufacturer declaring it's unairworthy has nothing to do with anything, other than them not getting their way. I'll leave it at that.
  #28  
Old April 22nd 19, 04:16 AM posted to rec.aviation.soaring
Scott Williams
external usenet poster
 
Posts: 190
Default Taurus glider for sale

On Sunday, April 21, 2019 at 9:26:20 PM UTC-5, Echo wrote:
Speaking of complicated, I have direct knowledge of this one, and it's a lot more complicated than you realize. Just know that the manufacturer declaring it's unairworthy has nothing to do with anything, other than them not getting their way. I'll leave it at that.




On Sunday, April 21, 2019 at 9:26:20 PM UTC-5, Echo wrote:
Speaking of complicated, I have direct knowledge of this one, and it's a lot more complicated than you realize. Just know that the manufacturer declaring it's unairworthy has nothing to do with anything, other than them not getting their way. I'll leave it at that.


I must admit, It's not my glider, nor is it my $60K, But, How does the type certificate holders specific determination Not have anything to do with it?
That information would surely matter to an insurance company, and should concern any potential buyer. I have no doubt any future incident with this particular airframe would draw the lawyers like Buzzards to a carcass. Makes me wonder if the last inspector to sign it off is comfortable, and did he know? and will the next one be made aware? I'd bet Five bucks the owner was the last A&P to sign off this glider. I apologize if my skepticism is showing.

P.S. respond here if anyone was the last inspector and I owe you five bucks..
  #29  
Old April 22nd 19, 04:37 AM posted to rec.aviation.soaring
son_of_flubber
external usenet poster
 
Posts: 1,434
Default Taurus glider for sale

On Sunday, April 21, 2019 at 11:04:21 AM UTC-4, Bob Kuykendall wrote:
....
Our tests have shown that exceeding Tg does not necessarily weaken a composite structure; depending on a variety of factors it will quite likely regain all its former strength and stiffness once it cools down.


Would the wings and fuselage sag and permanently deform in a hangar fire? Worse if only one wingtip was supported.

  #30  
Old April 22nd 19, 06:51 AM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 564
Default Taurus glider for sale

On Sunday, April 21, 2019 at 7:26:20 PM UTC-7, Echo wrote:
Speaking of complicated, I have direct knowledge of this one, and it's a lot more complicated than you realize. Just know that the manufacturer declaring it's unairworthy has nothing to do with anything, other than them not getting their way. I'll leave it at that.


As I said before, things are ALWAYS more complicated than they seem. But your assertion that the manufacturer's opinion on airworthiness is completely irrelevant is, simply, bizarre. Do you realize that the FAA could declare the glider unairworthy based on that opinion alone? This is not hypothetical - it happened to the Blanik L13. Unless you are willing to provide more information I will stick with my origin assessment.

Tom
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pipistrel Taurus: Club Glider? Phil Chidekel Soaring 3 February 29th 16 04:05 AM
Glider equipment for sale Roger Fowler[_3_] Soaring 0 August 2nd 14 06:05 PM
GLIDER 4 SALE BobD Soaring 0 March 16th 14 08:45 PM
Glider for Sale 5 ugly Soaring 1 December 8th 13 12:57 AM
Taurus Glider Ready for Flight Tests Michael Coates Soaring 5 April 5th 04 04:05 AM


All times are GMT +1. The time now is 01:32 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 AviationBanter.
The comments are property of their posters.