Seaplane crash details

[Capt.Doug]

I tried to post some bitmap images with this but it didn't come up on my
server. Anyways..

Concerning the Chalks seaplane crash in Miami, fatigue features were
observed in the lower spar cap of the rear spar of the inboard end of the
right wing, bisecting 2 offset drilled holes.

D.

[Jay Beckman]

"Capt.Doug" > wrote in message
...
>I tried to post some bitmap images with this but it didn't come up on my
> server. Anyways..
>
> Concerning the Chalks seaplane crash in Miami, fatigue features were
> observed in the lower spar cap of the rear spar of the inboard end of the
> right wing, bisecting 2 offset drilled holes.
>
> D.

Capt,

This is a non-binary newgroup so most servers will strip the attachments.

You might try alt.binaries.pictures.aviation as a place to post them.

Regards,

Jay Beckman
PP-ASEL
Chandler, AZ

[Grumman-581]

"Jay Beckman" > wrote in message
news:ujkEf.24545$jR.8402@fed1read01...
> This is a non-binary newgroup so most servers will strip the attachments.
>
> You might try alt.binaries.pictures.aviation as a place to post them.

Or just post them to http://www.tinypic.com and then post the resultant URL
here... That's probably a better solution since that way, the photos stay
around... The photos in a binary newsgroup get flushed out eventually when
new ones come in, dependent upon the amount of traffic in the newsgroup...

[Mike Weller]

On Thu, 02 Feb 2006 09:26:20 GMT, "Capt.Doug" >
wrote:

>I tried to post some bitmap images with this but it didn't come up on my
>server. Anyways..
>
>Concerning the Chalks seaplane crash in Miami, fatigue features were
>observed in the lower spar cap of the rear spar of the inboard end of the
>right wing, bisecting 2 offset drilled holes.
>
>D.
>

Send them to me.

I've got the web space to share them.

I'm not a lawyer, I'm just an engineer that is interested in metal
fatigue and aging aircraft.

In particular, I'm going to buy an old 7AC or L-16.

Mike Weller

[Capt.Doug]

>"Mike Weller" wrote in message > Send them to me.

They are on the way.

D.

[Dudley Henriques]

"Capt.Doug" > wrote in message
...
>I tried to post some bitmap images with this but it didn't come up on my
> server. Anyways..
>
> Concerning the Chalks seaplane crash in Miami, fatigue features were
> observed in the lower spar cap of the rear spar of the inboard end of the
> right wing, bisecting 2 offset drilled holes.
>
> D.

This scenario is almost the same scenario that killed a friend of mine in
his F8F Bearcat. As these old airplanes age, even with constant care, it's
extremely difficult to assess the actual wearing down process on a specific
spot taking accumulated stress over time.
Sooner or later, subjected to the dynamics involved with in-flight forces,
all parts will deteriorate as we all know.

Finding that "sweet spot" that defines total runout time for every piece of
an airplane can be a daunting task. You can inspect, you can magnaflux, you
can estimate a failure mode through a computer model, but in the end,
something can and usually will give somewhere.
What's insidious in all this is that when these failures happen, they come
in two different scenarios. The first is obvious; a total failure of a part
which is instantly catastrophic such as was the case with my friend's
Bearcat where the wing sheared off the airplane coming out of a normal loop
at normal g, or the failure of a minor part which isn't instantly
catastrophic, but however instantly changes the entire failure model for
parts down the line that are affected by the minor part's failure.
It's a tough call on these old airplanes, and something that will be talked
about and debated by those involved in flying older airplanes without
finding a definitive answer ad infinitum.
Total replacement of a part based on an estimated failure span is good, but
even with that in place, considering the astronomical cost of doing this,
flying these old airplanes past their projected airframe runout I think will
always be a crapshoot.
Dudley Henriques

[Dudley Henriques]

Mike;
If you're interested in 7AC's I think Todd Pattist bought one recently. You
might want to check with him on whatever fabric tests he did.
Dudley Henriques


"Mike Weller" > wrote in message
...
> On Thu, 02 Feb 2006 09:26:20 GMT, "Capt.Doug" >
> wrote:
>
>>I tried to post some bitmap images with this but it didn't come up on my
>>server. Anyways..
>>
>>Concerning the Chalks seaplane crash in Miami, fatigue features were
>>observed in the lower spar cap of the rear spar of the inboard end of the
>>right wing, bisecting 2 offset drilled holes.
>>
>>D.
>>
>
> Send them to me.
>
> I've got the web space to share them.
>
> I'm not a lawyer, I'm just an engineer that is interested in metal
> fatigue and aging aircraft.
>
> In particular, I'm going to buy an old 7AC or L-16.
>
> Mike Weller
>
>
>
>

[Capt.Doug]

>"Dudley Henriques" wrote in message
> Total replacement of a part based on an estimated failure span is good,
but
> even with that in place, considering the astronomical cost of doing this,
> flying these old airplanes past their projected airframe runout I think
will
> always be a crapshoot.

The airframe doesn't need to be old. Cape Air has installed spar straps in
their C-402C fleet (47 C-402s) after an incident which inspired the Cessna
400 series wingspar AD.

D.

[James Robinson]

Mike Weller > wrote:

> "Capt.Doug" > wrote:
>
>> I tried to post some bitmap images with this but it didn't come up on
>> my server. Anyways..
>>
>> Concerning the Chalks seaplane crash in Miami, fatigue features were
>> observed in the lower spar cap of the rear spar of the inboard end of
>> the right wing, bisecting 2 offset drilled holes.
>>
> Send them to me.
>
> I've got the web space to share them.
>
> I'm not a lawyer, I'm just an engineer that is interested in metal
> fatigue and aging aircraft.

In case you hadn't seen it, there are a couple of articles on the Flight
International web site, with photos of the cracking and some short
discussion:

http://tinyurl.com/brcwy
http://tinyurl.com/9kslp

[Dudley Henriques]

"Capt.Doug" > wrote in message
...
> >"Dudley Henriques" wrote in message
>> Total replacement of a part based on an estimated failure span is good,
> but
>> even with that in place, considering the astronomical cost of doing this,
>> flying these old airplanes past their projected airframe runout I think
> will
>> always be a crapshoot.
>
> The airframe doesn't need to be old. Cape Air has installed spar straps in
> their C-402C fleet (47 C-402s) after an incident which inspired the Cessna
> 400 series wingspar AD.
>
> D.
>

This is absolutely true.
I didn't mean to imply that only older airframes are affected. All airframes
are affected starting from the first day they become operational. Sometimes
it's caught and an AD is issued, but many times, especially with older
airplanes, the issue misses the AD route and just lies there waiting.
I can remember 1 AD involving the P51D during the time I was involved with
the airplane, and that one was on the 24D50 Hamilton prop. Just imagine
projecting the failure timeouts for the rest of the airframe as we used it
for display work. Thank God we were fairly good at estimating.
:-)
Dudley Henriques

[Montblack]

("Dudley Henriques" wrote)
> If you're interested in 7AC's I think Todd Pattist bought one recently.
> You might want to check with him on whatever fabric tests he did.

[Mike Weller]
>> In particular, I'm going to buy an old 7AC or L-16.


I believe Steven P. McNicoll flys a 7AC.


Montblack

[Dudley Henriques]

I think you're right. McNicoll does fly a Champ!
Good luck with your quest. The Champ is a fine old bird.
DH

"Montblack" > wrote in message
...
> ("Dudley Henriques" wrote)
>> If you're interested in 7AC's I think Todd Pattist bought one recently.
>> You might want to check with him on whatever fabric tests he did.
>
> [Mike Weller]
>>> In particular, I'm going to buy an old 7AC or L-16.
>
>
> I believe Steven P. McNicoll flys a 7AC.
>
>
> Montblack