US L-13 AD

On Jul 15, 2:32*am, Darryl Ramm wrote:
On Jul 14, 8:26*am, Craig wrote:



On Jul 13, 5:36*pm, Darryl Ramm wrote:

On Jul 13, 5:29*pm, Craig wrote:

On Jul 13, 4:29*pm, Frank Whiteley wrote:

http://rgl.faa.gov/Regulatory_and_Gu....nsf/list/2010...

Effective July 19th, 2010

Am I reading correctly that no aerobatics are permitted after July
19th regardless of the outcome of the inspection?

Thanks,
Craig

Yes. That seems very clearly stated.

Darryl

Yes, I thought it was clearly stated too, just so draconian that it
was a bit difficult to believe. *No exit clauses based on total hours,
etc.

Cheers,
Craig

I don't see it as draconian. I see it as appropriate for a glider type
that has had a spar failure/fatal accident and the TC owner, EASA, and
FAA are allowing the type to keep flying after inspection and while
collecting critical data on cracking. You guys need to wait until the
field data is in and maybe you'll have a case to try to remove
limitations, but I'd not hold my breath.

Darryl

A whole lot of the field data is in. The highest hour Blaniks have
always been in Australia
and a large amount of work has already been done. The AD below was
issued in 1989:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%201.pdf

In summary, it reports the major fatigue susceptibilities of L13s and
gives various ways of
extending the life. The lower wing carry through plays a starring
role. One solution involving
new Hi-Loc fasteners and an eddy current inspection schedule is laid
out in the AD's Appendix B and in the
earlier (1984) AD160:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%202.pdf

This extended L-13 life to 12000hours and 50,000 launches - but it
does recommend that
aerobatics be limited to practice spins.

I don't know the current permitted Blanik life in the US and Europe
but the original LET were
reluctant to get involved in this 70s and 80s life extension work in
Australia. I believe their
view at the time was that the glider was designed for 3000 hours
(IIRC ?) and that is where
it should stay. I'd not be surprised if the current TC holders were
happy to see
most L-13s scrapped.

As Darryl says - don't hold your breath.

GC

On Jul 15, 3:53*am, Graemec wrote:

A whole lot of the field data is in. *The highest hour Blaniks have
always been in Australia
and a large amount of work has already been done. *The AD below was
issued in 1989:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%201.pdf

Thanks for posting that! It answers a question that I and some others
have been asking: "What the heck is the difference between an L-13A1
and a regular old L-13?

From the Australian GFA AD 369 document linked above:

+ In 1984 D.J Llewellen and Riley Aeronautics developed and
+ received C.A.A. certification for a modification of the Blanik
+ wing to extend its fatigue life to nominaly three times the
+ basic Blanik L-13 life.
+
+ Up to the date of this Airworthiness Directive 9 Blaniks have
+ been modified being re-certified as "BLANIK L-13A1 gliders.
+ Riley Aeronautics (Australia) Pty.Ltd. hold Supplemental
+ Type Certificate No 96-1 covering this modification program.

Thanks again, Bob K.

On Jul 15, 6:53*am, Graemec wrote:

A whole lot of the field data is in. *The highest hour Blaniks have
always been in Australia
and a large amount of work has already been done. *The AD below was
issued in 1989:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%201.pdf

In summary, it reports the major fatigue susceptibilities of L13s and
gives various ways of
extending the life. *The lower wing carry through plays a starring
role. *One solution involving
new Hi-Loc fasteners and an eddy current inspection schedule is laid
out in the AD's Appendix B and in the
earlier (1984) AD160:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%202.pdf

This extended L-13 life to 12000hours and 50,000 launches - but it
does recommend that
aerobatics be limited to practice spins.

I don't know the current permitted Blanik life in the US and Europe
but the original LET were
reluctant to get involved in this 70s and 80s life extension work in
Australia. *I believe their
view at the time was that the glider was designed for 3000 hours
(IIRC ?) and that is where
it should stay. *I'd not be surprised if the current TC holders were
happy to see
most L-13s scrapped.

As Darryl says - don't hold your breath.

GC

I guess we in the Rest Of The World ought to pay a little more
attention to goings on in Oz. Thanks for sharing this.

-Evan Ludeman / T8

On Jul 15, 3:53*am, Graemec wrote:
On Jul 15, 2:32*am, Darryl Ramm wrote:



On Jul 14, 8:26*am, Craig wrote:

On Jul 13, 5:36*pm, Darryl Ramm wrote:

On Jul 13, 5:29*pm, Craig wrote:

On Jul 13, 4:29*pm, Frank Whiteley wrote:

http://rgl.faa.gov/Regulatory_and_Gu....nsf/list/2010...

Effective July 19th, 2010

Am I reading correctly that no aerobatics are permitted after July
19th regardless of the outcome of the inspection?

Thanks,
Craig

Yes. That seems very clearly stated.

Darryl

Yes, I thought it was clearly stated too, just so draconian that it
was a bit difficult to believe. *No exit clauses based on total hours,
etc.

Cheers,
Craig

I don't see it as draconian. I see it as appropriate for a glider type
that has had a spar failure/fatal accident and the TC owner, EASA, and
FAA are allowing the type to keep flying after inspection and while
collecting critical data on cracking. You guys need to wait until the
field data is in and maybe you'll have a case to try to remove
limitations, but I'd not hold my breath.

Darryl

A whole lot of the field data is in. *The highest hour Blaniks have
always been in Australia
and a large amount of work has already been done. *The AD below was
issued in 1989:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%201.pdf

In summary, it reports the major fatigue susceptibilities of L13s and
gives various ways of
extending the life. *The lower wing carry through plays a starring
role. *One solution involving
new Hi-Loc fasteners and an eddy current inspection schedule is laid
out in the AD's Appendix B and in the
earlier (1984) AD160:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%202.pdf

This extended L-13 life to 12000hours and 50,000 launches - but it
does recommend that
aerobatics be limited to practice spins.

I don't know the current permitted Blanik life in the US and Europe
but the original LET were
reluctant to get involved in this 70s and 80s life extension work in
Australia. *I believe their
view at the time was that the glider was designed for 3000 hours
(IIRC ?) and that is where
it should stay. *I'd not be surprised if the current TC holders were
happy to see
most L-13s scrapped.

As Darryl says - don't hold your breath.

GC

Great information. Thanks,
Craig

Last weekend I got a bit more information about the "Llewellen
Modification" mentioned below. It is said to be a steel reinforcing
strap applied to the outside of the wing along the wing main spar for
2/3 semispan or so. If that is true, it's great from a structural
perspective. From the aerodynamic perspective, maybe not so much...

Thanks, Bob K.



On Jul 15, 7:31*am, Bob Kuykendall wrote:
On Jul 15, 3:53*am, Graemec wrote:

A whole lot of the field data is in. *The highest hour Blaniks have
always been in Australia
and a large amount of work has already been done. *The AD below was
issued in 1989:

http://2009.gfa.org.au/Docs/ADs/gfa%...0issue%201.pdf

Thanks for posting that! It answers a question that I and some others
have been asking: "What the heck is the difference between an L-13A1
and a regular old L-13?

From the Australian GFA AD 369 document linked above:

+ In 1984 D.J Llewellen and Riley Aeronautics developed and
+ received C.A.A. certification for a modification of the Blanik
+ wing to extend its fatigue life to nominaly three times the
+ basic Blanik L-13 life.
+
+ Up to the date of this Airworthiness Directive 9 Blaniks have
+ been modified being re-certified as "BLANIK L-13A1 gliders.
+ Riley Aeronautics (Australia) Pty.Ltd. hold Supplemental
+ Type Certificate No 96-1 covering this modification program.

Thanks again, Bob K.

On Jul 27, 6:21*pm, Bob Kuykendall wrote:
Last weekend I got a bit more information about the "Llewellen
Modification" mentioned below. It is said to be a steel reinforcing
strap applied to the outside of the wing along the wing main spar for
2/3 semispan or so. If that is true, it's great from a structural
perspective. From the aerodynamic perspective, maybe not so much...

Thanks, Bob K.

I knew someone who flew in such a modified L-13 in OZ. 9600 hours on
the airframe at the time IIRC. Commented that it didn't appear to
affect performance.

Whether someone will attempt a US AMC based on this mod remains to be
seen.

Frank Whiteley

Just think how much you'll save now on turbulator tape.

Scott