(USA) Blanik L-13 - calling all NDI specialists
mike malis
the Mfg. This is going to take a lot af time and effort, if it even
works at all, and there is no way to say if the final repair will be
economically feasible.
However, there are new inspection methods that hold promise, such as
real time X-ray. It can look though skins and see cracks in wing spar
caps on transport aircraft structure, and without removing fasteners.
If we proove we can detect cracks, I don't see how the Mfg can refute
this approach, AFTER ALL, their approach so far has been inspection
for continued airworthiness, for this fatigue problem they have know
about for 35 years.
There is a nationwide NDI conference coming up. If anyone knows any
NDI or quality engineers, ask them to find out if they know of anyone
going to this conference:
http://www.asnt.org/events/conferences/fc10/exhibitorlist.htm
It might be our best chance....Remember, the accident aircraft had 8
areas of fatigue cracking, and there has never been an documented
accident due to L-13 fatigue failure in the USA.
Tim Taylor
The Australians have had an approved use of Eddy Current testing on
the Blanik for years. Why can we not use their data and method and
get an approved method with that as well? They have been the leaders
in this area for over 20 years. They would be a better authority to
get approval than EASA as far as I can tell.
mike malis
> the Blanik for years. Why can we not use their data and method and
> get an approved method with that as well?
We can, but to my knowledge, that was never approved by the Mfg. Do
you want to rely on that? Do you want to wait for the MFG to
approve? You will have to access/remove the 3 rivets where the
triangular cracking pattern showed on the accident , install H-Locs,
and repeat every 500 hrs. I have reservations about this process
anyway.
The ONLY reason we have the current AD is the the Mfg reccommended
inspection method does not work. If we find one that does, It will be
hard for the Mfg not to agree....
aerodyne
T8
> Remember, the accident aircraft had 8
> areas of fatigue cracking
Link, please?
-T8
mike malis
See the AD preamble...
jcarlyle
aircraft since 1970. While I'm not familiar with the precise situation
in the L-13 spar, I can say that developing an NDT method you could
"prove" will detect cracks in that spar will be somewhat involved and
moderately expensive. I can also say that your chances of positively
detecting all cracks with real-time radiography are practically zero
(this is because of the poor ability of a density sensitive technique
to find a tight crack).
The hardest part of any NDT technique development is making a standard
or two, that replicate the most benign defect condition you must find,
in the most difficult place in the part. Those standards must be used
by the technician prior to each inspection to prove that his technique
and the instrument as currently adjusted can positively find the least
worrisome crack of concern.
Therefore, I would recommend that you improve the Austrailian EC
technique. You've already got some field history there, and there are
probably standards as well. Tweaking the technique or using a
different instrument and/or probe might resolve the reservations you
have about it. In any case, it would be much faster than starting from
scratch.
-John
On Sep 2, 1:31 am, mike malis <aerodyneservi...@gmail.com> wrote:
aero...@socal.rr.com
John;
I think we can do better than a 30 year old process.
NOT trying to develop something new, what I am suggesting is done in
production on FFC military flying hardware...
jcarlyle
following this route. Taking a technique developed for one situation
and trying to use it to find cracks in a different situation is a crap
shoot.
However, since you desire something that will impress the
manufacturer, can I interest you in an in-flight capable fatigue crack
detection method? I developed it for inspecting F-111 critical
structure (did the whole US, British and Australian fleets): applied
it to the entire VC-10 fleet to find tiny pressure hull fatigue
cracks; used it on 707, 720, 727, 737, 747, JAS-39, E-2C, F-15, F-14,
CF-5, A-4, C-141 (some during full scale catapault operation fatigue
testing), and it's been used in in-flight testing on C-5, CF-100,
MB-326, KC-135. This acoustic method's chances of finding small, tight
fatigue cracks are much better than real-time radiography, there's no
radiation hazard, and as a bonus it offers flashing lights and sound.
Might cost a little more than your Blanik is worth to inspect it, but
boy, it'd be cool!
-John
Papa3
> I wish you the best of luck, but I don't think you'll succeed
> following this route. Taking a technique developed for one situation
> and trying to use it to find cracks in a different situation is a crap
> shoot.
>
> However, since you desire something that will impress the
> manufacturer, can I interest you in an in-flight capable fatigue crack
> detection method? I developed it for inspecting F-111 critical
> structure (did the whole US, British and Australian fleets): applied
> it to the entire VC-10 fleet to find tiny pressure hull fatigue
> cracks; used it on 707, 720, 727, 737, 747, JAS-39, E-2C, F-15, F-14,
> CF-5, A-4, C-141 (some during full scale catapault operation fatigue
> testing), and it's been used in in-flight testing on C-5, CF-100,
> MB-326, KC-135. This acoustic method's chances of finding small, tight
> fatigue cracks are much better than real-time radiography, there's no
> radiation hazard, and as a bonus it offers flashing lights and sound.
> Might cost a little more than your Blanik is worth to inspect it, but
> boy, it'd be cool!
>
> -John
>
> On Sep 3, 12:28 am, aerod...@socal.rr.com wrote:
>
That's all well and good, but can it whistle The Magic Flute?
jcarlyle
depending on the results being found.
-John
HZ
I tell you, have this experience with it... Nobody is taking care
about something till this time when something happen - somebody died.
Australian dealer for Blaniks was Bill Rilley. I know him very well
not only because I am Czech from where Blanik's came but I am offen in
Tocumwal from where Bill is. The engineer who did great job on all
Blanik's which came to Australia is Mike Burns. The some expert who
found a lot of faults on Diana 2 which I took for registration
procedure to Australia nearly 4 years ago. He found a lot of troubles
on this glider, not only on this serial number. A lot of production
and design faults. Till now he is popularized by a lot of people,
functionars and pilots, producre as first, as somebody who did all
wrongs on Diana 2. Nobody is watching that this serial number is still
not flying if it was setnt back to producer nearly 3 years ago and
this serial number is not flying till yet.
You can find some details at forum about Diana
http://groups.google.com/group/rec.aviation.soaring/browse_thread/thread/5f21a4c185a6f729?hl=en
Trouble is that if somebody came with argue which can prevent a lot,
everyone is going backward....
Have safe flying - it means be thinking!!!
Hana Zejdova