Rib stitching vs glueing

On 14 Oct 2005 17:34:46 -0700, wrote:

I vaguely remember reading in the FAA/NTSB archive about such an
incident. It was a while ago, so I may be a bit off. What I remember
was that the pilot was killed on impact and apparently he was aware of
some minor seperation and continued to fly the aircraft until it failed
catastrophically. Might have been another bird, but I think it was a
celebrity. I'm not 100% sure though. You might try searching the
accident database for the celebrity if you haven't already.


That sounds pretty much like what happened to Steve Wittman.
He put off fixing the problem until after he got to Oshkosh.

I spoke with a pilot recently who is from Florida. Somehow Wittman's
accident came up and this pilot opined that while it's true that the
fabric appears to have delaminated from the wing thus causing the
catastrophic flutter that seperated the wing from the fuselage, he
thinks the Air Force had a hand in the accident. He, and some others
from his area, feel that wake turbulence may have jolted the wing into
flutter. There were military aircraft flying low level practice
missions in the area where he went down, according to this guy.

He didn't think the fabric would have delaminated without some kind of
jolt.

I don't know, it was an old airplane that had been sitting around for
a long time and it was a relatively fast cruiser. It may have been
possible for the fabric to rip loose without any help from close
passing B1's.

Corky Scott

wrote:
On 14 Oct 2005 17:34:46 -0700, wrote:

I vaguely remember reading in the FAA/NTSB archive about such an
incident. It was a while ago, so I may be a bit off. What I remember
was that the pilot was killed on impact and apparently he was aware of
some minor seperation and continued to fly the aircraft until it failed
catastrophically. Might have been another bird, but I think it was a
celebrity. I'm not 100% sure though. You might try searching the
accident database for the celebrity if you haven't already.


That sounds pretty much like what happened to Steve Wittman.
He put off fixing the problem until after he got to Oshkosh.

I spoke with a pilot recently who is from Florida. Somehow Wittman's
accident came up and this pilot opined that while it's true that the
fabric appears to have delaminated from the wing thus causing the
catastrophic flutter that seperated the wing from the fuselage, he
thinks the Air Force had a hand in the accident. He, and some others
from his area, feel that wake turbulence may have jolted the wing into
flutter. There were military aircraft flying low level practice
missions in the area where he went down, according to this guy.

Prior to the release of the FAA report there was speculation about
that in the rec.aviation newsgroups:

http://groups.google.com/group/rec.a...e=source&hl=en

And that an improper bolt may have been used in the horizontal
stabilizer:

http://groups.google.com/group/rec.a...e=source&hl=en

The FAA accident report (link appears earlier in this thread) refers
to both issues. They ruled out B1 turbulence and do not appear to
have drawn any conclusions as to the latter.


He didn't think the fabric would have delaminated without some kind of
jolt.

Respecfully, did he personally see the O & O special, ever?


I don't know, it was an old airplane that had been sitting around for
a long time and it was a relatively fast cruiser. It may have been
possible for the fabric to rip loose without any help from close
passing B1's.


--

FF

Steve's plane was less than 10 years old I believe at the time of the
accident. Not very old as plane go.


wrote in message
...
On 14 Oct 2005 17:34:46 -0700, wrote:

I vaguely remember reading in the FAA/NTSB archive about such an
incident. It was a while ago, so I may be a bit off. What I remember
was that the pilot was killed on impact and apparently he was aware of
some minor seperation and continued to fly the aircraft until it failed
catastrophically. Might have been another bird, but I think it was a
celebrity. I'm not 100% sure though. You might try searching the
accident database for the celebrity if you haven't already.


That sounds pretty much like what happened to Steve Wittman.
He put off fixing the problem until after he got to Oshkosh.

I spoke with a pilot recently who is from Florida. Somehow Wittman's
accident came up and this pilot opined that while it's true that the
fabric appears to have delaminated from the wing thus causing the
catastrophic flutter that seperated the wing from the fuselage, he
thinks the Air Force had a hand in the accident. He, and some others
from his area, feel that wake turbulence may have jolted the wing into
flutter. There were military aircraft flying low level practice
missions in the area where he went down, according to this guy.

He didn't think the fabric would have delaminated without some kind of
jolt.

I don't know, it was an old airplane that had been sitting around for
a long time and it was a relatively fast cruiser. It may have been
possible for the fabric to rip loose without any help from close
passing B1's.

Corky Scott

wrote

I vaguely remember reading in the FAA/NTSB archive about such an
incident. It was a while ago, so I may be a bit off. What I remember
was that the pilot was killed on impact and apparently he was aware of
some minor seperation and continued to fly the aircraft until it failed
catastrophically. Might have been another bird, but I think it was a
celebrity. I'm not 100% sure though. You might try searching the
accident database for the celebrity if you haven't already.

I am not an authority on the facts, so I didn't bring up the name of the
incident that I was thinking of, but since nobody else with all of the facts
has, I will.

Steve Whitman(sp?), namesake of the OSH airport, racer, and designer of the
Tailwind (among others) was killed in such an unbonding incident. I don't
recall the details, but I recall that he did something wrong, or against
other's recommendations.

The planes he designed were much higher performance crafts than what the OP
was asking about. I'm sure he can google the details.
--
Jim in NC

"Morgans" wrote in message
...

wrote

I vaguely remember reading in the FAA/NTSB archive about such an
incident. It was a while ago, so I may be a bit off. What I remember
was that the pilot was killed on impact and apparently he was aware of
some minor seperation and continued to fly the aircraft until it failed
catastrophically. Might have been another bird, but I think it was a
celebrity. I'm not 100% sure though. You might try searching the
accident database for the celebrity if you haven't already.

I am not an authority on the facts, so I didn't bring up the name of the
incident that I was thinking of, but since nobody else with all of the
facts
has, I will.

Steve Whitman(sp?), namesake of the OSH airport, racer, and designer of
the
Tailwind (among others) was killed in such an unbonding incident. I don't
recall the details, but I recall that he did something wrong, or against
other's recommendations.

That is my recollection as well. IIRC, he mixed and matched covering
processes and product "A" didn't get a good bond to product "B". Eventually
the bond failed, leading to flutter and a structural failure.

The planes he designed were much higher performance crafts than what the
OP
was asking about. I'm sure he can google the details.
--
Jim in NC

KB

It might be like that old rag-top car we've seen tooling down the highway
with the fabric ballooning away from the metal top when the adhesive gave
way. The altered profile might change the lift characteristics of the wing
to some degree I suspect. I read somewhere that anything above 75 should be
rib stitched, but I'm no engineer.
wrote in message
oups.com...
I was reading some information on Fisher Celebrity builders websites
and saw that one builder did not like the idea of glueing the fabric to
the ribs as per the plans. The ribs on the Celebrity are very thin and
he didn't think there was enough glue area for a satisfactory bond, so
he rib stitched.

I also recall reading somewhere that the glue area doesn't really
affect the strength of the bond between the fabric and wood rib ( which
I can't believe )

I know the wing loading of the Celebrity is low compared to some of the
more high performance bipes, but if the glue area is such a concern,
wouldn't it be OK to just increase the rib capstrip width slightly to
give more glueing area? Might only increase the whole airplane weight
half a pound.

Thoughts? Thanks

Neal

"Stan Premo" wrote in message
...
It might be like that old rag-top car we've seen tooling down the highway
with the fabric ballooning away from the metal top when the adhesive gave
way. The altered profile might change the lift characteristics of the
wing
to some degree I suspect.

The fabric lifting off the top of the wing can, and has killed people. This
is still not to say that it has to be stitched.

If loads on the surface are low enough that the correctly glued fabric stays
place, then all is well. Just make sure the correct techniques are used,
and that loads are low enough!
--
Jim in NC

Morgans wrote:


It might be like that old rag-top car we've seen tooling down the highway
with the fabric ballooning away from the metal top when the adhesive gave
way. The altered profile might change the lift characteristics of the
wing
snip


The fabric lifting off the top of the wing can, and has killed people. This
is still not to say that it has to be stitched.

If loads on the surface are low enough that the correctly glued fabric stays
place, then all is well. Just make sure the correct techniques are used,
and that loads are low enough!

What about the 3rd option from the Tony Bengals books, covering the wing
with thin fiber glass cloth and resin?

I know it would make it harder to inspect the condition of the wood
years down the road (sky?) but it sounds like it would last longer in
the first place.

Tony

Anthony W wrote:
Morgans wrote:


It might be like that old rag-top car we've seen tooling down the highway
with the fabric ballooning away from the metal top when the adhesive gave
way. The altered profile might change the lift characteristics of the
wing
snip


The fabric lifting off the top of the wing can, and has killed people. This
is still not to say that it has to be stitched.

If loads on the surface are low enough that the correctly glued fabric stays
place, then all is well. Just make sure the correct techniques are used,
and that loads are low enough!

What about the 3rd option from the Tony Bengals books, covering the wing
with thin fiber glass cloth and resin?

Just in case anyone wants to find his books its _Tony Bingelis.

Fiberglass wings are not fabric wings. You might as well say,
hey, why not cover them with aluminum sheet metal.

Also, I _think_ fiberglass wings will be heavier.

--

FF

wrote:

What about the 3rd option from the Tony Bengals books, covering the wing
with thin fiber glass cloth and resin?


Just in case anyone wants to find his books its _Tony Bingelis.

Fiberglass wings are not fabric wings. You might as well say,
hey, why not cover them with aluminum sheet metal.

Also, I _think_ fiberglass wings will be heavier.

I may have spelled his name wrong but from your answer, I don't think
you've read his books or at least this part.

Tony