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

Quite often hard landing damage such as this is prohibitively expensive to
repair. I suspect you'll find yet more damage inside the wings around the
landing gear attach points. People have tried unsuccessfully to make bush
airplanes out of Cherokees. Usually the airframe just gets bulldozed off the
side of some Alaska runway after a few months.

Karl

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...

kage wrote:
: Quite often hard landing damage such as this is prohibitively expensive to
: repair. I suspect you'll find yet more damage inside the wings around the
: landing gear attach points. People have tried unsuccessfully to make bush
: airplanes out of Cherokees. Usually the airframe just gets bulldozed off the
: side of some Alaska runway after a few months.

: Karl

Not everyone wants or needs a bush plane.
--
Aaron C.

C wrote:
: Hi folks,

: I ran into a little problem today.

problem snipped

This is probably due to someone torqueing the wing forward or aft at
some point. The wing flexes around the main spar and pulls or pushes on
the rear attatch fitting. This causes a crack in the spar carry through
right where yours is. The wing is 12' long, so even a small torque
applied at the tip gets "amplified" by the long lever arm.

The front attatch fitting is there really to hold on the leading edge
"glove" and doesn't take much force.

The main spar and rear attatch take all of the loads.

Hard landings cause cracks in the wing lower skins at the most inboard
point just in front of the main spar, which is covered by the long metal
fairing when assembled. Ripples on the lower aft wing skins also show up.
If this was done during a hard landing it was really a doozie.

My Cherokee 180 had similar damage on the left wing rear attatch fitting.
It was apparently damaged in 1969 when the left wing hit a runway light.
It was repaired without logs or 337's and went unnoticed until I bought it
in 2000. The mechanic that did the pre-buy found it. He said that it was
repaired just fine and not to worry unduly. Since the plane had 31 years and
5600 hours since the repair I think it is just fine, too. I don't believe
that there was a crack in the spar carry through on my plane, though.

The repair on my airplane involved cutting out the baggage compartment floor
about 6" aft of the rear spar carry through. The rear spar carry through
was replaced, picking up the rivets in the steel plate. A scab patch was
put on the outside of the fuselage. The baggage comp. floor was replaced
with a doubler on the inside along the cut line. It all was beautifully done.

If I can ever get over to the airport again, which may not be for 2-3 more
weeks, I can take some pictures if you wish.

--
Aaron Coolidge