[Kyle & Velvet]

Kyle & Velvet on September 5, 2022 at 4:52 pm #21519

I have a ’67 PA28-180 that I keep in my hanger. During the annual this year we discovered a crack in the skin of the right underside wing. We grounded the plane and started looking at the possibility of much larger issues that might have caused this. This crack was not a complete surprise to us. It had developed a number of years prior and had been stop-drilled. The surprise was that it had doubled in size since the last annual. The only operational difference to the plane was now being operated out of a grass strip and not a concrete one. My AI inspected the spar and found nothing amiss. We contacted Piper engineering, but they are swamped and understaffed. The DER I spoke to said that this was not an uncommon issue and would be repairable.
I would like to reach out to the Cherokee community and see if anyone else has dealt with this and what was the solution/outcome.

Thanks
Kyle Sims
CaptainKyle1@gmail.com

Attachments:

• PXL_20220807_144824804.jpg
• PXL_20220807_145120901.jpg

[STEVE]

STEVE on September 6, 2022 at 6:45 pm #21522

Hi Kyle,
Thanks for reaching out. It’s a new one to me, but that doesn’t mean much–I don’t know everything.
But I will start asking around and let you know what I find.
Steve

[STEVE]

STEVE on September 7, 2022 at 2:17 am #21524

Kyle;
I’m very interested in your Cherokee wing problem.
A couple of questions:
Have you removed the fuel tank in an attempt to get a good look at the inside of the wing?
In lieu of that, because it isn’t be best way to inspect the aft side of the wing spar, have you installed Piper Service Kit 765-106V called out in Piper Service Bulletin SB 1304 (attached).
I am suggesting this because there are a number of cases of bad corrosion on the wing spar.
I am also interested in the DER who told you that this is a common PA 28 problem and is easy to repair.
If corrosion is rampant in your wing spar area of your right wing, I suspect that it may have weakened the skin enough for this type of fracture.
As you point out, the only difference is you’re now operating off a grass strip. It it’s not real smooth, that must have been the cause of the crack doubling in length over a one year period.
I’m still calling around looking for guidance on this.
Please l et me know what you find out.
Steve

Attachments:

• SB13046772WingMainSparInsp_2022-09-06.pdf

[STEVE]

STEVE on September 7, 2022 at 8:30 pm #21526

Hi Kyle;
A very highly regarded airframe rebuild company told me that the crack in not unusual. It opined that it’s caused by that skin flexing repeatedly until it breaks.
The same company (Airframe Components in Kendallville, Indiana) said that Piper recognized the problem and new wing skins for that area have a reinforcement.
It told me the best solution is to remove the wing to replace the skin. Removing the wing isn’t a very difficult job.
Airframe Components also told me that attempts to stop drill the crack have to be done with extreme caution because there’s a flange that’s part of the wing spar in that area. If the stop drill damages that flange, the wing spar will need to be replaced.
As I mentioned earlier, one way to get access to the crack area is to remove the fuel tank. Then you and your mechanic can better see the damaged area.
I doubt that this is what you wanted to hear, but it’s good information.
My suggestion is to removed the fuel tank, and get a good look at the damaged area, and take pictures.
Let me know how I can help.

Steve

[Kyle & Velvet]

Kyle & Velvet on September 8, 2022 at 5:58 pm #21529

We have installed the Access panel per the SD a few year ago. It looks like we can get to everything without any issues. The DER did not say it was going to be an easy fix, just that it was fixable. I have been out flying this week, but I will get back to the DER for the full instructions next week.
Kyle Sims

[STEVE]

STEVE on September 12, 2022 at 11:17 pm #21552

Kyle,
OK, it sounds like you’re going in the right direction.
I want to re state what the wing repair shop emphasized–look to make sure the stop drill did not go into any part of the wing spar.

I’d love to know more when you get to it.

Best,
Steve