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

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

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.

On Tue, 5 Apr 2005 19:50:56 -0700, "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

I agree, some people attempt to use planes like this for purposes they
were not built to withstand. But I don't think this was the case with
this Cherokee. Its been well tended by past owners, upgraded quite a
bit, and even preventative maintenance shows in the logs. Also, all
ADs show compliance in the logs. The last owner was a nice gentleman
up in Mass who used it to travel to see his son occasionally. And the
one before him was a minister in the northeast. So, no nuts in the
outback.

We've additionally been all over the wings and landing gear recently
(reoccuring AD on gear links) -- no problems at all. The wings and
fuselage don't show any wrinkling or other signs of high stress/hard
landings. This one frame member is the only damage we can find
anywhere -- and only on one side.

Luckily, I've been able to track down a couple places that have that
part on hand. It looks like it will cost a pretty penny to get it and
have it installed (a lot of riveting involved) -- but this one part
should resolve the problem.



Chuck

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

I wonder if this caused it:


FAA Accident/Incident Information
#FAA1 Accident/Incident Occurred on: 1991-10-18
Narrative: PILOT LOST CONTROL OF AIRCRAFT ON ROLLOUT. VEERED OFF
RUNWAY. LATER STATED CAUSE WAS A WIND GUST.







"C" wrote in message
...
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

Steve Foley wrote:
I wonder if this caused it:
FAA Accident/Incident Information
#FAA1 Accident/Incident Occurred on: 1991-10-18
Narrative: PILOT LOST CONTROL OF AIRCRAFT ON ROLLOUT. VEERED OFF
RUNWAY. LATER STATED CAUSE WAS A WIND GUST.

Jeez, I hope not. That means it would have gone through 13 or 14 annuals
with no one noticing the crack!

--- Jay




"C" wrote in message
...
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




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

Steve Foley wrote:
I wonder if this caused it:


FAA Accident/Incident Information
#FAA1 Accident/Incident Occurred on: 1991-10-18
Narrative: PILOT LOST CONTROL OF AIRCRAFT ON ROLLOUT.
VEERED OFF
RUNWAY. LATER STATED CAUSE WAS A WIND GUST.

That very well could be it. Departing the runway on to rough ground
can cause the fore/aft stresses that generally cause these types of
cracks.

John Galban=====N4BQ (PA28-180)

C wrote:
: 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.

Wow... that looks ugly. I just spend an inordinate amount of time looking at
the exact same area of my -140/180. We got FSDO approval for a 337 to add a -180
baggage floor back there. I spend 2 full weekends folded into a pretzel in the tail
of mine drilling out old rivets, drilling holes for, squeezing solid, and popping
blind new ones in.... all with the A&P saying, "Man, that looks uncomfortable." I was
quite disturbed about having to remove and replace a half dozen rivets on the
important-looking steel attach brackets in the corners. I'll be really ****ed if it
becomes an AD that requires removing the whole damn thing again!

I like the poster's explanation that it's a fore-aft torque that rippled it...
not a hard landing. A hard landing usually tries to push the mains struts through the
top of the wing, IIRC.

-Cory


************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

Well,

For anyone who was following -- we finished up the last of the repairs
yesterday and the last paperwork today. And I took her out for an
hour or so to check everything.

I'll have to post the whole story soon, when I have a bit of time.
But I learned a lot about FAA rules, 337s, DERs, 8110.3s, and other
red tape that comes with repairing damage to a certified plane. It
might help others -- but it IS one big pain!!!

Of course, it wasn't helped by a local FSDO Airworthyness Inspector
who didn't know his **** and kept pulling rules out of thin air. My
A&P and IA laughed most of the time and blew him off -- but it kept
putting a stop to the repair process and drew it out to three weeks to
do a three day job. That's OK, I'm filing a formal complaint -- we'll
see how much he learns after that...


Chuck
N7398W




On Tue, 05 Apr 2005 03:28:58 GMT, C wrote:

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

On Wed, 27 Apr 2005 06:41:25 GMT, Chuck wrote:

Of course, it wasn't helped by a local FSDO Airworthyness Inspector
who didn't know his **** and kept pulling rules out of thin air. My
A&P and IA laughed most of the time and blew him off -- but it kept
putting a stop to the repair process and drew it out to three weeks to
do a three day job. That's OK, I'm filing a formal complaint -- we'll
see how much he learns after that...

Picking a fight with the FAA? Careful - don't get Bob Hoover'ed.