Gliding risk....

On Wednesday, December 4, 2019 at 8:43:39 PM UTC-8, 5Z wrote:
On Wednesday, December 4, 2019 at 7:53:57 PM UTC-8, son_of_flubber wrote:
On Wednesday, December 4, 2019 at 4:54:08 PM UTC-5, 2G wrote:

Before I purchased any glider manufactured by either of these subcontractors I would insist on a full-blown ultrasonic NDT test.

This relevant accident happened in 2003.

Before I get my nickers in a twist, I'd like to know whether the manufacturing deficiencies have been addressed in the intervening 16 years.

Sounds like a recent story about Boeing...
https://boingboing.net/2019/12/02/ra...-shavings.html

"...Barnett says the 787 facility was run by a new leadership team that had been transferred in from St Louis, MO, with a background in overseeing military contracts, and that they prioritized production speed over airworthiness and safety.

He says that the culture of poor safety began in 2011 or 2012, with top management ordering employees not to document defects, but that this graduated to "ignoring safety issues and the defective parts." Barnett pursued this internally, exhausting every internal process and facing workplace retaliation before going to federal regulators like the FAA and OSHA, which resulted in even more retaliation, and, eventually, blackballing across the aviation industry."

Yeah, Boeing used to be run be engineers in Seattle. That changed when they moved their headquarters to Chicago in 2001. Now, engineers became a necessary nuisance and profit became king. When they tried to farm out most subsections of the 787, with only final assembly being done in Seattle, they ran into major problems: the subs really didn't know how to make aircraft. These are the kind of blunders bean-counters make, with no sense of what made the company great. The 737 Max is just the latest, if not the worst, blunder. They didn't even designate the MCAS as flight critical, so it didn't get the attention it deserved. And then they charged extra for it to operate off of both AOA sensors that were on the plane anyhow - a colossal bean-counter screw-up: charge extra for basic safety! Heads need to roll in top management, although they will wait until after the current crisis is over.

On Wednesday, December 4, 2019 at 10:53:57 PM UTC-5, son_of_flubber wrote:
On Wednesday, December 4, 2019 at 4:54:08 PM UTC-5, 2G wrote:

Before I purchased any glider manufactured by either of these subcontractors I would insist on a full-blown ultrasonic NDT test.

This relevant accident happened in 2003.

Before I get my nickers in a twist, I'd like to know whether the manufacturing deficiencies have been addressed in the intervening 16 years.

SH issued an AD on affected ships. Presumably all were inspected and repaired as needed a long time ago.
I recall that SH did take action to document the process areas that had been done only by hands on training. I don't have written info on this.
SH stepped up on this and did what I consider a good job when the issue was identified. I had an affected glider at the time and the inspection was prompt, thorough, and cost free.
UH

On Wednesday, December 4, 2019 at 1:54:08 PM UTC-8, 2G wrote:
On Friday, November 22, 2019 at 11:49:15 AM UTC-8, john firth wrote:
On Wednesday, October 30, 2019 at 8:49:22 PM UTC-4, wrote:
For those who haven’t seen it....

https://chessintheair.com/the-risk-o...-what-we-love/

Great piece of work which I shall read again in March!

A few comments;

"if you dread the thought of a field landing....."
then you should set up a simulation on your own field and practice till
you are confident.

No pilot should EVER be criticised for deciding on a field landing; I suppose this must happen; very immature behavior.

Duo Discus in flight wing failure.
The German report ( thanks Google) says that there was an unbonded section
on the spar some 20cm long. Surely an ultrasound scan of the spar line
would reveal this. I have no experience/ expertise in this regard.

John Firth

Thanks for pointing the Duo Discus manufacturing problem. Here is a link to the BFU report:
https://www.bfu-web.de/EN/Publicatio...ublicationFile

A couple of disturbing findings in this report:

"Manufacture of the wings was based on the knowledge of Schempp-Hirth at Kircheim which was not available as written instructions. This was true for the processes during manufacture, the specification of materical (e.g. adhesives) and the criteria for quality assurance (tolerances)."

Instead, employees from the subcontractors spent time at Kircheim to learn all of this. This system would utterly fail any quality control evaluation (e.g. CE), and is disturbing to me as a potential customer. Furthermore, this was the SECOND wing failure of an S-H product in the same year:

"The accident to the Discus CS in France revealed an even more extensive bonding defect on the wing spar."

This Discus had been in service for some time prior to the failure (900 hrs and 900 launches), so time in service is no security blanket. All Discus gliders were grounded in France after this accident:

https://groups.google.com/forum/#!to...ng/MTRTAwPn7qA

Yes, ultrasonic nondestructive testing can reveal such defects, but I don't know of any glider repair facilities that use them. I have designed such products in the past and have connections with a local NDT company. I will reach out to them to see how feasible such testing is. In the mean time, you can do a crude kind of NDT test by tapping on the surface above the bond with a metal object like a coin and listen to the sound produced. A defective bond will sound different than a good bond (less sharp and duller):

https://www.aviationpros.com/home/ar...aft-composites

Before I purchased any glider manufactured by either of these subcontractors I would insist on a full-blown ultrasonic NDT test.

Tom

Tom did you get this NDT done to your ASH-31mi? Just curious if the Manufacturers provide this service. I couldn't even get an airbrushing.

Yeah, the entire fleet was inspected and repaired as required (years ago), and SH paid for the whole thing. Gliders built at the factory in Germany were found to be affected, as well as those built at contractors.

Lynn Alley
"2KA"

At 16:14 05 December 2019, 2KA wrote:
Yeah, the entire fleet was inspected and repaired as required
(years ago),
and SH paid for the whole thing. Gliders built at the factory
in Germany
were found to be affected, as well as those built at
contractors.

Lynn Alley
"2KA"

You were lucky! I was in a UK owned DuoDiscus based at
Sisteron, France, a few years ago. Wing spar de-bonding was
discovered at an annual inspection even though the glider had,
in theory, been inspected previously, looking for this specific
manufacturing fault. SH DECLINED TO PAY FOR THIS REPAIR;
if I recall correctly each of us in the 8 man syndicate had to
cough up about £700.......
Dave Walsh

At 19:09 05 December 2019, Dave Walsh wrote:
At 16:14 05 December 2019, 2KA wrote:
Yeah, the entire fleet was inspected and repaired as required
(years ago),
and SH paid for the whole thing. Gliders built at the factory
in Germany
were found to be affected, as well as those built at
contractors.

Lynn Alley
"2KA"

You were lucky! I was in a UK owned DuoDiscus based at
Sisteron, France, a few years ago. Wing spar de-bonding was
discovered at an annual inspection even though the glider had,
in theory, been inspected previously, looking for this specific
manufacturing fault. SH DECLINED TO PAY FOR THIS REPAIR;
if I recall correctly each of us in the 8 man syndicate had to
cough up about £700.......
Dave Walsh

I inspected this glider in compliance with the AD, and was accused of
not inspecting it correctly! It was subsequently discovered an
undocumented wing change had taken place. Not all inspectors or repair
shops are honest!

Terry Slater

On Thursday, December 5, 2019 at 7:53:33 AM UTC-8, Jonathan St. Cloud wrote:
On Wednesday, December 4, 2019 at 1:54:08 PM UTC-8, 2G wrote:
On Friday, November 22, 2019 at 11:49:15 AM UTC-8, john firth wrote:
On Wednesday, October 30, 2019 at 8:49:22 PM UTC-4, wrote:
For those who haven’t seen it....

https://chessintheair.com/the-risk-o...-what-we-love/

Great piece of work which I shall read again in March!

A few comments;

"if you dread the thought of a field landing....."
then you should set up a simulation on your own field and practice till
you are confident.

No pilot should EVER be criticised for deciding on a field landing; I suppose this must happen; very immature behavior.

Duo Discus in flight wing failure.
The German report ( thanks Google) says that there was an unbonded section
on the spar some 20cm long. Surely an ultrasound scan of the spar line
would reveal this. I have no experience/ expertise in this regard.

John Firth

Thanks for pointing the Duo Discus manufacturing problem. Here is a link to the BFU report:
https://www.bfu-web.de/EN/Publicatio...ublicationFile

A couple of disturbing findings in this report:

"Manufacture of the wings was based on the knowledge of Schempp-Hirth at Kircheim which was not available as written instructions. This was true for the processes during manufacture, the specification of materical (e.g. adhesives) and the criteria for quality assurance (tolerances)."

Instead, employees from the subcontractors spent time at Kircheim to learn all of this. This system would utterly fail any quality control evaluation (e.g. CE), and is disturbing to me as a potential customer. Furthermore, this was the SECOND wing failure of an S-H product in the same year:

"The accident to the Discus CS in France revealed an even more extensive bonding defect on the wing spar."

This Discus had been in service for some time prior to the failure (900 hrs and 900 launches), so time in service is no security blanket. All Discus gliders were grounded in France after this accident:

https://groups.google.com/forum/#!to...ng/MTRTAwPn7qA

Yes, ultrasonic nondestructive testing can reveal such defects, but I don't know of any glider repair facilities that use them. I have designed such products in the past and have connections with a local NDT company. I will reach out to them to see how feasible such testing is. In the mean time, you can do a crude kind of NDT test by tapping on the surface above the bond with a metal object like a coin and listen to the sound produced. A defective bond will sound different than a good bond (less sharp and duller):

https://www.aviationpros.com/home/ar...aft-composites

Before I purchased any glider manufactured by either of these subcontractors I would insist on a full-blown ultrasonic NDT test.

Tom

Tom did you get this NDT done to your ASH-31mi? Just curious if the Manufacturers provide this service. I couldn't even get an airbrushing.

No, I haven't and no they don't. The company I have ties with is local and I might interest them in a new market. I have to get to feeling better before I try.

NDT is only one way to do the inspection, although it is unquestionably the most convenient (no drilling of holes).

Tom

On Thursday, December 5, 2019 at 11:15:08 AM UTC-8, Dave Walsh wrote:
At 16:14 05 December 2019, 2KA wrote:
Yeah, the entire fleet was inspected and repaired as required
(years ago),
and SH paid for the whole thing. Gliders built at the factory
in Germany
were found to be affected, as well as those built at
contractors.

Lynn Alley
"2KA"

You were lucky! I was in a UK owned DuoDiscus based at
Sisteron, France, a few years ago. Wing spar de-bonding was
discovered at an annual inspection even though the glider had,
in theory, been inspected previously, looking for this specific
manufacturing fault. SH DECLINED TO PAY FOR THIS REPAIR;
if I recall correctly each of us in the 8 man syndicate had to
cough up about £700.......
Dave Walsh

This is particularly disturbing, raising the question of the effectiveness of the original inspection method(s). Do the logbook(s) detail how and when this inspection was done? How did the current annual discover the de-bonding?

Tom

At 22:33 05 December 2019, 2G wrote:
On Thursday, December 5, 2019 at 11:15:08 AM UTC-8, Dave Walsh wrote:
At 16:14 05 December 2019, 2KA wrote:
Yeah, the entire fleet was inspected and repaired as required=20
(years ago),
and SH paid for the whole thing. Gliders built at the factory=20
in Germany
were found to be affected, as well as those built at=20
contractors.

Lynn Alley
"2KA"
=20
You were lucky! I was in a UK owned DuoDiscus based at=20
Sisteron, France, a few years ago. Wing spar de-bonding was=20
discovered at an annual inspection even though the glider had,=20
in theory, been inspected previously, looking for this specific=20
manufacturing fault. SH DECLINED TO PAY FOR THIS REPAIR;=20
if I recall correctly each of us in the 8 man syndicate had to=20
cough up about =C2=A3700.......
Dave Walsh

This is particularly disturbing, raising the question of the
effectiveness
=
of the original inspection method(s). Do the logbook(s) detail how and
when=
this inspection was done? How did the current annual discover the
de-bondi=
ng?

Tom

The inspections were performed with an endoscope, and the full length of
the spar bonding was inspected visually. SH issued a very comprehensive
guide to the process.

Terry

On Wednesday, November 6, 2019 at 2:34:02 PM UTC-5, wrote:
“Proof - put a dummy in a glider and launch it.�

We see many “dummies being launched each week, and they’re not maniquines but real dumb flesh n blood.

I have seen many of those in my day, go ahead and let them go! Mistakes do happen, careless assembly almost cost me my life as a very young glider pilot. Wish I would have read the book, Glider Assembly For Dummies. Bob