PLEASE NEED HELP with Cherokee 180 metal bulkhead problem under back seat

Hi folks,

I ran into a little problem today.

Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.

However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.

Has anyone run into this problem before? I'd love to hear what had to
be done to repair/replace the damage. Maybe someone knows of a 337
that had been done to repair similar damage??? It would sure help my
mechanic who is a little unsure of where to start in the repair
process.

Thanks guys...



Chuck
N7398W

If you are a member of the Cherokee Pilots Association, asking this question
on their "Cherokee Chat" web page would net you quite a few good responses.

See www.Piperowner.com .

Sounds like you've got some pretty major damage there. Is any of it noted
in the logbooks? (I'll bet I know the answer to *that* question...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

C wrote:
Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.

I'd be carefull jumping to the conclusion that's it isn't structural.
That steel plate is the rear wing attach fitting. And I believe the
bulkhead that it's attached to is considered the "rear spar carry through"
(like a "mini" spar). Cherokee's have a large center spar, but also have
a front and rear attach point and carry through. The front carry through
is behind where your heels sit when you're in the pilot's seat (under the
plastic trim pieces). The rear one is where you describe.


However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.

There was a person on the Cherokee Chat (see Jay Honeck's post) a few
weeks ago that had very similar crack and he posted pictures. I hope this
isn't the beginning of a trend, or we'll be seeing an AD soon.

You're correct in assuming a "terrific upward stress", although I would
have hoped that a hard landing or bad turbulence wouldn't have caused such
damage. You'll want to make sure you have a very competant mechanic fix
this. Wing departure, or severe twist, while in flight would really suck.
You might want to show this to your local FSDO, too. I hate to encourage
and AD, but this could be a problem we might not want to ignore.

--- Jay


--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

On 05 Apr 2005 15:58:08 GMT, (Jay Masino)
wrote:

C wrote:
Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.

I'd be carefull jumping to the conclusion that's it isn't structural.
That steel plate is the rear wing attach fitting. And I believe the
bulkhead that it's attached to is considered the "rear spar carry through"
(like a "mini" spar). Cherokee's have a large center spar, but also have
a front and rear attach point and carry through. The front carry through
is behind where your heels sit when you're in the pilot's seat (under the
plastic trim pieces). The rear one is where you describe.


However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.

There was a person on the Cherokee Chat (see Jay Honeck's post) a few
weeks ago that had very similar crack and he posted pictures. I hope this
isn't the beginning of a trend, or we'll be seeing an AD soon.

You're correct in assuming a "terrific upward stress", although I would
have hoped that a hard landing or bad turbulence wouldn't have caused such
damage. You'll want to make sure you have a very competant mechanic fix
this. Wing departure, or severe twist, while in flight would really suck.
You might want to show this to your local FSDO, too. I hate to encourage
and AD, but this could be a problem we might not want to ignore.

--- Jay

Funny you mention that...

I talked to the maintenance person at the FSDO today about this
problem. As soon as I mentioned that I had a Cherokee with a damaged
"Frame Assembly Lower Station" -- he replies "The one under the back
seat?". WOW! I'd hate to think this is a common problem.

Its looking like I'll either have to replace it with the same part
scavenged from another Cherokee, or call in a DER to design a fix and
then do the fix. Either way -- its going to be expensive!

I'm thinking that I'm going to go after a A&P for the cost though. I
paid a A&P for a pre-buy/annual less than a year ago. This problem is
not new -- someone tried a half-assed, partial fix with some rivits.
So, the problem was definitely known, not in the logs, not repaired,
and NOT identified during his annual inspection. And this was
something a regular A&P spotted as soon as we lifted the rear seat.
So, I think I'm going to AT LEAST get my payment for the pre-buy back
if not get full payment for repairs.

See attached picture. Sorry for the grime, I haven't had a chance to
clean up under that seat yet.


Chuck

C wrote:

On 05 Apr 2005 15:58:08 GMT, (Jay Masino)
wrote:


C wrote:

Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.

I'd be carefull jumping to the conclusion that's it isn't structural.
That steel plate is the rear wing attach fitting. And I believe the
bulkhead that it's attached to is considered the "rear spar carry through"
(like a "mini" spar). Cherokee's have a large center spar, but also have
a front and rear attach point and carry through. The front carry through
is behind where your heels sit when you're in the pilot's seat (under the
plastic trim pieces). The rear one is where you describe.



However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.

There was a person on the Cherokee Chat (see Jay Honeck's post) a few
weeks ago that had very similar crack and he posted pictures. I hope this
isn't the beginning of a trend, or we'll be seeing an AD soon.

You're correct in assuming a "terrific upward stress", although I would
have hoped that a hard landing or bad turbulence wouldn't have caused such
damage. You'll want to make sure you have a very competant mechanic fix
this. Wing departure, or severe twist, while in flight would really suck.
You might want to show this to your local FSDO, too. I hate to encourage
and AD, but this could be a problem we might not want to ignore.

--- Jay


Funny you mention that...

I talked to the maintenance person at the FSDO today about this
problem. As soon as I mentioned that I had a Cherokee with a damaged
"Frame Assembly Lower Station" -- he replies "The one under the back
seat?". WOW! I'd hate to think this is a common problem.

Its looking like I'll either have to replace it with the same part
scavenged from another Cherokee, or call in a DER to design a fix and
then do the fix. Either way -- its going to be expensive!

I'm thinking that I'm going to go after a A&P for the cost though. I
paid a A&P for a pre-buy/annual less than a year ago. This problem is
not new -- someone tried a half-assed, partial fix with some rivits.
So, the problem was definitely known, not in the logs, not repaired,
and NOT identified during his annual inspection. And this was
something a regular A&P spotted as soon as we lifted the rear seat.
So, I think I'm going to AT LEAST get my payment for the pre-buy back
if not get full payment for repairs.

See attached picture. Sorry for the grime, I haven't had a chance to
clean up under that seat yet.


Chuck


attachments don't work on the newsgroups. You'll need to put it on a
website if you want us to be able to see it

Well I could see the photograph real well.
But the problem looks quite bad, I am checking my Archer in the same area.

--
Roy
N5804F - PA28-181 Piper Archer II




"xyzzy" wrote in message
...
C wrote:

On 05 Apr 2005 15:58:08 GMT, (Jay Masino)
wrote:


C wrote:

Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.

I'd be carefull jumping to the conclusion that's it isn't structural.
That steel plate is the rear wing attach fitting. And I believe the
bulkhead that it's attached to is considered the "rear spar carry
through"
(like a "mini" spar). Cherokee's have a large center spar, but also have
a front and rear attach point and carry through. The front carry through
is behind where your heels sit when you're in the pilot's seat (under the
plastic trim pieces). The rear one is where you describe.



However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.

There was a person on the Cherokee Chat (see Jay Honeck's post) a few
weeks ago that had very similar crack and he posted pictures. I hope
this
isn't the beginning of a trend, or we'll be seeing an AD soon.

You're correct in assuming a "terrific upward stress", although I would
have hoped that a hard landing or bad turbulence wouldn't have caused
such
damage. You'll want to make sure you have a very competant mechanic fix
this. Wing departure, or severe twist, while in flight would really
suck. You might want to show this to your local FSDO, too. I hate to
encourage
and AD, but this could be a problem we might not want to ignore.

--- Jay


Funny you mention that...

I talked to the maintenance person at the FSDO today about this
problem. As soon as I mentioned that I had a Cherokee with a damaged
"Frame Assembly Lower Station" -- he replies "The one under the back
seat?". WOW! I'd hate to think this is a common problem.

Its looking like I'll either have to replace it with the same part
scavenged from another Cherokee, or call in a DER to design a fix and
then do the fix. Either way -- its going to be expensive!

I'm thinking that I'm going to go after a A&P for the cost though. I
paid a A&P for a pre-buy/annual less than a year ago. This problem is
not new -- someone tried a half-assed, partial fix with some rivits.
So, the problem was definitely known, not in the logs, not repaired,
and NOT identified during his annual inspection. And this was
something a regular A&P spotted as soon as we lifted the rear seat.
So, I think I'm going to AT LEAST get my payment for the pre-buy back
if not get full payment for repairs.

See attached picture. Sorry for the grime, I haven't had a chance to
clean up under that seat yet.


Chuck


attachments don't work on the newsgroups. You'll need to put it on a
website if you want us to be able to see it

xyzzy wrote:

attachments don't work on the newsgroups. You'll need to put it on a
website if you want us to be able to see it

Attachments work, some ISPs don't allow or filter them, I received it
just fine...

You can view it he

http://www.whodat.net/cherokee180/damage.jpg

Shame mine doesn't filter excessive quotation...

Some years ago I repaired a Pawnee that had a similar steel plate on
the front spar. Because of the steel on aluminum, there was extensive
corrosion between and the aluminum rivets were soft enough you could
pick off the heads of the #6 rivets with your finger nail.

From the looks of the photo, there is lots of rust, meaning water.
Aluminum + steel + water = battery = corrosion. If it were mine, I'd
take it apart and look to see what is going on. If the aluminum is
corroded under the steel, you could get cracks under normal loads.

Don
A&P - IA

Posted Via Usenet.com Premium Usenet Newsgroup Services
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Sorry to break the news to you, but that definitely IS structural. And
this is not an easy fix. The fitting on the left is the rear spar attach
fitting. What you are looking at is the aftermath of a fairly severe
"excursion" of the rear spar on that wing, probably front to back. I'm
not sure where you see repairs and extra rivets. Those on the attach
fitting and the ones going through the floor are all supposed to be
there. I do see the corrosion forming behind the fitting that is the
subject of a Piper Service Bulletin.

Good luck trying to hold someone accountable on a pre buy. I highly
doubt you will get anything back. For all the A&P knows, this damage
could have occurred after his inspection. Ever notice any new scrapes on
the affected wing leading edge or it's control surfaces, especially
towards the tip? This may have been a close encounter with a hangar door
or fuel truck. It does not take a huge amount of lateral pressure at the
wing tip to produce the type of damage in the photo. These wings are
made tremendously strong to not bend UP and quite strong to not bend
DOWN. But the only thing keeping them from moving front to back is the
rear spar and its attach point. Yours clearly flexed in and out.

Let us know what your repair quote is.

Mike

xyzzy wrote:

C wrote:

On 05 Apr 2005 15:58:08 GMT, (Jay Masino)
wrote:


C wrote:

Working on a 100hour just a month before the annual is due -- my
mechanic and I lifted the back seat to look at the cabling underneath.
Lo and behold -- we found a "tear" in an aluminum bulkhead under the
back seat.

The bulkhead is under the back of the rear seat and doesn't appear to
be structural as it is thin aluminum. But there is a steel brace
coming in from the flap area of the wing and rivited to the lower
outside corner of the aluminum bulkhead.


I'd be carefull jumping to the conclusion that's it isn't
structural. That steel plate is the rear wing attach fitting. And I
believe the
bulkhead that it's attached to is considered the "rear spar carry
through"
(like a "mini" spar). Cherokee's have a large center spar, but also
have
a front and rear attach point and carry through. The front carry
through
is behind where your heels sit when you're in the pilot's seat (under
the
plastic trim pieces). The rear one is where you describe.



However on mine, just next to the steel brace on the baggage door side
-- there is a inch long tear up from the bottom of the bulkhead and a
small buckle in the aluminum brace above the tear. Its like there was
a terrific upwards stress on the bottom corner of the bulkhead where
the steel is rivited and it tore the aluminum bulkhead upwards.


There was a person on the Cherokee Chat (see Jay Honeck's post) a few
weeks ago that had very similar crack and he posted pictures. I hope
this
isn't the beginning of a trend, or we'll be seeing an AD soon.

You're correct in assuming a "terrific upward stress", although I would
have hoped that a hard landing or bad turbulence wouldn't have caused
such
damage. You'll want to make sure you have a very competant mechanic fix
this. Wing departure, or severe twist, while in flight would really
suck. You might want to show this to your local FSDO, too. I hate
to encourage
and AD, but this could be a problem we might not want to ignore.

--- Jay



Funny you mention that...

I talked to the maintenance person at the FSDO today about this
problem. As soon as I mentioned that I had a Cherokee with a damaged
"Frame Assembly Lower Station" -- he replies "The one under the back
seat?". WOW! I'd hate to think this is a common problem.

Its looking like I'll either have to replace it with the same part
scavenged from another Cherokee, or call in a DER to design a fix and
then do the fix. Either way -- its going to be expensive!

I'm thinking that I'm going to go after a A&P for the cost though. I
paid a A&P for a pre-buy/annual less than a year ago. This problem is
not new -- someone tried a half-assed, partial fix with some rivits.
So, the problem was definitely known, not in the logs, not repaired,
and NOT identified during his annual inspection. And this was
something a regular A&P spotted as soon as we lifted the rear seat.
So, I think I'm going to AT LEAST get my payment for the pre-buy back
if not get full payment for repairs.

See attached picture. Sorry for the grime, I haven't had a chance to
clean up under that seat yet.


Chuck


attachments don't work on the newsgroups. You'll need to put it on a
website if you want us to be able to see it


__________________________________________________ _____________________________
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Sorry to break the news to you, but that definitely IS structural. And
this is not an easy fix. The fitting on the left is the rear spar attach
fitting. What you are looking at is the aftermath of a fairly severe
"excursion" of the rear spar on that wing, probably front to back. I'm
not sure where you see repairs and extra rivets. Those on the attach
fitting and the ones going through the floor are all supposed to be
there. I do see the corrosion forming behind the fitting that is the
subject of a Piper Service Bulletin.

Good luck trying to hold someone accountable on a pre buy. I highly
doubt you will get anything back. For all the A&P knows, this damage
could have occurred after his inspection. Ever notice any new scrapes on
the affected wing leading edge or it's control surfaces, especially
towards the tip? This may have been a close encounter with a hangar door
or fuel truck. It does not take a huge amount of lateral pressure at the
wing tip to produce the type of damage in the photo. These wings are
made tremendously strong to not bend UP and quite strong to not bend
DOWN. But the only thing keeping them from moving front to back is the
rear spar and its attach point. Yours clearly flexed in and out.

Let us know what your repair quote is.

Mike

Hi Mike,

I met with a DER yesterday who has designed a repair for the damage.
Its not going to be as bad as first thought. And while the DER design
(plus 8110 form for FAA) cost was $450, the repair costs probably
won't push behond $1,000.

Talking with the DER, we're pretty sure we figured out when this
happened. The only damage history on the plane was an "off-runway"
excursion back in '92. The logs show the nose gear collapsed, the
engine/cowl stuck, and of course a sudden engine stop. The logs show
the engine teardown/rebuild and replacing everything forward of the
firewall, but that's it. We're pretty sure the sudden rearward force
on the mains as it departed the runway flexed the rear of the wing
upward and caused this damage.

If you look closely at the first picture posted on the 10th, you can
see two cherry-max rivets into the bottom flange from the outside
(rivets so poorly installed that they wiggle). THAT is how I know
this repair was previously known. I also recently found out that the
person I hired for the prebuy (on a referral) was the same person who
had been maintaining the plane for a number of years. So, the
suggestion that an A&P/IA would miss such damage through multiple
annuals and a pre-buy is just plan nonsense. If he is THAT
incompetent -- he shouldn't have a license to screw up further work.

Anyway - thanks for the information Mike. None of that mess was
corrosion by the way -- its just years of dirt/dust mixed with spray
on lubricant. The first picture shows it after I brushed it a bit and
vacuumed. I'm off tomorrow for a bunch of rivet pulling, buying some
aluminum, and riveting in repairs. I'll be sure to post a couple
pictures when we finish the designed repairs.


Chuck
N7398W